Military recon powerboat concept [Archive]

Quicksilver

12-19-2006, 03:58 PM

On the topic of this thread, I dont see the feasibility of this design, besides the obvious, is this craft to be jet turbine driven. By using the turbines thrust? If so, I think thats pretty inefficient and not proven as a design. Besides those after burners have a bit of a heat signature. The craft could be turbine powered, but imo it would have to be prop driven. That's the only way I've seen it work, like the world record holder for offshore racing. This boat over 200mph, with turbines, but with props. Not to mention how do you steer it? If its with sub surface rudders this further, reducing the need for the use of jets. You need thrust vectoring or something, but still jets big enough to propel this thing with thrust would burn a ridiculous amount of fuel and make the boat imo prone to flying rather then skimming.

Also, this boat is merely for scouting? I hope so, otherwise theres no way of production, unless it has some tactical weaponry. I mean you can even go out on the deck to shoot or apprehend people.
I'm not try to rip apart the design, but we werent given hardly any info, so I have to assume some things.

I could see this craft with twin apache turbines, twin surface piercing shrouded drives, with the hull protruding over the drives, to further reduce spray. Maybe throw in a hellfire missile launcher, gattling guns and cruise missile launchers. I'd buy that :)

Verytricky

12-19-2006, 08:56 PM

Maybe throw in a hellfire missile launcher, gattling guns and cruise missile launchers.
That would be useful on the Solent for the Rag & Stick brigade....

Power gives way to sail my ass! Sail gives way to my 22mil cannon!:cool:

kach22i

12-19-2006, 10:11 PM

I could see this craft with twin apache turbines, twin surface piercing shrouded drives, with the hull protruding over the drives, to further reduce spray. Maybe throw in a hellfire missile launcher, gattling guns and cruise missile launchers. I'd buy that :)
That's right out of the old "Mortal Combat" movie.:D

It is!

The problem with high speed craft is letting them know you are coming. A giant roostertail of water shows up pretty good on radar I hear, and can be seen from a distance.

I made my first comments without seeing the images, he had a double post, one post had no images.

I guess it's just a fun ride to post bogus images for some people. Nice renderings even if they are not thought out very carefully.

StianM

12-20-2006, 12:00 AM

Stealth my ass.

With the turbine outlets in the rear you have a heat signature big as a smal european country.

I would go for the same concept as KNM Skjold.

They use skirts like a howercraft betwen the hulls and let the exhaust out there.

Quicksilver

12-20-2006, 01:08 AM

That's right out of the old "Mortal Combat" movie.:D

It is!

The problem with high speed craft is letting them know you are coming. A giant roostertail of water shows up pretty good on radar I hear, and can be seen from a distance.

I made my first comments without seeing the images, he had a double post, one post had no images.

I guess it's just a fun ride to post bogus images for some people. Nice renderings even if they are not thought out very carefully.

Well I didnt say it would be stealth, but it would be a lot more stealth than jets sticking out the back. Either way, think of the noise, look up the Callan
racing boat on "you tube". The thing is unbelievably loud. Fast but my god I'd hear that that thing coming, the only stealth might come from not knowing it was a boat, thinking it was an F-14

btw I must have missed that part of mortal combat, I saw but only kinda saw it.

safewalrus

12-20-2006, 02:50 PM

Remember as has been said above stealth ain't just about low radar signature! People got ears and can use 'em so you need QUIET engines (USof A don't do quiet :rolleyes: ), no wake and no heat! When to use matters too! Little bit of rough weather and its a submarine - straight to the bottom!:D

brian eiland

12-20-2006, 03:08 PM

It wouldn't surprise me at all, some of the crazy stuff that gets contracts here in Washington DC.

M-Hull, M hull, M Ship
http://boatdesign.net/forums/showthread.php?t=5687

StianM

12-21-2006, 12:04 AM

http://www.knmskjold.org/

This cat has skirts in the front and the rear. fans are pumping in air and lifting it like a howercraft reducing hull resistance.

the exhaust from the 4 turbines is let out betwen the hulls so the exhaust outlet can't be seen from anny angle unless you take off the skirts.

The skirts also absorb some sound I asume.

4 turbines driving 2 waterjets and speed is about 60kn.

I gues they use coolingwater from reduction gears and other mecinery to cool down the exhaust too.

I think it's this one and one thay build in sweeden that is the best projects on this so far so it should be the way to go.

kach22i

12-21-2006, 06:31 AM

http://www.knmskjold.org/

This cat

It's not a "cat", it's sometimes called a SEC or SES standing for Surface Effect Craft or Ship. The skegs or fins on the side just keep the air in, they do not provide lift, the air pressure does that. They typically are just wide enough to get the drive systems through them.

The US Navy last time I read is supposed to purchase some of these craft in lieu of paying some American company to develop one of their own, guess they want to save some money. How unAmerican.:D

That is a great website Stian, one I have not seen before - thanks.

brian eiland, I've posted the "M-Hull" ship in several forums, did not know you have done the same here. I must of missed that thread, thanks for that link as well.

http://www.hoverclubofamerica.org/forum/index.php?showtopic=698&st=0&gopid=8583&#entry8583

More wacky stuff here:
http://www.hoverclubofamerica.org/forum/index.php?showtopic=460&hl=Skjold

yipster

12-21-2006, 10:09 AM

i like the sketches but am negative on the concept, time to counter intelligenge first? :idea:
do like that Callan tho

DryFoot

12-22-2006, 10:10 PM

Not much (almost none) boating experience here, but my back ground is military:

What purpose exactly would this boat serve? Recon can be done much cheaper with UAV and electronic method. Also, what speedboats they have are mostly SEAL delivery vehicles. Without a dimension listed and just looking at the shape, I would say this vehicle would not serve that purpose too well due to what appears to be very limited personnel carrying capacity.

Now, if this is suppose to be a gun/torpedo boat: Too small for torpedo, i would guess. Most anti-ship torpedos would be the length of this thing, not to mention it would be too heavy. As a gunboat, the hull does not seem very indusive to manned weapon mount, and any remote control weapon on this thing would be either: A, too light to do anygood against anything but personnel, or B: Too heavy to be carried by a speed boat.

Stealth technology is probably going to be wasted on a ship like this, no way an application of something like this (unless converted into a SEAL delivery vehicle of dubious functionality) warrants the use of stealth technology and the extra cost associated.

This boat does remind me of that Hulk Hogan show Thunder in Paradise though.

The US Navy last time I read is supposed to purchase some of these craft in lieu of paying some American company to develop one of their own, guess they want to save some money. How unAmerican.
Current M-16 manufacturer: Fabrique National
M-9 manufacturer: Beretta
M-249: FN
M-240: FN
M-11: SIG
SOCOM pistol: H&K
MP5: H&K
AT-4: Saab
SMAW: IMI

Hey, that's the current trend.

kach22i

12-23-2006, 09:39 AM

Even the US military is required to obtain a wavier to the Jones Act. Then there is the whole political thing which includes providing high paying civilian jobs for those guys leaving the service.

It's not what you know, it's who you know.

Example;
http://www.hoverclubofamerica.org/forum/index.php?act=post&do=edit_post&f=8&t=648&p=8513&st=30

The "Loop Hole" was created by the same Congress that past the Jones Act! The short of it is that a Foriegn Designer / Builder can "license" a design and technology to an American Shipyard. Providing the design passes the USCG Design Review process and meets or exceeds safety regulations. The American shipbuilder gets "work" but the real profits go out of the country!

Some foriegn made vessels have been granted an "waiver" under the Jones Act but it is not easy to get. The US Military can also get "waivers" or "contract" for special needs. The Government always gets what they want! If you dig a little deeper you will find that Bell Aerospace actually built Military Hovercraft during the Vietnam War in the Buffalo New York facility so they were Jones Act Compliant.

UPDATE 12/12/06:

Right.

http://findarticles.com/p/articles/mi_m0FZ...69/ai_111852741 (http://findarticles.com/p/articles/mi_m0FZX/is_12_69/ai_111852741)
The first Griffon Hovercraft to be built in the U.S. under license is now carrying people, supplies and machinery to BP Petroleum's oil production facility on North Island, six miles from Prudhoe Bay, in Alaska's Beaufort Sea.

http://thomas.loc.gov/cgi-bin/query/F?r104...104ouI14d:e920: (http://thomas.loc.gov/cgi-bin/query/F?r104:2:./temp/~r104ouI14d:e920:)
STATEMENTS ON INTRODUCED BILLS AND JOINT RESOLUTIONS (Senate - July 18, 1995)

HOVERCRAFT

The first bill would authorize the issuance of certificates of documentation with appropriate endorsements for employment in the coastwise trade of the United States for 14 hovercraft formerly owned by the U.S. Army.

These hovercraft were built for the U.S. Army by Bell Aerospace Co. in Buffalo, NY, between 1982 and 1986.

The vessels are 76 feet in length and capable of hauling 30 tons of cargo each.

After being declared surplus by the U.S. Army in 1994, the hovercraft were acquired by Champion Constructors, Inc., a subsidiary of Cook Inlet Region, Inc., of Anchorage, AK.

The hovercraft are intended to be used for transporting cargo and passengers between points in Alaska.

It is my understanding that most of the major components of the hovercraft were constructed and assembled in the United States, but that because some components were constructed in Canada, the hovercraft have been determined by the Coast Guard to be ineligible to operate in the coastwise trade of the United States.

The first bill I am introducing today would allow these vessels to be operated in the U.S. coastwise trade.

I ask unanimous consent that this bill be printed in the Record.

Quicksilver

12-23-2006, 02:33 PM

well, I guess we all agree, that we disagree with this design, hope this helped the designer ;)

for the yipster heres some more callan pics

brian eiland

12-23-2006, 03:09 PM

Not much (almost none) boating experience here, but my back ground is military:

What purpose exactly would this boat serve? Recon can be done much cheaper with UAV and electronic method.
.... and have you ever consider getting a group of boats well prepared and go pirate hunting .When the word would spread around they would be scared of hitting anybody never knowing if they where going to be faced with a pirate hunter...

...Portion of a proposal letter related to a new RIB design, and the alternative use of such a vessel in an un-manned form for pirate hunting...

"I’ve attached the full text of that letter to this cover letter. I have in mind 3 different model lengths, 12’, 16’, & 25’ for this new RIB design

The 12 & 16-foot sizes might very well have a cross-over application to the SeaOWL concept of today and the future. I believe this 'new SeaOWL' hull design could have significantly greater performance capabilities in terms of speed, rough water stability, & payload factors. And this new RIB variation could operate with or without its extra-security collar. I have already suggested that this design development could be accomplished at a very favorable cost, which could be considered even more favorable were it split between military and commercial potentials.

I’m sure you have probably considered many potential missions for your SeaOWL product, but I might suggest two more that would be applicable right NOW:
1) Low profile monitoring of the Persian Gulf and the latest Iranian torpedo & missile developments, etc.
2) A concerted effort to get some control over the ‘piracy’ situation off the coast of Yemen, Somalia, and the Malacca Straits. These SeaOWLs could operate in both a defensive monitoring posture, and an offensive one. Why not equip some of these vessels with an explosive charge that could sacrifice itself along with a few pirates who became a little too inquisitive. In time I think the situations would subside substantially if the word of mouth spread about some advanced new ‘on-the-water’ surveillance force was deployed, and that these units possessed deadly force. Certainly a lot cheaper and more efficient than trying to deploy full size Navy ships to do this job."

Couple of other references:
SeaOwl www.drs-tcs.com/brochures/seaowl.pdf
http://www.nationaldefensemagazine.o...b-no_crews.htm
http://www.usni.org/PROCEEDINGS/Articles05/Pro07cfleets.htm
http://www.smartboat.com/
http://www.nationaldefensemagazine.o...Autonomous.htm

DryFoot

12-23-2006, 03:25 PM

2) A concerted effort to get some control over the ‘piracy’ situation off the coast of Yemen, Somalia, and the Malacca Straits. These SeaOWLs could operate in both a defensive monitoring posture, and an offensive one. Why not equip some of these vessels with an explosive charge that could sacrifice itself along with a few pirates who became a little too inquisitive. In time I think the situations would subside substantially if the word of mouth spread about some advanced new ‘on-the-water’ surveillance force was deployed, and that these units possessed deadly force. Certainly a lot cheaper and more efficient than trying to deploy full size Navy ships to do this job."[/I]

Going kamikaze for a few pirates just seem like a waste here to me lol

The size of this thing should be big enough to support some small rocket launchers for the purpose of attacking pirates. Launchers for two hellfire size missiles should be possible on something like this, and while it may not sink a large vessle, the unit's position on the water surface should make a nice hole on any approaching vessel at a potentially lethal position (or, use IR guidance to target the heat source/engine on a vessel).

brian eiland

12-23-2006, 04:36 PM

Going kamikaze for a few pirates just seem like a waste here to me lol

The size of this thing should be big enough to support some small rocket launchers for the purpose of attacking pirates. Launchers for two hellfire size missiles should be possible on something like this, and while it may not sink a large vessle, the unit's position on the water surface should make a nice hole on any approaching vessel at a potentially lethal position (or, use IR guidance to target the heat source/engine on a vessel).
That's the same problem with many military projects, everything keeps growing a little bit bigger at each increment until your up to a fully crewed vessel and lots of money. Someone needs to employ the KISS principle.

..."kamikaze for just a few"....Do you realize how rumor can spread in the third world? It would only take a couple of escaping pirates to start some really big rumors about this 'robot' thing out there ready to, not only explode, but to pursue them with automatic fire. And what are they going to shoot back at...a bunch of robots that keep coming.

Still a lot cheaper than a manned platform....and totally expendable

DryFoot

12-23-2006, 05:44 PM

That's the same problem with many military projects, everything keeps growing a little bit bigger at each increment until your up to a fully crewed vessel and lots of money. Someone needs to employ the KISS principle.Except the fact that missile launchers for Predator UAVs has already been developed, so the implentation here would be to apply an the standing tech to launch similarly sized naval weapons. Also, most surveiliance platform would (or rather, should) have IR capability come standard. Not much more addiition here in my book. Besides, if nothing else, the addition of weapons like that would make the platform much more versatile (not to mention economically sound) than a kamikaze attack. Why expend an entire surveilance platform to take out a ship and leave a gap in your surveilance network? The primary mission of any platform like this should be surveilance first, and any offensive capability should be added in such a way that it adds to the mission as oppose to replacing it.

..."kamikaze for just a few"....Do you realize how rumor can spread in the third world? It would only take a couple of escaping pirates to start some really big rumors about this 'robot' thing out there ready to, not only explode, but to pursue them with automatic fire. And what are they going to shoot back at...a bunch of robots that keep coming.

Still a lot cheaper than a manned platform....and totally expendable
Just because its expendable doesn't mean its destruction should be counted on for it to perform its function. Besides, the cost-benefit counting side of my mind still can't see crashing a perfectly good surveilance vehicle to take out a (most likely) lightly armored pirate ship.

brian eiland

12-23-2006, 08:14 PM

Except the fact that missile launchers for Predator UAVs has already been developed, so the implentation here would be to apply an the standing tech to launch similarly sized naval weapons. Also, most surveiliance platform would (or rather, should) have IR capability come standard. Not much more addiition here in my book. Besides, if nothing else, the addition of weapons like that would make the platform much more versatile (not to mention economically sound) than a kamikaze attack. Why expend an entire surveilance platform to take out a ship and leave a gap in your surveilance network? The primary mission of any platform like this should be surveilance first, and any offensive capability should be added in such a way that it adds to the mission as oppose to replacing it.
As I said before, if you keep the platform simple you can 'mass produce' it at a reasonable cost. Once you add all of the missiles and launchers and fire control you increase its size, weight, and cost exponentially. So the vessel itself has to be larger, its power plant larger, and the fuel supply has to be larger, etc. I've seen this spiral before. Everyone wants to add another capability. Keep it simply and have a swarm of them. Ants, bees, and pirana are pretty effect at this.

Just because its expendable doesn't mean its destruction should be counted on for it to perform its function. Besides, the cost-benefit counting side of my mind still can't see crashing a perfectly good surveilance vehicle to take out a (most likely) lightly armored pirate ship.
I guess that means you don't believe in mines as well.

While we're at it, would you tell me how effective the new F22 fighter plane is going to be against our terrorist enemy? The've gotten soooo complicated and expensive that if they do manage to fly out of their maintence hallo, the leaders will be too worried about exposing their limited numbers to enemy fire....remember the Apache helio's in Yugoslava (http://kosovo99.tripod.com/thewar1.htm)

"In the 1999 air war over Kosovo, 24 Apache helicopters were transported to the allied base in Albania. Their arrival was anticipated by many officers and analysts as a turning point in the war. Yet, within days, two choppers crashed during training exercises. Commanders decided not to send any of them into battle; the risk of losing them to Serbian surface-to-air missiles was considered too great."

"Last year, during the Afghanistan war, seven Apaches were flown in to attack Taliban fighters as part of Operation Anaconda. They all got shot up, again by RPGs and machine-gun fire. None crashed, but five were so damaged they were declared "non-mission-capable"—in other words, unable to go back into combat without extensive repair—after the first day."

"The U.S. Army's only disastrous operation in Gulf War II (at least the only one we know about) took place on March 24, when 33 Apache helicopters were ordered to move out ahead of the 3rd Infantry Division and to attack an Iraqi Republican Guard regiment in the suburbs of Karbala. Meeting heavy fire from small arms and shoulder-mounted rocket-propelled grenades, the Apaches flew back to base, 30 of them shot up, several disablingly so. One helicopter was shot down in the encounter, and its two crewmen were taken prisoner.

After that incident, Apaches were used more cautiously—on reconnaissance missions or for firing at small groups of armored vehicles. Rarely if ever did they penetrate far beyond the front line of battle, out in front of U.S. ground troops or without the escort of fixed-wing aircraft flying far overhead."
http://www.slate.com/id/2081906/

DryFoot

12-23-2006, 10:49 PM

As I said before, if you keep the platform simple you can 'mass produce' it at a reasonable cost. Once you add all of the missiles and launchers and fire control you increase its size, weight, and cost exponentially. So the vessel itself has to be larger, its power plant larger, and the fuel supply has to be larger, etc. I've seen this spiral before. Everyone wants to add another capability. Keep it simply and have a swarm of them. Ants, bees, and pirana are pretty effect at this.

For a platform like this to be able to ID and target a vessel, all the essential function would already been fulfilled for it to be able to launch a rocket/missile. Given the smaller and unarmored nature of its intended target, you would not need anything bigger than what an infantryman would carry on his back to knock out tanks (5 lb of the complete LAW system to the 31lb of the SMAW). Add may be a lb or three to marinize it, and it's still a drop in the bucket for the carrying capacity of the SeaOwl (450lb according to the brochure) The powersupplies of these weapons are internal, and the guidance system from them can even be stripped because (I assume) any unmanned oceanic vehicles built for recon purpose would already them the electronics.

Now, these weapons are fairly useless against warships due to their short range and small warhead, but against most pirate ships? More than enough to at least maim them for less than $1500 a shot. A fraction of the sea-owl itself. I don't care how much of it you mass produced, you can't get it close to a price tage of $1500.

I guess that means you don't believe in mines as well.

On the contrary, I love them! However, if you tell me that you are going to put four wheels, engine, and enough computers to make it "smart", to use against a raccoon invasion, I'd be opposed to it in a heartbeat.

While we're at it, would you tell me how effective the new F22 fighter plane is going to be against our terrorist enemy? The've gotten soooo complicated and expensive that if they do manage to fly out of their maintence hallo, the leaders will be too worried about exposing their limited numbers to enemy fire....remember the Apache helio's in Yugoslava (http://kosovo99.tripod.com/thewar1.htm)
Being an air superiority fighter, the F22 would probably be useless against terrorist enemies. Same way an attack submarines and most other naval vessles would be useless against a terrorist with a stinger on his shoulder in the mountains of Afghanistan.

On the Apaches:

Well, that was an misuse of the apaches. Choppers should be use in direct support of ground troops, to think you can use it by itself against a large number of ground enemies and expect great results is just a bit crazy (that, or overly ambitious). These babies are built for recon, tank hunting, and close support (and they do that VERY well).

Pericles

12-24-2006, 06:46 AM

Flights or swarms of Predators, flown off tankers as they transit the Malacca Straits would be the eyes and ears against piracy. Used to investigate any suspicious vessel and capable of destroying it if required. http://en.wikipedia.org/wiki/Predator_UAV

Combined with satellite surveillance, the ability to challenge multiple vessels at long range is sensible. It is a technique taught here. http://www.kravmagauk.co.uk/instructors.html

These are the basics. You are walking alone at night on darkened streets. One, two or more persons detatch themselves from the shadows and appear to be headed in your direction. The situation is beginning to look troublesome and it would not be the best move to allow them too close. Attack, being the best form of defence, you move to engage them as you have been trained and the would be assailants are seriously incapacitated. Unfortunately, your suspicions were wrong and now you face serious charges.

To avoid such a senario, you are taught to take control of the situation and establish the true intentions of the other persons. Stop walking any further into danger, start backing away a short distance keeping them in view. Point at each person in turn ander order then to keep their distance and demand to know what they want with you. Do not warn them of your training, order them to disperse and not to come closer. Give them the opportunity to obey your orders. If they still come on, you can be confident they mean you harm so strike at once and then leave the scene.

Applying the same mindset, the Predator is capable of close range investigation with its various sensors and sound emitters, http://news.bbc.co.uk/cbbcnews/hi/sci_tech/newsid_2134000/2134383.stm

http://news.bbc.co.uk/1/hi/world/africa/4418748.stm
plus engaging the enemy with missiles before they come within range with their RPGs etc.

Why build manned stealth boats that only operate on an X & Y axis, when unmanned aerial vehicles are faster, cheaper and available in lethal numbers.

Still, you pays yer money, you takes yer choice.:D :D

Pericles

kach22i

12-24-2006, 05:08 PM

Why build manned stealth boats that only operate on an X & Y axis, when unmanned aerial vehicles are faster, cheaper and available in lethal numbers.

I've been asking myself this because the same reasoning applies to a UAV/UMV hovercraft. All I can come up with is a lower perspective is provided, true stealth from airborn radar, it "occupies ground", and may cost less if used as a buoyancy marker or underwater ROV. Combine all this with being able to operate in all nine sea states and you may have a small advantage. One thing to keep in mind is there are also UAV helicopters, ask yourslf why.

DryFoot

12-24-2006, 05:47 PM

Why build manned stealth boats that only operate on an X & Y axis, when unmanned aerial vehicles are faster, cheaper and available in lethal numbers.
It would be capable of much greater carrying capacity, which translates to longer mission time w/out refuel/resupply, range, and mission flexibility. Just off the top of my head right now.

Pericles

12-25-2006, 05:44 AM

DryFoot

12-25-2006, 09:53 AM

By flying them off tankers , which can be easily fitted with flight decks, you have surveillance, investigation and retribution. In the past Israel had armed gunships constantly flying , in order to strike whenever the opportunity arose. now UAV,s carry out the function. Israeli fighters fly to be a visible presence. The UAVs have their own tasks.

It makes sense to keep highly trained personel out of harm's way. Appropriate technology is on its way.

Pericles

The weight requirements to keep an UAV airborne is still an issue that prevents it from packing a heavy punch. The only example of an UAV that packs firepower stronger than man-portable weapon that I can think of off the top of my head is the Israeli Harpy, which is almost more cruise missle than UAV anyway.

Not to mention the limitation of progamming autonomus response in UAVs, and the inherent unreliability in having remote controlled weapon over a long range. While it may be tempting to keep trained personnel out of harms way, the modern technology still can't do that without sustaining a loss in capabilities. I doubt we have the tech to program an effective dogfighting UAV, or long range radio control device that can cut through all interference, natural or man-created.

And I'm not sure I want to have that sort of tech available, maybe it's because the SkyNet in the Terminator movies scared the beejeezus out of me.

Unmanned platform's role these days are to support manned mission, not the other way around. And I believe any military procurement and planning need to take that in mind.

kach22i

12-25-2006, 01:46 PM

I promised someone to post a few of the bookmarks I have on this topic. So here they are.

http://www.dtic.mil/dticasd/sbir/sbir032/sbir108.html

http://www.afrlhorizons.com/Briefs/Jun06/SN_H_05_02.html

http://www.engadget.com/tag/uav

brian eiland

12-26-2006, 12:54 AM

....And I'm not sure I want to have that sort of tech available, maybe it's because the SkyNet in the Terminator movies scared the beejeezus out of me.

Unmanned platform's role these days are to support manned mission, not the other way around. And I believe any military procurement and planning need to take that in mind.
I'm not sure I remember that film sequence, but I get a little concerned myself about an 'all powerful, all seeing, government', particularly after what this latest administration has promoted. I keep thing back about this statement by Eisenhower when I was growing up:

President Dwight Eisenhower, January 17, 1961
My fellow Americans, this evening I come to you with a message of leave-taking and farewell and to share a few final thoughts with you, my countrymen. We have been compelled to create a permanent armament industry of vast proportions. Three-and-a-half million men and women are directly engaged in the defense establishment. The total influence, economic, political, even spiritual, is felt in every city, every state house, every office of the federal government. We recognize the imperative need for this development, yet we must not fail to comprehend its grave implications. In the councils of government, we must guard against the acquisition of unwarranted influence, whether sought or unsought, by the military-industrial complex. The potential for the disastrous rise of misplaced power exists and will persist.

kach22i

12-26-2006, 08:46 AM

President Dwight Eisenhower, January 17, 1961
...............we must guard against the acquisition of unwarranted influence

I want in on "this" and feel that I should feel bad about it, but I want to get my project built.

If only the HoverFairy would answer my dreams.:D

brian eiland

12-26-2006, 04:40 PM

I'm not sure I remember that film sequence, but I get a little concerned myself about an 'all powerful, all seeing, government'...
Here's an example of what's coming. Imagine this technology greatly expanded and/or in the hands of a dictatorial government

Automatic License Plate Recoqnition
http://www.youtube.com/watch?v=1j_On_1zRig

kach22i

12-26-2006, 06:16 PM

Here's an example of what's coming. Imagine this technology greatly expanded and/or in the hands of a dictatorial government

Automatic License Plate Recoqnition
http://www.youtube.com/watch?v=1j_On_1zRig

Looks like a good tool to have, I better keep up with my insurance.:D

DryFoot

12-26-2006, 07:35 PM

I want in on "this" and feel that I should feel bad about it, but I want to get my project built.

If only the HoverFairy would answer my dreams.:D

Ain't that bad working for The Man. They've been footing my bill for awhile now lol.

Here's an example of what's coming. Imagine this technology greatly expanded and/or in the hands of a dictatorial governmentA truly dictatorial evil tyranical government would actually care about license plate search result and the idea of getting the right man?

FAST FRED

12-27-2006, 05:14 AM

"The potential for the disastrous rise of misplaced power exists and will persist."

The more Gov attempts to do , the bigger the chance for the "employees of last resort" to screw it up.

Still dreaming of enforced borders , and constitutional money.

FF

StianM

01-08-2007, 01:08 AM

It's not a "cat", it's sometimes called a SEC or SES standing for Surface Effect Craft or Ship. The skegs or fins on the side just keep the air in, they do not provide lift, the air pressure does that. They typically are just wide enough to get the drive systems through them. How wrong is that? It's not fins it's hulls just like it is on a normal cat. The SES skirts are there to provide lift to decrease the wetted surface. I seen this boat a couple off times and it stay afloat well abow water without it's fans running.

The US Navy last time I read is supposed to purchase some of these craft in lieu of paying some American company to develop one of their own, guess they want to save some money. How unAmerican.:D

The MTB's they used in Vietnam was also off norwegian design in norway called tjeld class MTB fitted with british Napier Deltic engines.

The americans bought penguin rockets from norway for years now.

http://www.hoverclubofamerica.org/forum/index.php?showtopic=460&hl=Skjold

Intresting thread:)

kach22i

01-08-2007, 09:22 AM

How wrong is that? It's not fins it's hulls just like it is on a normal cat. The SES skirts are there to provide lift to decrease the wetted surface. I seen this boat a couple off times and it stay afloat well abow water without it's fans running.

I take the term hull to be the part of the watercraft which floats. In a SES there is a hull and it has side extentions which are designed to keep the pressurize air "captured". The SES will never float on the side extentions alone therefore I don't think of them the same as I would a catamaran as the function is completely different even though their is a resemblance.

The MTB's they used in Vietnam was also off norwegian design in norway called tjeld class MTB fitted with british Napier Deltic engines.

The ones which changed history, should I thank you?:cool:

PTF
http://www.hnsa.org/ships/ptf3.htm
First in the series of U.S. Navy NASTY Class Patrol Torpedo Fast boats, PTF 3 marked the return of the wooden PT Boats to the U.S. Navy. Commissioned in 1963, PTF 3 was sent to South-east Asia in the fall of 1963 as a "Spook Boat" operated by MAC V SOG, Maritime Special Ops, PTF 3 along with 5 other PTF boats began raids against North Vietnam by attacking shore installations and inserting special operations teams.

It was during a series of raids from 31 July to 4 August 1964 on Hon Mei Island in North Vietnam that the North Vietnamese counter attacked the PTF Boats with their torpedo boats, chasing the PTF Boats away from the coast and into the path of two U.S. Navy Destroyers the U.S.S. Maddox and the U.S.S. Turner Joy. The ensueing naval battle is known to history as the Tonkin Gulf Incident.

Within a week President Lyndon B. Johnson presented the Incident to the American People as an unprovoked attack of U.S. Naval Ships on the High Seas. The Congress of the United States passed the Tonkin Gulf Resolution, authorizing President Johnson to escalate, what had been a civil war in Southeast Asia into the Vietnam War of 1964-1975.

http://www.hnsa.org/ships/img/ptf3a.jpg

Another link:
http://www.ptfnasty.com/ptfnorway.htm
To whom it may concern:

I am researching the history of US Navy PT boats (motor torpedo boats)
after World War Two. A group of 80 foot long Elco class PT boats was
sent to Norway in the early 1950s and used by the Royal Norwegian Navy
into the 1960s. Also, two firms built a total of 14 Tjeld/Nasty class
boats (known as PTFs in the US Navy) for service in Viet Nam. Two of
those boats were shipped directly to the United States (US Navy hull
numbers PTF-3 and PTF-4). The rest were transported to Subic Bay Naval
Base in the Philippines for modifications and then sent to Da Nang, Viet
Nam for duty. There might be some information of interest to you at the
website www.ptfnasty.com.

I am interested in obtaining pictures of the Elco class PT boats in the
Royal Norwegian Navy and Nasty/Tjeld class boats under construction,
being launched or tested for the US Navy and service in Viet Nam. Is
there someone specific I should communicate with? Do I have to come to
the museum or can I select photos from the USA?

Thank you for your time and any assistance.

Chip Marshall
Silver Spring, Maryland USA

StianM

01-08-2007, 11:31 PM

I take the term hull to be the part of the watercraft which floats. In a SES there is a hull and it has side extentions which are designed to keep the pressurize air "captured". The SES will never float on the side extentions alone therefore I don't think of them the same as I would a catamaran as the function is completely different even though their is a resemblance.

Then how do they float when the fans is stoped? or when they change the skirts? They tear 2cm a hour at 50knot last time I heard:confused:
If you removed the skirts it would become just another cat maybe doing only 45-50 instead off 60knot.

The ones which changed history, should I thank you?:cool:

I don't think annything the americans brought into vietnam changed mutch except a extra grave now and then.

In addition, Deltic diesels served in MTBs and PT Boats built for other navies; particularly notable being the Norwegian built Tjeld (Nasty) class, which were also sold to Germany, Greece, and even the United States Navy. PTF Nasty class boats served in the Vietnam War, largely for covert operations.

http://www.wis.co.uk/justin/deltic-engine.html

kach22i

01-09-2007, 10:28 AM

Then how do they float when the fans is stoped?
All hovercraft and SES craft can float on their hulls (not sidewalls). They either have foam filled hulls or air tight chambers for this purpose. This can be a problem in heavy seas should they lose lift power. In heavy seas they may become not much more than a top heavy raft being tossed by the waves. Not a good situation because they can capsize then - just a warning.

I guess I need a picture to help explain the message here, it always helps me so indulge me.

A Comparison of Power Catamaran Hull Types
RePrinted from the Spring 2000 Issue of Power Multihulls Magazine
by Prof. Jacob van Renen van Niekerk
http://www.multihullsmag.com/magazine/articles/cathulls/cat%20hulls.htm
Characteristics of Type-F
F. SES (solid side skirt) hovercraft with low tunnel and skirts at bow and stern.

The solid side skirt hovercraft is not considered a catamaran by many, but it does have two long, slim sponsons almost like Type-E, but with the addition of flexible skirts fore and aft. The skirts are there to contain the cushion – air that is pumped into the big empty space between the sponsons, skirts and tunnel roof to lift the craft up to where it has minimal draft and wetted area. The SES was developed by people who were unhappy with the normal hovercraft where air-propulsion is needed. They thought that these slim sponsons would allow populsion by waterjet or propeller and so make it more efficient. Another handicap of a pure hovercraft is its susceptibility to cross winds and its consequent need to wheathercock to counter them. So don’t be surprised if you see one traveling almost sideways to go along a certain course. Having slim hulls in the water helps offset this to a considerable extent.

But it is costly to build and maintain and its ride characteristics are not acceptable to many. It is load-sensitive and the CG has to be dead right. The ride is wet and becomes hard when the waves hit the relatively low tunnel. On the upside, it is capable of good speeds in calm conditions. As an afterthought, it is probably unfair to compare it with normal cats.

http://www.multihullsmag.com/magazine/articles/cathulls/F1.jpg

NOTE: Click the link above and read about the differences, the pictures are worth a thousand words.

StianM, because you made me do an image search I found some new stuff, so it was not a waste of time. Below is what I found.

Hull is where the lift fans empty, not the side sponsons/sidewalls.
http://www.stepi.re.kr/researchpub/abstract/ABAA-1996-022-006.HTM
http://www.stepi.re.kr/researchpub/abstract/IMAGE/ABAA-1996-022-0034-01.JPG

More images:
http://www.dyferry.com/usefulinfo_type_2.asp
http://www.dyferry.com/usefulinfo/images/img_ship2_13.gif

More (hull is upper part with fans):
http://www.ivt.ntnu.no/imt/courses/tmr4217/introduction/air_cushion_support.html
http://www.ivt.ntnu.no/imt/courses/tmr4217/introduction/air_cushion_support_html_7043e96a.gif

SES - nice visual of many types:
http://www.australianhovercraft.com/design_effects.htm

Sidewall SES (typical)
http://www.australianhovercraft.com/design_effects.htm
may also be propelled by water jets
http://www.australianhovercraft.com/images/effects_hull_sidewall.gif

Aircat, with wide buoyant hulls .........not a typical SES - might be sole example. Looks to be similar to what you thought all SES were like based on their outside look. The side sponsons/sidewalls on this craft do provide some lift, although I doubt it's more than 15% of overall.
http://www.australianhovercraft.com/design_effects.htm
http://www.australianhovercraft.com/images/effects_SES_wide_buoyant_hulls.gif

StianM

01-09-2007, 11:47 PM

I'm not aruing the priniple, but the error is your statement.

Your statement is that the boat float on the aircoushin alone.

kach22i

01-10-2007, 10:40 AM

I'm not aruing the priniple, but the error is your statement.

Your statement is that the boat float on the aircoushin alone.

More cushion, less pushing.:D

jehardiman

01-10-2007, 10:57 AM

kach22i

01-10-2007, 11:03 AM

I think if you ignore any critical aspect of the sidewalls when designing a SES you will fail and fail quickly. If we list all the things they do, most will be similar to boats as they come in contact with the water. So you will have drag, just a lot less of it. You will have lift, just a lot less of it.

In principal theory the SES does not derive lift from the sidewalls, in actual application this will vary depending on the designers intent. You can design the sidewalls so they only do their job (of sealing in air) within a very narrow definition or expand it to 15% lift of an "AirCat".

The only error I see is not being open minded to the basic concept of SES design and getting caught up on a few percent which if exists at all may only be intended to aid in getting over "hump speed" and or ballast to help level out the craft with load. The best sidewall designs from what I've read are intended to be as neutral as possible. In addition a useful reserve lift capacity is sought after for heavy weather operation as the drag from waves may pull you down with them, and falling seas can leave part of the sidewall open to the atmosphere allowing vast amounts of lift air to escape rapidly.

Having positive buoyancy in the sidewalls may be a nice thing, but certainly not a basic requirement for operation. You would not want too much lift generated at speed from the sidewalls because if it is not easily controled you could lift out of the water causing rapid cushion loss which would result in plow-in and injury to passengers. It's all about balance and control, each designer and engineer has to deal with the same physical world, they might take different paths to get there. And that is okay with me.

StianM

01-16-2007, 11:49 PM

BTScow

01-17-2007, 08:39 AM

Alex,
Totally cool - very envious. I would love to be designing craft for the US military - big guns, fast, durable boats, close in support of special forces - what more could a guy ask for.

kach22i

01-17-2007, 10:37 AM

I wouls like to see how your theory boat would do the moment it hit drift wood with sharp edges riping the skirts open.

Would sink like a stone right?

Sound like you try to make a ses boat sound like a howercraft where the side coushins are replaced by fins.:rolleyes:
1. Drift wood is mostly submerged and often smooth out, what makes it so dangerous is that you don't see it until you are on top of it or you hear a loud bang.

2. The bow and stern of a SES or hovercraft skirt most likely would go over such a thing without damage, if torn the fingers can be replaced at base.

3. The sidewalls of an SES hitting driftwood would have the same possibility of damage as a flying boat or boat hull, remember that the sidewalls have much less frontal area.

4. Don't confuse hydrofoils with hovercraft, SES or high speed catmarans.

5. A SES in very simple terms is a hovercraft with side skirts replaced by sidewalls.

6. I have had large long sticks/tree branches sticking out of both finger skirts and bag skirts. I did not even know the stuff was stuck in there until I got on shore and did an inspection. Pull it out, patch the hole and all is good as new.

7. Like many chambered or foam filled boat hulls, most hovercraft can be cut in half and still float.

8. Coming off cushion just puts you in displacement mode (like a boat), I've done this to do some fishing.

Skirt wear:
http://www.hovercraft-museum.org/swift1.html
http://www.hovercraft-museum.org/images/sw34.jpg

kach22i

01-17-2007, 10:43 AM

Alex,
Totally cool - very envious. I would love to be designing craft for the US military - big guns, fast, durable boats, close in support of special forces - what more could a guy ask for.
Our "Alex" has one post, I think he owes us for pulling our legs on this one.

A quick admission of guilt and all will be forgiven, save the fertilizer for the farm boys.

Alex Alequin

02-02-2007, 12:54 PM

Our "Alex" has one post, I think he owes us for pulling our legs on this one.

A quick admission of guilt and all will be forgiven, save the fertilizer for the farm boys.

To be honest, with the holidays and the new year happeneing after my initial post i totally forgot to come back and reply to all your questions. -which by the way i do appreciate all the responses and concerns surrounding this concept.

One thing i feel i do have to make clear though. While working on this project the theme was "protect our borders". this vehicle was designed to be a sitting duck and intercept ie drug trafficers off the coast- immigrants beiing illegally imported and terrorists alike. that was the idea. i was given a layout and options for engines (some more feasible than others) and was also given the freedom to explore any concept that revolved around our theme no matter how wreckless and unfeasible it may seem -hence the sketches posted. those skectches inspired the next phase of concepts and established a direction which go inline with all your concerns about stealth capability.

this boat would most likely be seen off the coast of florida with emphasis on cuban waters in the near future.

it might not make sense as to why anyone would invest in such a project but to be frank theres alote to say for unsecured borders when it come to the water.

anyways, i hope i shed some light onto your concerns i'll post up later in the week about some comments i read that i felt were good concerns. let me just reiterate this last point before i go. when money is no object, and people will do anything to be safe or atleast feel at peace when they go to sleep at night- everything is posible. nothing is unfeasible and theres an answer for everything. i learned that while doing this project.

thats all i can really say without saying everything but when the website goes on i'll be sure and post it.

best reguards;
"alex"

kach22i

02-02-2007, 01:22 PM

sitting duck............ those skectches inspired the next phase of concepts and established a direction which go inline with all your concerns about stealth capability.

A ship designed to intimidate all those who dare to pass................just gave me an idea.

http://www.partytimeleisure.co.uk/
http://www.partytimeleisure.co.uk/galleon2.jpg

.........and it's cheap.:D

All kidding aside, please post when your are ready.:)

Alex Alequin

02-02-2007, 01:33 PM

ready for what?

kach22i

02-02-2007, 01:35 PM

thats all i can really say without saying everything but when the website goes on i'll be sure and post it.

best reguards;
"alex"..........................ready for what?

Your website, post a link to your website when you are ready.

Considering the trooper going on trial for shooting at illegals who tried to run him over, I would consider putting a heat ray on the boat.

US military unveils heat-ray gun
http://news.bbc.co.uk/2/hi/americas/6297149.stm
Called the Active Denial System, it projects an invisible high energy beam that produces a sudden burning feeling.

safewalrus

02-02-2007, 02:31 PM

Alex
I like your spelling of "wreckless" you seem to have got it in one!

BT Scow
Designing them for REAL special forces maybe? not border guards! anybodies!

wellmer

02-02-2007, 08:55 PM

Hello Alex,

Best way to go stealth on water is to go below surface.

A submarine is completly OFF radar and if you make it quiet it is OFF sonar too - jet turbo whatever - engines are not a great way to stay undetected... so this is what seals are doing right now - aproaching in subs - no need for a stealth surface ship ...

My project : Submarine Yachts
http://imulead.com/tolimared/submarine/aa.gif
Built one back in 1996
http://imulead.com/tolimared/submarine/ac.jpg
Worked Perfectly - Submarine Yachting is possible -
http://imulead.com/tolimared/submarine/dh.jpg
Submarine yacht, personal submarine
http://imulead.com/tolimared/submarine/da.jpg
personal submarine yacht, weekend submarine on mooring
http://imulead.com/tolimared/submarine/ad.jpg

See the proyect - at:
http://tolimared.com/submarine

arnonrod

02-03-2007, 12:25 AM

Hi Alex,

have you approached anybody from Defence? They always look for different things that can be of immediate use.

BMcF

03-07-2007, 01:24 PM

An interesting place for me to stick my first post. I had a bit do with the KNM Skjold design..and trials..and those of many SES prior to that.

First, the Skjold is not stealthy in 'run away' mode..the GT exhausts are huge and stick right out of the transom. Her stealth characteristics are focused on approaching a potential adversary..the assumption being her anit-ship missiles will make sneaking back away from said target unnecessary.

All SES' built since the late 70s are what are termed 'fat sidehull' designs..in Norway, they even started calling them ACCs - air cushioned catmarans. The very early (most USN prototype models) SES concepts did have very thin sidewalls instead of 'real' hulls and were typically low L/B designs They proved impractical for reasons too numerous to go in to here.

The state of art in current SES designs - Skjold being a prime example, but there are others - is to not exceed a cushion lift fraction in flat calm water of 80%..down to as low as 60% in rough water. With 40% of the vessel supported by its cat hulls, hull hydrodynamics do play a significant role in the seakeeping of the ships. Cushion L/B ratios are also much higher 'nowadays'; the high L/B designs with fat sidehulls were found to have much lower hump drag and better resistance in the region just beyond the drag hump, at the expense of increased resistance in the 'very high' speed regimes that the orignal short L/B boats were intended for (the SES-100B..at 95 tons displacement..still holds, I belive, the record for achieving the highest speed at the displacement of any ship built . 93 knots IIRC.

Skjold spent some time here in the states on demonstrations and USN evaluations (as can be seen in pictures and text on the vessel's web site log) but the USN could not quite figure out what to do with the information that they gleaned from testing her.

Here are a few pics of other SES for your viewing enjoyment..to try and spice up my otherwise boring dissertation:D

The Swedish Navy's Stealth SES prototype..
http://www.islandengineering.com/images/ses_mu2.jpg

The Norwegian SES mine-countermeasure vessels..
http://www.islandengineering.com/images/ses_mu3.jpg

A 50-knot 400-pax ferry we designed..built in Korea

http://www.islandengineering.com/images/democracy2.jpg

kach22i

03-07-2007, 01:44 PM

Nice first post.:)

The US Navy back in the early1970's was promoting a 100 knot Navy, I guess that's why they used such thin sidewalls.

I did not know the KNM Skjold design was considered a 'fat sidehull' design....................answers an older part of our discussion.

BMcF, do you have any idea of the Skjold cost/price?

What were the prices of the VT EPS/ABS M10 and Griffon 8000 hovercraft as a comparision?

BMcF

03-07-2007, 02:12 PM

Thanks for the prop. ;) I've been a 'Jesus Boat' designer for over 20 years, involved in most all that have been built in that period..and far too many that were not built.:mad:

IIRC, the 47m Skjold cost about 73 million USD to build back in the late 90s. But that was entirely without combat systems of any kind..but with (a lot of) non-recurring engineering costs..etc. So..I have no idea what the cost of the 5 series vessels now being assembled might be, espeically when including the 'all-up cost' with all combat systems in place. Skjold herself has been chopped to pieces and rebuilt to incorporate all the engineering changes arising from her trials period; major ones include changing from Allison GT + Diesel propulsion to a 'COGAG' powerplant using PW ST18 and ST40 turbines in tandem power units.

VT's M10 hovercraft cost?..no idea. In fact, being SES designers and the suppliers of some of the specialized SES/ACV equipment 'only', we seldom have insight in to total project cost numbers. I can tell you that the Korean passenger 40m SES shown in my pic earlier cost about 12 million US to build.

To undo my hijack a wee bit..to answer the original question posed in this thread, there is keen interest in some US naval communities (SOCOM for example) in relatively small, very high-speed stealthy vessels. The problem is that the requirements and CONOPS for same seem to be impossible to develop such that acceptance by a critical mass of 'end-users' gets on board with any one concept.

kach22i

03-07-2007, 03:28 PM

CONOPS ............

I start getting excited when acronyms are used.........ONR, PEO, USSOCOM, the list goes on.

I'm sold, please start a tread on some of your work BMcF so you don't have to worry about hi-jacking a thread from a guy with just a couple of posts.:)

'Jesus Boat' ............walks on water?

BMcF

03-07-2007, 03:42 PM

Acronyms can be challenging and 'fun'..we are working on a project for USN that is only 4 or 5 years along and its already on its fourth acronym..LCAC-H, SSSC, SSC, and now JMAC.:rolleyes:

I've been spending most of my time reading back through a lot of the posts on here and probably should continue to do so (I found your own earlier post of a pic of 'Smyge' and the sad photos of an SES that was near and dear to my heart being raped in to a configuration with a large lifting body under instead..:mad: )

My specialty is actually stabilization/ride control/ motion control or whatever terms suits yr fancy these days. SWATHs, SES, cats, monohulls and hydrofoils (sorry..no WIGS yet) I have not seen a lot on here about vessel motion control..perhaps I can rectify that.

BMcF

03-07-2007, 03:46 PM

'Jesus Boat' ............walks on water?

LOL..you got it. Coined by an old friend (now deceased) who was one of the old guard at Bell back in the heady days of 100-knot SES's, 80-knot Jeff-B hovercraft, 2K-SESs... Good guess..:D

kach22i

03-07-2007, 04:47 PM

Acronyms can be challenging and 'fun'..we are working on a project for USN that is only 4 or 5 years along and its already on its fourth acronym..LCAC-H, SSSC, SSC, and now JMAC.:rolleyes:
.

CDI right?

http://www.cdi-gs.com/index.shtm

You can PM me, I can't PM you as you have it disabled.

I like the low profile thruster, better than the one in my sketchbook.

BMcF

03-07-2007, 04:53 PM

No..but good guess! I'm with Island Engineering (www.islandengineering.com) and , before that, Maritime Dynamics. CDI (or that particular part of CDI which I still call Band-Lavis, or BLA, since I'm old ;) ) is populated by quite a few long-time friends/colleagues and we do collaborate on some projects. In fact, we were both involved in the Norwegian MCMV SES program too.

BMcF

03-07-2007, 04:58 PM

.

I like the low profile thruster, better than the one in my sketchbook.

Finnish Fontier Guard ACV..first ACV with stealth requirements, hence the cute low-profile thruster. Only one was built and by my friends in southern Norway who built - and are now building more of - the Skjold and the MCMVs.

This thread is hopelessly hijacked..I apologize in advance for bad forum manners. I'll go start my own somewhere.:)

RANCHI OTTO

03-07-2007, 05:24 PM

No problem BMcF...very interesting (for me...)!

kach22i

03-07-2007, 05:30 PM

This thread is hopelessly hijacked..I apologize in advance for bad forum manners. I'll go start my own somewhere.:)

I'm sure the boat guys would enjoy a thread on the MM56CX, that cool tri-hull.

As seen here:
http://www.islandengineering.com/
(click NEWS)

And seen in this Gallery:
http://www.boatdesign.net/gallery/showgallery.php/cat/500/ppuser/13291

http://www.islandengineering.com/images/Dscn1362Mod.jpg
http://www.islandengineering.com/images/Flight1.jpg

I like anything which may be termed a "Jesus Boat".:)

BMcF

03-07-2007, 05:35 PM

LOL..I see my partner has posted a few of our pics here already (that's me flying the foil-tri in those pics:D ). Good on 'im..he's within stone-throwing distance of where I sit here and type. He told me about this forum some time ago. I guess I'm not just old..I'm slow too.:D

First thing I should do is search his posts and see what he's already bored everyone with...

RANCHI OTTO

03-08-2007, 09:43 AM

Nice...beautiful...interesting.....huge...etc.

kach22i

03-08-2007, 10:23 AM

Nice...beautiful...interesting.....huge...etc.

I think it's the testing scale model for a much larger project.

brian eiland

03-08-2007, 10:30 AM

Thanks for the prop. ;) I've been a 'Jesus Boat' designer for over 20 years, involved in most all that have been built in that period..and far too many that were not built.:mad:
I've talked briefly with one of your working mates Rick Loheed about a RIB project I had in mind.

But, what I'm interested in here is hearing your comments on this 'ridiculous' design and waste of money in my opinion:
M-Hull, M hull, M Ship
http://boatdesign.net/forums/showthread.php?t=5687 (http://boatdesign.net/forums/showthread.php?t=5687)

(probably best to add them to that other threaded discussion)

(BTW I live right up in DC now, but spent quite a number of years in the boat business down there in Annapolis)

BMcF

03-08-2007, 11:16 AM

I think it's the testing scale model for a much larger project.

The tri-foiler was indeed a 1/4-scale model of a 56m high-speed ferry. The performance results were rather remarkable in the areas of seakeeping (the human factors/habitability/comfort part of seakeeping) and speed v. powering results. A 26m pax-only proptoype is *trying* to get built in Norway at this time..subject to the vagaries of government funding/support for the project.

Still have the test craft..on the hard awaiting her fate. We will either repower with a single diesel and twin IO drives (replacing the gasoline 460 and twin waterjets) or render her to beer cans. The flight control system and foils are still intact and in good shape and the hull is still perfectly sound..hate to break her up but that is usually the fate of all 'models'.:rolleyes:

BMcF

03-08-2007, 11:25 AM

I've talked briefly with one of your working mates Rick Loheed about a RIB project I had in mind.

But, what I'm interested in here is hearing your comments on this 'ridiculous' design and waste of money in my opinion:
M-Hull, M hull, M Ship
http://boatdesign.net/forums/showthread.php?t=5687 (http://boatdesign.net/forums/showthread.php?t=5687)

(probably best to add them to that other threaded discussion)

(BTW I live right up in DC now, but spent quite a number of years in the boat business down there in Annapolis)

Hmmm...I would probably be well advised to not start throwing out my opinions, personal or professional, about such as 'M-Hull', when I'm only a 'newbie' on this forum. There were some interesting comments in that thread about other vessel types that are near and dear..such as Mr. Clifford's catamaran creations that required so many of our active stabilization solutions;) Oh the stories I could tell..but most often shouldn't.

brian eiland

03-08-2007, 11:57 AM

I'm sure the boat guys would enjoy a thread on the MM56CX, that cool tri-hull.
As seen here:
http://www.islandengineering.com/
(click NEWS)
I like anything which may be termed a "Jesus Boat".:)
I assume you are familar with Dick Newick's tri-hull powerboat
http://www.yachtforums.com/forums/16142-post55.html (http://www.yachtforums.com/forums/16142-post55.html)

...or Peter Payne's work down there on Chesapeake Bay, Sea Knife
http://www.yachtforums.com/forums/16010-post47.html (http://www.yachtforums.com/forums/16010-post47.html)
http://boatdesign.net/forums/showpost.php?p=81761&postcount=8 (http://boatdesign.net/forums/showpost.php?p=81761&postcount=8)

In fact you might find this whole subject thread interesting
http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner.html (http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner.html)

BMcF

03-08-2007, 12:20 PM

Quite familiar with all of the above. Close friend has the scars to show for his encounter with the Bladerunner's 'uusual' stability performance during one particular high-speed turning demonstration. Peter's work?...well suffice to say, he was not lacking in innovative concepts. His Wavestrider, I believe it was called, was REALLY interesting from the operator's viewpoint.;)

Note our MM56CX trimaran is not a trimaran....really. It is a super-slender monohull when at operating design speed, with 75-80% of the displacement on the foils and only a portion of the center hull in contact with the or below the water surface. The amas are well clear of the water surface.

brian eiland

03-08-2007, 01:54 PM

Verytricky

03-08-2007, 02:21 PM

Is this the powerboat - Bladerunner as in the thing called Bladerunner built in the UK?

A truly horrid thing. And unfortunately I own one....

BMcF

03-08-2007, 02:28 PM

Is this the powerboat - Bladerunner as in the thing called Bladerunner built in the UK?

A truly horrid thing. And unfortunately I own one....

ICE Marine's craft is the one I was referring to..yes, its a UK group. I met the principals when they visited our facility for a demonstration of our foil-assisted trimaran..back in about 2002, when they first hit the scene, so to speak.

I've seen nothing in way of any hard test data on their boats, but know a little about how well they manage high-speed turns if you push the envelope a bit too much. But you can also blame the driver I suppose.

Verytricky

03-08-2007, 02:51 PM

ICE Marine's craft is the one I was referring to..yes, its a UK group. I met the principals when they visited our facility for a demonstration of our foil-assisted trimaran..back in about 2002, when they first hit the scene, so to speak.

I've seen nothing in way of any hard test data on their boats, but know a little about how well they manage high-speed turns if you push the envelope a bit too much. But you can also blame the driver I suppose.

OK, year 1999 first one built.
I own the first commercially offered for sale one, powered by 2x300 promax outboards.
Blame the driver - going to smack you one!!!:P

First off, really very very very stable in a flat sea, high speed flat running, excellent. But, and a huge but here, they are totally useless in a big sea, any thing over say 3 foot.

First off, if you hit the waves head on, they crash over the boat, dipping the nose into the sea, no amount of attitude adjustment from the engine will work, as you basically have no control over the attitude of the boat.

Second, if you hit waves from anything from say 15 degrees to 70 degrees, the one 'outer leg' dips into the trouph, whist the other is on a peak of a wave and this tries to throw the boat over. Occasionally a wave will 'bottom out' the lift on one side, and because ( unlike a cat) it is a very short section, it dips, bites water and tries to spin. Very bad at anything faster than 30 mph..

It also tends to burry the nose in a corner, again because you cant 'lift' the nose.

I do believe I am a good driver, and I have a world offshore speed record and a british national speed record to my name, as well as regularly winning offshore races. As such, I can recognise a boat that is inherently unsafe to drive in anything exceept the most perfect flat calm windless conditions.

As far as I know, no one who was stupid enough to buy one ( yes, laugh ) actually uses it. I have seen several for sale ( as is mine on sale ! ) and they are going for around 20% of their original purchase price, and still not selling!

The 'race version' was up for sale for 4 years, it was bought for around £70k, refitted, and was back on sale in under 1 month. Currently you can buy it for £40k, fully refitted, new electronics etc - the new radar, nav systems etc are prolly worth over £15k by themselves, almost woth buying just to scrap it for parts!!!

None of the 8 or so currently for sale have more than 60 hours run time! Because they scare the sh.... out of the owners who then discover that no one really wants to buy them.

Lorne Campbell has been designing three pointers for years. They have raced with great success for one or two races - then for no real aparent reason have dumped the crew. I have seen one cartwheel around a turn bouy in flat racing conditions. They are simply not a good idea.

Having said that, anyone wanting to buy a nice red Bladerunner, £35k for the boat, all kited and ready to go. £4k will buy you the road trailer that goes with it.....

kach22i

03-08-2007, 02:56 PM

That's a real shame, they are such pretty boats..............and don't look very different from other exotic designs I've seen in this forum.

http://www.icemarine.com/spec/51_spec.htm#

http://www.travelizmo.com/archives/cat_sport_boats.html
http://www.travelizmo.com/archives/bladerunner%2051-high-performance-powerboats-sport-boats.jpg

The C of G looks way forward in this image.
http://www.icemarine.com/profile2.htm
http://www.icemarine.com/images/profile_02l.jpghttp://www.icemarine.com/images/profile_02r.jpg

BMcF

03-08-2007, 03:17 PM

OK, year 1999 first one built.
I own the first commercially offered for sale one, powered by 2x300 promax outboards.
Blame the driver - going to smack you one!!!:P

....

Uh oh..on here less than 1 week and I've already invited threats of physical violence against my person. I expect the ban wagon will be pulling up shortly..:D

Actually..I was not meaning to impugne YOUR driving skills at all..I was referring to the little incident where the barrel-rolling of a Bladerunner at high speed left a rather nasty knot on a friend's head that requiered a fair number of stitches. Good thing for him that chicks dig scars, eh?

Miraculously, considering the speed involved and the violence of the sudden roll-over, no one was killed or even seriously injured in the mishap.

I've been in the 'funny boat' business long enough that I've seen a lot of gimmickry come and go. Sorry to hear about your experience..and I think I'll have to pass on your generous offer for sale. My 16' '72 Donzi causes me enough trouble - making good use of my vast experience in small craft design, I wisely installed a very conservative 486 dyno-proven HP in the little 'skiff'.
http://www.supermotors.net/getfile/407119/fullsize/eekjawdrop.gif

Verytricky

03-09-2007, 06:15 AM

Uh oh..on here less than 1 week and I've already invited threats of physical violence against my person. I expect the ban wagon will be pulling up shortly..:D

I dont think they have a BAN button. I am still here after all these years, so this forum most definately does not have one!:D

brian eiland

03-09-2007, 10:15 AM

OK, year 1999 first one built.
I own the first commercially offered for sale one, powered by 2x300 promax outboards.
Blame the driver - going to smack you one!!!:P

First off, really very very very stable in a flat sea, high speed flat running, excellent. But, and a huge but here, they are totally useless in a big sea, any thing over say 3 foot.

First off, if you hit the waves head on, they crash over the boat, dipping the nose into the sea, no amount of attitude adjustment from the engine will work, as you basically have no control over the attitude of the boat.

Second, if you hit waves from anything from say 15 degrees to 70 degrees, the one 'outer leg' dips into the trouph, whist the other is on a peak of a wave and this tries to throw the boat over. Occasionally a wave will 'bottom out' the lift on one side, and because ( unlike a cat) it is a very short section, it dips, bites water and tries to spin. Very bad at anything faster than 30 mph..

It also tends to burry the nose in a corner, again because you cant 'lift' the nose.

I do believe I am a good driver, and I have a world offshore speed record and a british national speed record to my name, as well as regularly winning offshore races. As such, I can recognise a boat that is inherently unsafe to drive in anything exceept the most perfect flat calm windless conditions.

As far as I know, no one who was stupid enough to buy one ( yes, laugh ) actually uses it. I have seen several for sale ( as is mine on sale ! ) and they are going for around 20% of their original purchase price, and still not selling!

The 'race version' was up for sale for 4 years, it was bought for around £70k, refitted, and was back on sale in under 1 month. Currently you can buy it for £40k, fully refitted, new electronics etc - the new radar, nav systems etc are prolly worth over £15k by themselves, almost woth buying just to scrap it for parts!!!

None of the 8 or so currently for sale have more than 60 hours run time! Because they scare the sh.... out of the owners who then discover that no one really wants to buy them.

Lorne Campbell has been designing three pointers for years. They have raced with great success for one or two races - then for no real aparent reason have dumped the crew. I have seen one cartwheel around a turn bouy in flat racing conditions. They are simply not a good idea.

Having said that, anyone wanting to buy a nice red Bladerunner, £35k for the boat, all kited and ready to go. £4k will buy you the road trailer that goes with it.....
Hello Verytricky,
I found you analysis very interesting and have some additional qestions for you in the future. At the moment I'm pretty busy getting my new DynaRig motorsailer up online.

I looked back thru a few of your postings and found this one that appears to be an idea you have for an air entrapment hull design
Retrofit Turbine Engine to Powerboat
http://www.boatdesign.net/forums/showthread.php?t=9011 (http://www.boatdesign.net/forums/showthread.php?t=9011)

Doesn't this discussion conflict with you dislike of the Bladerunner hull form??

Yes.

It has a long thin center hull ( 32 foot ) with two 'tunnels' for air entrapment. The outer 'hulls' are really blade like runners, and are about 1/3 the length of the hull.

She rides completely flat. You can not get the bow 'up' - she is always flay to the sea.

And at the end of this tread I found I had contributed to it as well,
Turbine Powered Rib
http://www.boatdesign.net/forums/showpost.php?p=77683&postcount=22 (http://www.boatdesign.net/forums/showpost.php?p=77683&postcount=22)
The thread died there and no one else contributed??

And finally I was going to ask if you had ever contributed your views of this design to that subject thread at Yachtforums,
Trimarans and the Bladerunner
http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner-7.html (http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner-7.html)
..but I just looked there and found you did recently make a posting. I think you should repeat that posting you made here and see what reaction you get on the other site??...should be interesting

Great learning on these forums...information sharing!!

Thanks and regards

Verytricky

03-11-2007, 06:55 AM

I found you analysis very interesting and have some additional qestions for you in the future.

Anytime. If I can offer information that is useful, I hope to do so.

I looked back thru a few of your postings and found this one that appears to be an idea you have for an air entrapment hull design
Retrofit Turbine Engine to Powerboat
http://www.boatdesign.net/forums/showthread.php?t=9011 (http://www.boatdesign.net/forums/showthread.php?t=9011)

Doesn't this discussion conflict with you dislike of the Bladerunner hull form??

You will notice I have dropped the thought of adding more power to the boat. My initial reasoning was that I was told that the engines I had fitted, the 300 promax were limiting the ability of the boat to 'get air' correctly, and the race version with more power resolved all the issues I was having. So I thought to add a chunk of extra power and lighten the boat would solve the issues.:idea:

( see - although it handles like a dog in any sort of sea that is not perfect calm, it is a very sexy looking boat, and I wanted it to work. ):!:

Unfortunately, I went out in the race version, and although lighter by a third, and more powerful by about 20% it still has exactly the same characteristics.:mad:

So I 'moved on'...

I figured I would spend a lot of money on something that was unfixable. Basically I have a boat that is capable of 80mph, but which you can only safely drive at 55mph. I have moved on to the Occe Manefeld 'Bat Boats' and find them to be very delightful. They do what they are supposed to do, and in a very ( booringly ? ) predictable way. They warn you when you are pushing the boundary, and fail in a pedictable manner, so you can recover from your errors. I like that. The boat design makes me look like a very good driver!:)

The Bladerunner isnt' - It will trumble along and them without any warning try kill you. No predictability ( I suppose you can mathematically predict why it does what it does, but that is little help when you are at sea! )

I suppose one day I may re-look the boat as a project. Perhaps install a deep running drive like a DPX, and a lightweight V8 650hp engine - probably blown. Then try fix the 'attitude' by playing with spray rails etc.

( Another issue is that when the stern correctly raises itself on the cussion of air, the bow digs itself deeper into the water - the COG appears to be at about the front windscreen. If not the COG, then definately the pivot point. Way too far forward for comfortable driving. Its asking too much of the design for the bow to lift with the stern, but it needs to do this to be stable. Possibly some changes to the spray rails - and something like the sunseeker XS anti stuff nose ( buzzi design ) or even a second - smaller bow spray deflector to kick up the nose at speed? Something just out of the water line at cruising speed, yet forced into the water when the stern lifts and the boat pivots, to help the bow up? Loads of thoughts - possibly one day a reality? )

Or alternately, ship the boat inland and use it as a Lake Boat - No wave action - no issues.

Lenny

03-16-2007, 09:38 AM

My 16' '72 Donzi causes me enough trouble - making good use of my vast experience in small craft design, I wisely installed a very conservative 486 dyno-proven HP in the little 'skiff'.

Can you email me any and all pictures of the little "skiff" to highlnd@telus.net :D

As the owner of a few, and a passion for them all (early DONZI's) I would love to see what you have created.

Thanx, Lenny :)

BMcF

03-16-2007, 09:53 AM

Can you email me any and all pictures of the little "skiff" to highlnd@telus.net :D

As the owner of a few, and a passion for them all (early DONZI's) I would love to see what you have created.

Thanx, Lenny :)

done.

brian eiland

03-16-2007, 08:12 PM

...I saw this little letter in Feb issue of Popular Science and had a laugh, but it certainly rings true

I have to laugh every time I see a 'stealth' ship reported as an innovation in design ["Invisible Warship", Concepts & Prototypes, Nov]

Having served on a submarine, I can tell you that any surface ship is a target. It is hard to hide an elephant on a football field, even a ninja Navy elephant.

Submarines are by nature far less visible. Perhaps we should invest in new submarine designs rather than white elephants.
Ken Russell

FAST FRED

03-17-2007, 05:28 AM

"Submarines are by nature far less visible."

NOT to us ASW folks , subs make NOISE , not much , but usually enough to track & kill.

Torpedos go WAY! faster than subs, even nukes.

FF

brian eiland

03-17-2007, 08:57 AM

I spent a few years working with the subs back in the early 70's with the intro of Mk48, Subroc, etc. And ASW as well.

I'd place my bets on the sub, given the choice

FAST FRED

03-18-2007, 05:05 AM

I'd place my bets on the sub, given the choice

Even knowing many torpedos have Nuke warheads?

Overpressure kills subs at depth , nukes are good at overpressure.

I would expect tho the next attack on the USA will be with purchased bio weapons from the many excellent well funded Cuban labs.

FF

Kobus Potgieter

03-18-2007, 08:46 AM

I have also been working on a stealth project and have been doing a lot of research in stealth technology. I agree with the comments - this design is not stealth at all. Stealth is the angle of surface placed in such a way that it reflects the radar signal. This is stealth. Your design will work quite well as an offshore racer.

kach22i

03-19-2007, 01:29 PM

Stealth is the angle of surface placed in such a way that it reflects the radar signal.
It seems then that you have at least five choices.

1. Surface piercing hull so that the hull is angled skyward and not downward to be reflected by the water.

2. Make the craft out of something radar transparent in lieu of radar reflective.

3. Coat the craft with a magic-like radar absorbing material.

4. Put it under the water as suggested earlier.

5. Make it go over the water like a SES or hovercraft, and treat the surfaces under the skirt with great care. The skirt maybe out of a material to abosorb radar waves - or not.

Kobus Potgieter

03-19-2007, 03:20 PM

It seems then that you have at least five choices.

1. Surface piercing hull so that the hull is angled skyward and not downward to be reflected by the water.

2. Make the craft out of something radar transparent in lieu of radar reflective.

3. Coat the craft with a magic-like radar absorbing material.

4. Put it under the water as suggested earlier.

5. Make it go over the water like a SES or hovercraft, and treat the surfaces under the skirt with great care. The skirt maybe out of a material to abosorb radar waves - or not.

point1 . remember that the topside play a major role with rader deflection.
point3. radar absorbing materials are available. a good sandwish construction also help to a point. This is however very expensive
point 4. what can i say
point 5 . whatever is above the WL, radr will pick up and again surface angles are important.

kach22i

03-19-2007, 04:04 PM

point1 . remember that the topside play a major role with rader deflection.

For air to surface "looking down" radar I would agree.

However surface to surface radar would pick up the lower hull to water surface interaction, right?

Or would the radar waves be bounced high upward away from the source?

Sample:
http://www.physorg.com/news64672001.html
http://www.physorg.com/newman/gfx/news/us_navy3.gif
Note how much attention has been paid to making the ship less visible to radar – all exterior surfaces are smoothed and angled to present the smallest possible profile – almost looks like a surfaced sub, its primary enemy.

brian eiland

04-24-2007, 01:33 AM

....And finally I was going to ask if you had ever contributed your views of this design to that subject thread at Yachtforums,
Trimarans and the Bladerunner
http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner-7.html (http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner-7.html)
..but I just looked there and found you did recently make a posting. I think you should repeat that posting you made here and see what reaction you get on the other site??...should be interesting

Great learning on these forums...information sharing!!
For those who do not frequent this other forum there have been a few interesting additions recently.

kach22i

04-25-2007, 06:46 AM

For those who do not frequent this other forum there have been a few interesting additions recently.

That Triton on page 8 (with links) is an odd duck, but I like it.:)

dan lys

12-07-2007, 10:51 PM

hey alex its dan lys your old clay modeling buddy from ccs, email me at dlys83@hotmail.com, i just heard ur out in minnesota or some **** like that, hit me up asap cause i might be headin down to miami and i figured id catch u for a drink, hit me up guy......oh ya and i heard rob cameron got married lol u kno his wife controls his ass lol, oh and miljan just got into toyota, theyre working his ass off he told me......nice boat by the way lol....k guy hit me up cya

rambat

12-09-2007, 02:00 AM

Safe Walrus has said it best I think "Remember as has been said above stealth ain't just about low radar signature! People got ears and can use 'em so you need QUIET engines "

Effective clandestine jobs done from small boats have to mostly go under "human radar", seldom is there active radar in regions were we are "not" officially involved. A real stealth insertion craft should have sophisticated mufflers, low profile design to get lost in even slight waves, over the horizon range and speed to limit the time at risk of exposure. A real different scenario from stealth requirements of bigger surface ships.

Biggest issue to encourage all of us to start discussing (smaller?) hull alternatives is not speed or radar stealth but to improve human factors. We have simple platued with our ability to take a seal team at high speed on a Vee hull and have them ready for anything other than triage. Any offshore racer will confirm the bloody urine and the compressed spines, yet racing is a hobby, not regular deployment, its a real problem. We could devise a suspension couch or complete cab separate from the surface hull, like this butchered Mark V. render. Won't help the mechanicals much....

I'll show my bias here again and suggest an Air-Cushion hull is the best next evolution. This thread showcased the Blade runner, I love its look and it was a bold brave venture. I will try to be as bold and suggest a "phase two" be explored by the application of a full bow wrapping bag/finger seal. I showcased this similar "Hybrid" SES hull form a few months back, it could be argued this set-up would soften the ride, maintain a flatter roll, eliminate that scary bow pitch potential. The over all HP could be shared to drive some fans for about the same speed, since the overall drag goes down. Those side sponsons could be modified as planning amas for roll stability and digging resistance. BMcF could add something here I am sure

kach22i

12-09-2007, 02:01 PM

FYI: An old post of mine from the Hovercraft Club of America forum...............

UPDATE: 10/18/2007
http://www.hoverclubofamerica.org/forum/index.php?showtopic=1244&st=75&p=13190&#entry13190
This is the first information I've seen on underwater sounds made by hovercraft.

The Journal of the Acoustical Society of America
http://scitation.aip.org/getabs/servlet/Ge...ps&gifs=yes (http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JASMAN000118000006003646000001&idtype=cvips&gifs=yes)
Underwater and in-air sounds from a small hovercraft

Susanna B. Blackwell and Charles R. Greene, Jr.
Greeneridge Sciences Inc., 1411 Firestone Road, Goleta, California 93117

(Received 3 August 2004; revised 9 September 2005; accepted 19 September 2005)

Underwater and in-air recordings were made from a boat anchored near Prudhoe Bay, Alaska, while a Griffon 2000TD hovercraft drove by at or near full power on four passes. At the closest point of approach (CPA, 6.5 m), underwater broadband (10–10 000 Hz) levels reached 133 and 131 dB re: 1 µPa at depths of 1 and 7 m, respectively. In-air unweighted and A-weighted broadband (10–10 000 Hz) levels reached 104 and 97 dB re: 20 µPa, respectively. The hovercraft produced sound at a wide range of frequencies. Both underwater and in air, the largest spectral peak was near 87 Hz, which corresponded to the blade rate of the thrust propeller. In addition, the spectral composition included several harmonics of this frequency. The shaft or blade rate of the lift fan was barely detectable underwater despite its proximity to the water. The hovercraft was considerably quieter underwater than similar-sized conventional vessels and may be an attractive alternative when there is concern over underwater sounds. ©2005 Acoustical Society of America

EDIT:
A thread on acoustics and sound..........
http://www.hoverclubofamerica.org/forum/index.php?showtopic=903&hl=acoustics

kach22i

12-09-2007, 02:12 PM

I'll show my bias here again and suggest an Air-Cushion hull is the best next evolution.

What was your old user name?

DCCD, David - right?

rambat

12-09-2007, 05:43 PM

Yes, dccd or Rambat I must be registered twice as I have long lurked and seldom commented.

We as designers need to think about mission phase, long range transits have different priiorityies than up close insertion. So if you have an ACV/WheledAmphibian, it could be hull born for economy transform into ACV mode to get over shore. Just the opposite if the transit needs to keep the men fresh and you can go feet dry with wheels etc..

Rotorcraft can do it all except keep quiet, carry any real load long range or do it cheaply while losing itself in the surface clutter Again I think a Mark V sized ACV using the old Bell 1967 SKRM-1 as a starting point could be the answer and am working up just a design. The US Navy SKMR-1 was a 6' gound clearence flying 25 ton Air cushion craft, built in 1967. Its particulars were 45000 lb, plus 2000 lbs payload, 8000 lbs fuel, 4320 hp total, 70 knots. Noise wieght and controlability killed it as it has sidelined hovercraft design ever since. I will apply in my new design 2007 composites to save 60% strucure wieght, offer 2x2000 hp gasoline "silenced" engines (short missions) elec stability and eliminate the axle fans and thier mission killer noise. Stay tuned. And feel free to offer any constructive comments.

GTO

12-09-2007, 09:02 PM

I think an objects radar signature is much more complex than just plate angles and putting a coat of RAM over a structure.

Having worked "around" some radar analysts and technicians, there are a couple of points worth mentioning that make the entire "stealth" vehicle a difficult beast to design.

1. Most everything has a radar signature.
2. Radar reflections interact. For example, 2 point sources may either amplify each other (peak-peak), or cancel each other out (peak-valley). Also, this means that the resulting radar reflection path may not be what one would expect from the angle of the reflective part. As the reflected radar waves interact from various sources on the vehicle, you could end up with a beam pointing right at the transmitter. Essentially, a passive phased array (or electronically tuned) beam.

So what does this mean in real life?

If coatings and plate angles for a design are not fully analyzed/tested, as a whole, it is possible that the resulting radar signature could be even worse than a standard "non-stealth" design.

Take a RAM coating for instance. Slap on layer of RAM paint. Okay, test results indicate a reduced signature. Well more is better, right? Paint on another layer. Now, the signature is much worse. What happened? The two layers of RAM had returns that amplified, negating the RAM.

Anyway, if this is basic info everyone here is aware of, sorry to waste the space.

kach22i

12-10-2007, 10:47 AM

I will apply in my new design 2007 composites to save 60% strucure wieght, offer 2x2000 hp gasoline "silenced" engines (short missions) elec stability and eliminate the axle fans and thier mission killer noise. Stay tuned. And feel free to offer any constructive comments.

1. Does the new design have a client or is it speculative?

2. Gasoline? Doesn't the military want to use the same Diesel fuel in everything?

3. Axial fans help prevent "heave acceleration" in rough weather as I understand it. Can't active noise cancellation (speakers) be applied somehow, or perhaps many right angled turns with absorbtion?

4. I have a design on grid/sketch paper which is a little smaller than a Mark-V and hope to build a scale working model of it. The model will take time and money which is short supply right now. Any ideas on how to find a patron or sponsor?

kach22i

12-10-2007, 10:50 AM

Anyway, if this is basic info everyone here is aware of, sorry to waste the space.
Good information, thanks GTO.

Isn't there a cheap way with a mass model, a high powered flash light or low powered laser in a dark room to get a general idea on what will bounce back?

Ramius41

12-10-2007, 11:21 AM

1. Does the new design have a client or is it speculative?

2. Gasoline? Doesn't the military want to use the same Diesel fuel in everything?

3. Axial fans help prevent "heave acceleration" in rough weather as I understand it. Can't active noise cancellation (speakers) be applied somehow, or perhaps many right angled turns with absorbtion?

4. I have a design on grid/sketch paper which is a little smaller than a Mark-V and hope to build a scale working model of it. The model will take time and money which is short supply right now. Any ideas on how to find a patron or sponsor?

1....Probably

2....Name a 2000hp diesel that doesnt weigh as much as a house....and most of the military's uav's arent diesel.

3....Lets try not to overload the craft with weight before they get the actual payload in it!

4....BEG!!!...:D

kach22i

12-10-2007, 11:58 AM

The B.E.G. method....................not that again.;)

I wonder how old this picture is.

San Diego boat movers..............
Navy air cushion
http://www.sandiegoboatmovers.com/moves_military.htm
http://www.sandiegoboatmovers.com/images/move_gallery/military/sliced_images/NavyAirCushion_edited_1x1.jpghttp://www.sandiegoboatmovers.com/images/move_gallery/military/sliced_images/NavyAirCushion_edited_1x2.jpghttp://www.sandiegoboatmovers.com/images/move_gallery/military/sliced_images/NavyAirCushion_edited_1x3.jpg

rambat

12-10-2007, 01:56 PM

GTO

12-10-2007, 02:09 PM

Isn't there a cheap way with a mass model, a high powered flash light or low powered laser in a dark room to get a general idea on what will bounce back?

Not really. If you consider a wire, shining a light on it will create a shadow on the opposite side. Hit the same wire with RF energy of the right frequency, and it becomes an omidirectional reflector. Unless you create your model with optical characteristics that mimic the RF energy characterics (which you don't really know, which is why you built the model in the first place) then that wouldn't work. And your model is no longer cheap.

Thats why RF absorbing chambers are popular for design work.

kach22i

12-10-2007, 07:04 PM

Not really. If you consider a wire,
What if considering an all composite design hovercraft or SES?

I don't think a plastic/composite/fiberglass wire would carry a signal like a metal one, would it?

I guess one would have to avoid using metal ties to secure the rubber skirt with.

martin k

12-10-2007, 07:26 PM

Alex, I reckon your boat has zero stealth.
Gas turbines run very hot so your exhaust plume will give you away for a start. And I don't think the boat is big enough to incorporate sufficient exhaust cooling arrangements.
Also, the beautiful domed cowl is perfect for reflecting radar, no matter what the attitude of the vessel is.
If you design a true stealth vessel, then speed becomes a secondary consideration, depending on operations in mind. 60 knots or 30 knots becomes the difference between transporting a team of 5 or 25.
You need to settle on functional targets, then design accordingly.

GTO

12-10-2007, 11:22 PM

What if considering an all composite design hovercraft or SES?
I don't think a plastic/composite/fiberglass wire would carry a signal like a metal one, would it?

I can't directly answer your question as it all depends on the materials used in the composite construction. If the materials used had a radar signature for the frequencies of interest, a study would have to be made of the signal interaction between each laminate. Again, the structure has to be analyzed as a whole. Although I would think fiberglass does have a much smaller signature than a metal, you would still have to confirm that as a whole, the signature reduction is good enough.

Mil-spec radars are GOOD and depending on the ROEs in place, a weapons commander might look at an intermittent return and say, "Hell, I'm bored, put a missile on it and see what happens."

BMcF

12-13-2007, 01:26 PM

Its a 90' 1989 SES hull, surface propelled. Rohr built it. If I can can find my file I'll upload the layout, a very advanced SES for its time, And I think it was used heavily for various task in the US Navy.

ahh, yes..the 'hulk' as she became known in Navy circles. 'Sea Viking' SES SpecWar SES..aborted in mid 80's when completed only to point seen in that pic. Waterjet propulsion, centrifugal lift fans, and a digital vent valve based heave attentuation system (HAS or RCS), built by us.

Only thing that pile-o-aluminum ever did was some limited duty as a radar target for signature testing to see if they had at least been on the 'right track' with the low-signature design..and that was about all she ever did before hitting the scrap pile. Considered an 'advanced SES' by the folks in teh program office (nuff said) she was actually already sunk by the weight of too many combined requirements, well before the construction began...so her ignominious end was actually a blessing disguise..she would have been a total pig in the perfromance area.

Fortunately, we received permission from DoD to re-sell the HAS package (protected/retricted military technology at the time) to a Norwegian company for a prototype high-speed ferry SES and it was launched in Hyen, Norway (and still in service.in Malta now, I belive) in ..86?..as the 'Fjordkongen'. 'Fjordkongen' was about the only thing that ever made any use of the residue of the 'Sea Viking' that I was aware of.

BTW..noting an earlier comment in this same thread.axial lift fans were 'abandoned' for lift fan use in the late 70's..too complex and too susceptible to unrecoverable total stall, where centrifugal fans are not. And..axials made heave resonance and acoustic resonances worse than a centrifugal too...

kach22i

12-13-2007, 02:05 PM

BTW..noting an earlier comment in this same thread.axial lift fans were 'abandoned' for lift fan use in the late 70's..too complex and too susceptible to unrecoverable total stall, where centrifugal fans are not. And..axials made heave resonance and acoustic resonances worse than a centrifugal too...

I've read that the axial fans on some early British hovercraft exploded from the heave pressure load of wave impact and cushion variation which heavy seas presented. These axial fans were replaced with centrifugal fans without further incident.

Request For Information (RFI):
Does anyone know of a hovercraft or hovercraft model using a "Mixed Flow" fan? From my reading it might be the best compromise between an Axial Fan and a Centrifugal Fan. Would kind of look like something off a hair blow dryer or floor cleaning vacuum fan. The first version or prototype of the Jeff (A) may of had these, replaced by somekind of right angle axial impeller, replaced by split thrust (one for lift, one for roof mounted directional thruster) centrifugal lift fan.

Axial Fan Note:
In the book...........
Theory and Design of Air Cushion Craft (ISBN: 0340676507)
Yun, Liang Bliault, Alan
http://www.abebooks.com/servlet/SearchResu...76507&nsa=1 (http://www.abebooks.com/servlet/SearchResults?&isbn=0340676507&nsa=1)

There are several large Russian hovercraft which use axial fans for lift. The Brit's and Chinese favor centrifugal lift fans. There is a chart in the book listed above. PM me and I might get around to sending you (any of you) that page.

I don't want to post copyrighted materials which I've scanned myself.

BMcF

12-13-2007, 02:14 PM

The Jeff-A used mixed flow lift fans, IIRC. They were purched later by Gentry, intended for use in his aborted trans-Atlantic record attempting SES design that Chris McKesson and John Connor were developing. They had some serious blade cracking problems when initially produced for the Jeff test craft..again if the old memory serves me right. Chris will probably see this thread and set me straight on that one if I erred.:D

The use of axial fans in hovercraft is more prevalent and less problematic...because the leakage is inherently much higher than that of an SES and always a lot of leakage present at all times when on cushion (why the 'less leaky' but non-amphibious 'sidewall hovercraft', later 'SES', was invented in the first place after all) and thus provides a 'relief valve' that makes stall less likely.

The old SES-100 A could be lift-stalled and that then required that she be set back down on her bottom again so that the fans could recover from the stall..as an example of why axials were evantually abandoned. In the short term..several operational restrictions and additional stall prevention venting mechanism were added to the 100A so that she could complete her trials programs through about 1980 or so.

kach22i

12-13-2007, 02:16 PM

Considered an 'advanced SES' by the folks in teh program office (nuff said) she was actually already sunk by the weight of too many combined requirements

Did the weight of the engines have anything to do with it being overweight?

http://ntlsearch.bts.gov/tris/record/tris/00691346.html
Principal particulars are: Length oa 82ft 6in; Breadth 35ft; Draught on/off cushion 5ft 4in/8ft 4in; Max. full load displace,ment 116t. Propulsion is by a pair of 1800 bhp diesel engines driving twin cp propellers.

BMcF

12-13-2007, 02:23 PM

Did the weight of the engines have anything to do with it being overweight?

http://ntlsearch.bts.gov/tris/record/tris/00691346.html

Not really...all 'like' vessels produced afterwards use, or used, similar diesels. And I goofed..it was a successor design to SWCM that used jet propulsion..although I thought jets were substitued for the CP solution late in the Sea Viking design phase..

The problem with Sea viking is the same as has plagued nearly every Navy attempt to build a high-speed surface craft (witness the PCs..witness very soon the first LCS..nuff said again)) where too much 'stuff' gets piled on a very weight-senstive hull technology..whereupon its no longer 'fast' at the end of the day, most often resulting in total abandonment during the design phase.

kach22i

12-14-2007, 10:06 AM

Just to clear up a long standing confusion on my part;

1. The "Jeff-B" (EDITED; I meant to say Jeff-B not "A", had to look it up- oops LCAC prototype) lift fans which are tied into the bow/stern thrusters were originally "Mixed-Flow Impellers" - right?

2. Were they axial or radial?

3. Were they single or dual on a common axle?

4. These were the ones which you could see straight though when spinning at speed, right?

5. The mixed-flow fan(s) were drawing in air from the port and starboard as well as the cargo well area, right?

6. The mixed flow fans worked fine but were switched to higher pressure centrifugal fans when the military once again stuffed 10 lbs of organic fertilizer into a 5 lb bag, right?

7. I mean to say that the Navy raised the system requirements (added weight) and even larger mixed-flow fans would not fit, or that centrifugal fans had some kind of other advantage yet not discussed.

kach22i

12-14-2007, 10:22 AM

The reason I was thinking axial fans are better than centrifugal fans for amphibious hovercraft (when considering heave acceleration) is that someone once told me axial fans have a flatter HQ curve.

Some info here (non-hovercraft):
http://ateam.lbl.gov/Design-Guide/DGHtm/fans.htm

Example (non-hovercaft):
http://ateam.lbl.gov/Design-Guide/DGHtm/centrifugalvs.vane.axialfans.htm
http://ateam.lbl.gov/Design-Guide/DGHtm/bitmaps/help0034.jpg
Centrifugal vs. vane-axial fans
The choice of forward-curved centrifugal or backward-inclined centrifugal or airfoil centrifugal fans versus vane-axial fans will affect the energy efficiency. Standard centrifugal fan systems are typically very inefficient (50 percent to 60 percent), and their actual installed efficiency is usually much worse than the manufacturer's ratings. Efficiencies as low as 30 to 40 percent have been measured in the field. It is recommended that high-efficiency (80 percent to 90 percent) axial airfoil fans be considered with direct drive and static regain devices. However, flexibility of adjustments will be compromised. [Naughton, "HVAC Systems… Part 1," 1990; Micro-Electronics Facility Efficiency Workshop, 1995]

Sometimes the less you know, the more open to learning you are. I'm an open book, tell me what you know.;)

BMcF

12-14-2007, 10:37 AM

Just to clear up a long standing confusion on my part;

1. The "Jeff-A" (LCAC prototype) lift fans which are tied into the bow/stern thrusters were originally "Mixed-Flow Impellers" - right?

The two Jeff craft, A (Bell)and B(Aerojet General) were competing propotypes for the LCAC. The 'B boat' won. The B had air thrusters over centrifugal (HEBA) fans. The B had two airscrews in the stern. The 'A' had mixed-flow lift fans and four air-screw propulsors, each 'module steerable through 360 of rotation.

2. Were they axial or radial? See above

3. Were they single or dual on a common axle? Not as familiar with A boat..the B has two DWDI fans on common shaft line, two port and two starboard.

4. These were the ones which you could see straight though when spinning at speed, right? No..beign DWDI, you cannot see through them due to center disk unless yr Superman.:D

5. The mixed-flow fan(s) were drawing in air from the port and starboard as well as the cargo well area, right? Again..I'm not as familiar with A-boat details....although I have them aroudn the archives here somewhere

6. The mixed flow fans worked fine but were switched to higher pressure centrifugal fans when the military once again stuffed 10 lbs of organic fertilizer into a 5 lb bag, right? Other way around..

7. I mean to say that the Navy raised the system requirements (added weight) and even larger mixed-flow fans would not fit, or that centrifugal fans had some kind of other advantage yet not discussed.

Mixed-flow and RD (radial diffuser) lift fans were proposed for several concepts (3KSES for example) that got a bit..er..obese as they approached final design completion stage. We now know from building many SES' since then that it was a pointless exercise for the most part. What I mean by that is that if you need fans that have higher pressure ratio than the HEBA centrifugal can deliver, yr already exceeding rational cushion loading ..and zee design will be a peeeg.;)

kach22i

12-14-2007, 11:25 AM

Mixed-flow and RD (radial diffuser) lift fans were proposed for several concepts (3KSES for example)

I'm assuming that Mixed-Flow fans would of been considered as a compromised in between axial and centrifugal fans (best of both) and not as something to provide even more pressure than a centrifugal fan.

What am I missing here?

BMcF

12-14-2007, 04:01 PM

I'm assuming that Mixed-Flow fans would of been considered as a compromised in between axial and centrifugal fans (best of both) and not as something to provide even more pressure than a centrifugal fan.

What am I missing here?

Mixed flow designs (witness turbochargers) are used to create higher delta-P across the 'machine' than can typically be achieved by purely radial centrifugal fans. That is a gross simplification that ignores so many other design factors...but one factor that seriously mitigates against using mixed flow whels is their complexity of construction. Airfoil centrifugal wheels are SO much easier to build.

kach22i

12-18-2007, 11:27 AM

Mixed flow designs (witness turbochargers) are used to create higher delta-P across the 'machine' than can typically be achieved by purely radial centrifugal fans. That is a gross simplification that ignores so many other design factors...but one factor that seriously mitigates against using mixed flow whels is their complexity of construction. Airfoil centrifugal wheels are SO much easier to build.

The rubbery plastic injected ones (vacuums and blow dryer type) are limited to what size and power?

I'm building a scale hovercraft model, looking to use about a three inch diameter.

Has CNC machining rewritten the rule book on what can be made and scaled up?

BMcF

12-18-2007, 11:39 AM

The rubbery plastic injected ones (vacuums and blow dryer type) are limited to what size and power?

I'm building a scale hovercraft model, looking to use about a three inch diameter.

Has CNC machining rewritten the rule book on what can be made and scaled up?

You would know more about the scale fans than I probably. We use either axial muffin fans or FC (furnace blower or squirrel cage) types in the models we build...or a combination fo the two. The 57' radio-controlled 1/20 scale model SES that we are currently building has two 1.5 HP FC squirrel-cage blowers for lift air and 3 Rotron axial muffin fans to act as 'boost fans' for stern seal inflation.

I'm partial to the FC fans for full-scale application as stern seal inflation boost fans. Great pressure rise and flow in a compact min-diameter package..not so great in efficiency but that gets lost in the 'noise' when you consider they average only about 15-20 HP each.

As far as I know..all the mixed flow wheels are/were cast...

kach22i

12-18-2007, 02:57 PM

The Jeff-A used mixed flow lift fans, IIRC. They were purched later by Gentry, intended for use in his aborted trans-Atlantic record attempting SES design

I could find nothing on the second SES, but found this on the Gentry Eagle boat.

FOR SALE:
"Own a Piece of History. This is a rare opportunity to be the only person in the world privileged to experience the speed, adventure and prestige of owning Gentry Eagle."
http://www.gentryeagle.com/
Transatlantic crossing record
Ambrose Lighthouse at the entrance to New York Harbor to
Bishop Rock on England's Isles of Scilly.
Boat: Gentry Eagle
Record time: 62 hours & 7 minutes

The SES you are working on is over one thousand feet long?

57 x 20 = 1,140 feet long................or is the model about three feet long?

57 x 12 divided by 20 = 34.2" long?

What good is 1/20th scale?

I thought it had to be at least 1/6 scale to be of any use.

BMcF

12-18-2007, 03:43 PM

I could find nothing on the second SES, but found this on the Gentry Eagle boat.

FOR SALE:
"Own a Piece of History. This is a rare opportunity to be the only person in the world privileged to experience the speed, adventure and prestige of owning Gentry Eagle."
http://www.gentryeagle.com/

The SES you are working on is over one thousand feet long?

57 x 20 = 1,140 feet long................or is the model about three feet long?

57 x 12 divided by 20 = 34.2" long?

What good is 1/20th scale?

I thought it had to be at least 1/6 scale to be of any use.

1140 feet LOA..you got it! 1:20 is fine..1:6 is better..1:1 is best.:D

Gentry and his team never got to finish the SES..the project collapsed when he went in to teh coma and never recovered.

kach22i

12-18-2007, 05:31 PM

1140 feet LOA..you got it! 1:20 is fine..1:6 is better..1:1 is best.:D

The 57' radio-controlled 1/20 scale model SES that we are currently building has two 1.5 HP FC squirrel-cage blowers for lift air and 3 Rotron axial muffin fans to act as 'boost fans' for stern seal inflation.

Maybe my math is wrong; let's say a total lift of 10 HP assuming a useable 7.5 HP of lift, right? (1.5 x 5 = 7.5)

I think 20 foot long hovercraft (not an SES) uses at least 20 HP for lift.

Example:
http://www.hovercraft.com/content/index.php?main_page=index&cPath=35_55

Therefore, a 60 foot long hovercraft might be using 60 HP (I'll check an old Jane's Surface Skimmer's - 1976 or 1987, later).

The SES uses 1/6 the lift which a fully amphibious hovercraft uses?

I could believe 1/2 the power requirement, but 1/6?

Is this more of a air assisted cat?

kach22i

12-19-2007, 01:14 PM

Found this..........................no good pictures though.

http://www.globalsecurity.org/military/systems/ship/hss.htm
Surface Effect Vessel (SEV)

Surface Effect Vessel (SEV) are hybrid surface effect ships that incorporate rigid catamaran-like sidehulls and bow and stern seals to create a plenum pressurized by air. The result is a craft which is 80 percent supported by pressurized air and 20 percent supported by buoyancy. When the plenum is pressurized (on-cushion), the wetted surface of the sidehulls is reduced, reducing drag and allowing high speeds.

Litton Ingalls Shipbuilding has designed (concept design) a transoceanic SEV capable of average transit speeds of 70-75 knots with payloads of 5,000 short tons over a range of 8,700 nautical miles. Ingalls is also designing a smaller coastal SEV (container/RO/RO) as a possible contender for the Army Theater Logistic Vessel (TLV) requirement, and a fast ferry SEV (RO/PAX) that may have intra-theater or riverine warfare applications. The transoceanic and coastal SEV designs are gas turbine powered, water jet propelled and have shallow drafts. They can transport both track and wheeled vehicles as well as containers and will be self-sustaining (i.e., can offload itself) vessels that can rapidly offload in damaged or austere ports, or directly across a beach without the aid of JLOTS. The speed and payload of the vessel would provide the JFC with the capability to strategically maneuver forces into positions of operational advantage on a global basis. The vessel's shallow draft, coupled with its other features would make it useful for maneuvering forces within the theater. It could provide the JFC with the element of surprise and keep the adversary "off balance" because his entire shoreline would be vulnerable to attack.

The need for high speed, heavy payload capable, long distance transportation has led to the investigation of alternate ship designs capable of performing highspeed sealift. Several options are being explored including hydrofoils, multi-hulls, air cushion vehicles, and semi-planing hulls. A proposed commercial example of the latter variety is thought to be capable of 40+ knots with a payload of over 8,000 long tons. Appraisals of the technical feasibility of developing a 50-kt displacement-hull type ship capable of delivering a 12,000 LT payload over a distance of 9000 nm concluded that this ship will have a length of 1500 ft, a displacement of 64,000 LT, a draft of 30 ft, a length/beam ratio of 12.6 and a transport efficiency factor nearly twice that of any existing 50-kt ship. Further, it will require nearly 600,000 hp, which is substantially larger than that in any existing marine vessel.

BMcF

12-19-2007, 02:50 PM

The 57' radio-controlled 1/20 scale model SES that we are currently building has two 1.5 HP FC squirrel-cage blowers for lift air and 3 Rotron axial muffin fans to act as 'boost fans' for stern seal inflation.

Maybe my math is wrong; let's say a total lift of 10 HP assuming a useable 7.5 HP of lift, right? (1.5 x 5 = 7.5)

I think 20 foot long hovercraft (not an SES) uses at least 20 HP for lift.

Example:
http://www.hovercraft.com/content/index.php?main_page=index&cPath=35_55

Therefore, a 60 foot long hovercraft might be using 60 HP (I'll check an old Jane's Surface Skimmer's - 1976 or 1987, later).

The SES uses 1/6 the lift which a fully amphibious hovercraft uses?

I could believe 1/2 the power requirement, but 1/6?

Is this more of a air assisted cat?

Yes..the air leakage is much lower for an SES than for an ACV. An since the leakage is mostly from the bow and stern, it is not greatly affected by increasing the cushioni Length to beam ratio by lengthening the cushion..thus this 10:1 L/B high-speed sealift 'thing' we are building has very low flow requirements for its size. We just completed a program review on the model build phase and I'll get some pictures posted up here soon. At 57' LOA, it is one of the larger remote-controlled scale models ever built.

kach22i

12-19-2007, 03:19 PM

At 57' LOA, it is one of the larger remote-controlled scale models ever built.

Largest I know of, including boats and aircraft.

Your competition....................?

SES pictures...................models too.
Blyth Bridges Marine Consultants Limited
http://www.blythbridges.co.uk/projects_column.html
http://www.blythbridges.co.uk/Pictures/sec_model.jpg
http://www.blythbridges.co.uk/Pictures/SEC.JPG
http://www.blythbridges.co.uk/Pictures/CNV.JPG

BMcF

12-19-2007, 04:15 PM

ah yes..my old friends Andy Blyth and David Bridges. Been quite some years since we worked together on some of those SES concepts.

Our competition for..what?

kach22i

12-20-2007, 03:27 PM

Our competition for..what?

Model testing?

Solving ride, stability and buoyancy issues for surface craft of unconventional design?

I thought there was some overlap of services, my mistake?

FYI:
Right now I'm building a five foot long hovercraft model. It started out as a mock-up study for the cabin area only, and just to see if it would work as intended. I enjoy taking plan and section sketches beyond the 2D and into model form, real models (3D) not computer models.

I kind of got carried away and now there is no turning back.:D

I just picked up three (3") mixed flow fans from a vacuum cleaner repair shop ($15). I also picked up two (4") axial fans for thrust ($10) from an appliance repair shop.

I have the electric motors and NICAD batteries from a few years ago and now have to make it all come together somehow.:(

BMcF

12-20-2007, 08:54 PM

Model testing?

Solving ride, stability and buoyancy issues for surface craft of unconventional design?

I thought there was some overlap of services, my mistake?

FYI:
Right now I'm building a five foot long hovercraft model. It started out as a mock-up study for the cabin area only, and just to see if it would work as intended. I enjoy taking plan and section sketches beyond the 2D and into model form, real models (3D) not computer models.

I kind of got carried away and now there is no turning back.:D

I just picked up three (3") mixed flow fans from a vacuum cleaner repair shop ($15). I also picked up two (4") axial fans for thrust ($10) from an appliance repair shop.

I have the electric motors and NICAD batteries from a few years ago and now have to make it all come together somehow.:(

Sounds like a sweet model..and big. I like big..:D

No mistake on your part..I just didn't know who or what you were referring to as far as competition. We have competitors..but few and we compete in a very small market. Collaboration is as often the case as direct competition..

Our biggest source of work is supporting the 'big boys'..US and foreign navies and larger design houses and shipyards that don't have the expertise in-house to design and build the 'weird ones'..SES, ACV, SWATH, hydrofoils, cats, and hybrids thereof. Stabilization, or 'ride control' used to be our main specialty and primary business, but that morphed in to 'whole ship' design over the last 20+ years and now the ride control systems are a secondary part of our business today..even though we are one of only a handfull of companies worldwide that produce such systems.

kach22i

12-21-2007, 11:12 AM

Sounds like a sweet model..and big. I like big..:D

I made three cut-out men out of foam about six inches tall. Somehow the scale change (making it larger) caught me by suprise.

I have to follow the drawings more closely now, this takes a little of the fun (sculptural and design aspect) out of it. One of the main reasons I like to build models so much is that it forces me to make things simpler than I tend to draw them. I leveled out some of my floor area level changes for instance (less tripping).

The main problem I discovered is that I deviated from the drawings for the roof openings. Roof mounted 50 cal gun turrets were first cut to only a 24" diameter (shoulder width). My previous drawings show 36" opening for single 50 cal and 48" dia. for a double 50 cal. These dimensions are based on the old Vietnam era PBR (bow gunner) patrol boat and SK5 hovercraft (roof gunners).

If anyone knows if modern gun fittings and openings are different (such as found on the roof of a Humvee) please let me know. This information is hard to come by and I've been scaling plastic models and photographs which I have collected over the years.

kach22i

03-11-2008, 04:13 PM

Somewhere in this thread this design was mentioned, so I'm posting this here for future reference.

http://www.connormarine.com/pages/9/page9.html?refresh=1111977204133
http://www.connormarine.com/images/600_gt185rendering.JPG
http://www.connormarine.com/images/600_Untitled-1.psd.jpg
185' SES Catamaran, 100+knots, turbine powered, Designed by Connor Marine for new Transatlantic Speed Record

WALKERS210

05-27-2008, 12:07 AM

Boys....go look up SES 100A and SES 100B. Both SES's, different concepts, different designs, different support factors.

Today in high speed vessels there are not distinct types, but rather hybrids. Think of a design area shaped like a triangle with hydrofoils at the apex (solely supported by hydrodynamic forces), cats and monohulls at one bottom point (solely supported by hydrostatics), and ACVs and airplanes at the other (solely supported by areodynamics). Most power cats are along line between cats and hydrofoils, ekanroplanes along the line between hydofoils and ACVs. SESs are along the baseline, each design falling somewere between cats and ACVs depending on the distribution of lift at any given time.

I know this is an older post, I found it doing a google search for info on the SES 100's. In 1972 I was assigned to the Navy's newest test facilty SESTF (Surface Effect Ship Test Facility) based at Naval Air Station Patuxent River, Md. I have read some of the post but the one following the one I quoted from questioned if the bow seal was damaged that the SES would pretty much crash and burn. I brought up the exact questions to engineers from Bell Aerospace and the Navy pilot. I was told that it would take major failure like loosing the entire bow seal to cause it to nosedive. However the very first SES built was about 25 ft in length and had plywood bow and stern seals that were hinged to hull. It was powered by a Mercury 150hp outboard, with 2 Briggs and Stratton (mower) engines that provided the air flow for lift. It ran on the Potomic river and in fact had a failure of the bow seal which resulted in both crew members being killed. I know its been darn near 35 years and the program has long since been scrapped. But it was a sight to see when the SES 100B went over the HUMP (18kts speed it would outrun its own depression in water) then it was gone. 1975 SES100B running in St Andrews bay in Panama City, Fl reached a speed of around 110kts. The Sidewalls were designed to hold in the air for lift and provide a way to stop or reduce the side slip while executing a turn. Somewhere in my old pile of junk I think I still have pictures of the SES 100B and even the SES100A.

kach22i

05-27-2008, 08:33 AM

SES built was about 25 ft in length.......... It ran on the Potomic river and in fact had a failure of the bow seal which resulted in both crew members being killed.
I did not know this story, how tragic.

I may have pictures of that test craft in my Jane's Surface Skimmers 1975-76, it's description sure does sound familiar.

brian eiland

09-04-2009, 10:44 PM

I assume you are familar with Dick Newick's tri-hull powerboat
http://www.yachtforums.com/forums/16142-post55.html (http://www.yachtforums.com/forums/16142-post55.html)

...or Peter Payne's work down there on Chesapeake Bay, Sea Knife
http://www.yachtforums.com/forums/16010-post47.html (http://www.yachtforums.com/forums/16010-post47.html)
http://boatdesign.net/forums/showpost.php?p=81761&postcount=8 (http://boatdesign.net/forums/showpost.php?p=81761&postcount=8)

In fact you might find this whole subject thread interesting
http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner.html (http://www.yachtforums.com/forums/general-yachting-discussion/2701-trimarans-bladerunner.html)
_______________________________________________________
How strange...within a period of a week here we got messages from two fellows involved with the SeaKnife project. The second message came to my private email, and I inquired as to whether the two were the same person...no was the answer. So I'll post his message here as he may not be interested in participating in the forum, but his comments are worth repeating

I was privy to the Navy plans and special R&D with the original secret KNIFE BOAT PROJECT in 1981. It was a fast attack PT style boat that could be lauched rapidly to persue enemy subs. The design called for two deck mounted torpedoes, a 50 cal gun, and room for three men. Design specs also outlined top speed to be no less than 100 knots in a sea state five. It's a appears the that the Sea Knife project was swallowed up by the stealth boat's design team. Too bad, they were onto something with that boat.

message: Brian:
I read you an article you wrote about Peter Paynes Sea Knife. I was the PM at DARPA who fought hard to get Payne's 65' Patrol Boat built for the SEALs. I still have the water color of the B&W picture you published with your article.
I continue to believe this is the route the SEALs should go.

I got to ride in Peter's 32 footer and we were able to go through some 4' wakes at high speed. I'm guessing 60 kts +. The boat hardly responded to these wakes. I became a believer very quickly. His designs stand on their own and the resistance I met at DARPA, NAVSHIPSYSCOM etc. was WIH (wasn't invented here). Peter felt that the only solid patent he had was the bow transom.

SEALs don't get to decide that the weather is not nice. They have to operate under extreme conditions. As I recall, Peter told me that if a boat can manage a state III sea it could function worldwide about 30% of the time. If it could operated in state V it could function 85% of the time. This is the critical issue in combat.

The SEALs MK V experiences as much as 20 G's vertical accelerations. Hodgdon's Yachts composite MK V version may reduce it some, but not enough. As long as the Navy insists on a displacement design, this problem won't be solved.

peterAustralia

09-05-2009, 08:34 PM

I am a bit bemused as to why no one has mentioned the austal - grumman littoral combat ship, something scaled down from that might fit the bill. Maybe something in 60 to 70m range

My understanding is that 3 hulls has better ability to carry weight that 2 hulls, with everything else being equal

brian eiland

10-06-2009, 08:09 PM

daiquiri

01-08-2010, 06:56 AM

Note that there is very little spreading wake. In fact, it does not look like a wake at all, just foamy water from the water jets. Somehow, at 40 knots,you’d think there'd be more wake
That is an impressive lack of wavetrain!
I wonder why didn't they give her more flare up at the bow? I am thinking about it's seakeeping performance in high seas...

brian eiland

01-08-2010, 10:43 AM

...I wonder why didn't they give her more flare up at the bow? I am thinking about it's seakeeping performance in high seas...
The modern thinking is to not try and ride over the wave but rather pierce thru it. For that reason the top deck surface area is actually reduced up higher such as not to present a big area to the water that would force the bow down while piercing thru it.

jehardiman

01-08-2010, 10:48 AM

That is an impressive lack of wavetrain!
I wonder why didn't they give her more flare up at the bow? I am thinking about it's seakeeping performance in high seas...

You don't understand Navy thinking, i.e. littoral = no big waves. Only later will the need to cross seas or operate offshore continiously come into play. The design requirements only required max speed in SS 3, so if they used the maximum NATO envelope, that means 5 ft @ 8 sec.

Here is a quote from the press release of the sea trials of LCS 2.

Many of the test events were conducted in high sea-state and wind conditions (8-foot waves and winds in excess of 25 knots). Despite the weather, the ship repeatedly reached speeds of over 45 knots with propulsion and ride-control systems operating in full automatic mode, proving the effectiveness of the control systems and the highly efficient and stable characteristics of the trimaran hull form.

And the ship specs: http://www.ussindependenceship.org/overview_ship.php

8 ft waves = "high sea-state" :rolleyes:

kach22i

07-27-2010, 05:06 PM

Somebody built something similar to page one of this old thread:
http://www.youtube.com/watch?v=wnA6QTWvbCo&feature=player_embedded#!

hoytedow

07-28-2010, 03:00 PM

Somebody built something similar to page one of this old thread:
http://www.youtube.com/watch?v=wnA6QTWvbCo&feature=player_embedded#!Awesome video!

jehardiman

07-28-2010, 08:34 PM

Somebody built something similar to page one of this old thread:
http://www.youtube.com/watch?v=wnA6QTWvbCo&feature=player_embedded#!

I can't believe where the air intakes are...better not lose your hat back into one.

kach22i

07-28-2010, 08:57 PM

Who brought the marshmallows?

http://www.youtube.com/watch?v=fDjKRw6WZ2w&feature=related

Anytec1210

08-04-2010, 01:34 PM

Back in the days (late 80´s) when stealth was the really new and hot thing some really smart guys in Sweden put together the "Smyge" to prove the concept of a fast and capable attack and recon stealth vessel.

In 1991 the ideas turned out in this.
http://www.islandengineering.com/images/ses_mu2.jpg

A 27 meters (about 90ft) and 140 tonnes. Equiped with SA and SS missiles, torpedos and a 40 mm gun reaching up to 60 knots.

Since this was just a trial vessel they did not go into production but in 2000 those ideas turned into this.

http://blog.marport.com/wp-content/uploads/2009/10/untitled12.jpg

and today ..

brian eiland

01-12-2011, 06:37 PM

Doing a little exploring in Northern Fla today and ran across this projecr sitting out on the tarmac of an old airport just outside Green Cove Springs Fla

I say failed as I came back and looked it up:
http://www.metrojacksonville.com/forum/index.php/topic,9346.msg190847.html#msg190847

When I first looked at it I thought it might be alum construction with lots of fairing compound...but supposively it is all composite and hi-tech methacryalic adhesives

brian eiland

01-12-2011, 06:49 PM

That failed hovercraft was on the tarmac at Lee Airport in Green Cove Springs Fla on the St Johns river south of Jacksonville. It was a sight used to mothball a hugh number of vessels following WWII

http://www.desausa.org/images5/mothball_fleet_at_green_cove_springs.htm

http://www.metrojacksonville.com/article/2010-nov-exploring-clay-county-port-reynolds-park

Verytricky

01-12-2011, 07:34 PM

Here are some recent photos of the LCS 2 (to be USS) Independence .

blaaaaah etc

she’s strange looking but aerodynamically designed, is this beginning of a new design in ships?

Looks like a bladerunner on steroids

brian eiland

07-05-2011, 07:51 PM

Here are some recent photos of the LCS 2 (to be USS) Independence . She’s at 43 knots here running at half power. NOTE the absence of a bow wave.

Turns tightly, also; allegedly this also was done at 43 knots...and from the look of the small bow wave, she’s still in the turn.

And then we have the massive helo deck big enough for a CH-53. Last time I talked with the SURFPAC guys years ago.THIS was the LCS they liked because of the huge storage capacity under that flight deck and the size of the flight deck.

Note that there is very little spreading wake. In fact, it does not look like a wake at all, just foamy water from the water jets. Somehow, at 40 knots,you’d think there'd be more wake

But she has one drawback, she’s strange looking but aerodynamically designed, is this beginning of a new design in ships?

Austal, America’s newest warship-builder, is still scrambling to recover from the late-June revelation that the USS Independence, the Littoral Combat Ship it just built for the U.S. Navy, is “aggressively” disintegrating.

The 418-foot-long Independence (pictured) is slowly disappearing due to a process known as “galvanic corrosion,” where electrical current passes through a join between two different metals — in this case aluminum and steel — causing one of them to break down at the molecular level. Independence will be spending some time in San Diego for repairs.

The Navy has systems for dealing with galvanic corrosion, but did not include them in Independence’s design. And early on neither Austal nor General Dynamics seemed terribly alarmed at the omission. It’s possible they planned to control corrosion with rigorous, post-delivery maintenance procedures.

...more here:
http://www.wired.com/dangerroom/2011/07/plenty-of-blame-to-go-around-for-disappearing-warship/

BMcF

07-05-2011, 08:44 PM

Looks like a bladerunner on steroids
No comparison can be made; the two designs are wildly different.

(I've been involved with both in one way or another so I do know)

Verytricky

07-06-2011, 04:36 AM

No comparison can be made; the two designs are wildly different.

(I've been involved with both in one way or another so I do know)

Would love to know your involvement in either........ :rolleyes:

Comparison can be made: Looks like a Bladerunner on steroids. Quite a good comparison:

Both look like a monohull with two outer hulls stuck on about half the length along.

So when thinking very generally about boat style, you can say all tankers look the same, all cats look the same, all monohulls look the same: Thus all bladerunner type boats look the same in a general sort of way.:idea:

So a comparison between this boat and the bladerunner is obvious.

BMcF

07-06-2011, 07:47 AM

Would love to know your involvement in either........ :rolleyes:

Comparison can be made: Looks like a Bladerunner on steroids. Quite a good comparison:

Both look like a monohull with two outer hulls stuck on about half the length along.

So when thinking very generally about boat style, you can say all tankers look the same, all cats look the same, all monohulls look the same: Thus all bladerunner type boats look the same in a general sort of way.:idea:

So a comparison between this boat and the bladerunner is obvious.

A visual one perhaps.

The Austal vessel is essentially a full displacement super-slender monohull that is 'stabilised' in a static stability sense by the two small ama hulls to either side.

The Blade Runner is a fully planning hull with air-entrapment features built in to the bridging structure to the outer hull extensions; said extensions also providing lateral stability in turns.

BMcF

07-06-2011, 07:50 AM

Would love to know your involvement in either........ :rolleyes:

.

Do you routinely cast aspersions like that, hinting people you have not the foggiest idea about are liars? Odd behavior, that.

I'll sit back and see if some on here who do know my 25-year track record in HPMV design, construction and trials chime in instead of wasting my own energy in a reply right off the bat. ;)

Verytricky

07-06-2011, 08:42 AM

Looks like a bladerunner on steroids
A visual one perhaps.
Yes - that is the whole point of using the words 'LOOKS LIKE' - If I thought it was a planning hull like the bladerunner, perhaps I would have said something along the lines of 'goes like' or 'handles like' - but no - I decided it looked like a blade runner. And it does.

I'll sit back and see if some on here who do know my 25-year track record in HPMV design, construction and trials chime in instead of wasting my own energy in a reply right off the bat. ;)
Too late, you replied twice!
And why would I need someone who knows you have 25 years experiance to tell me that you are correct and the boat does not look like a blade runner, when you have already said it does!!

(I've been involved with both in one way or another so I do know)

Do you routinely cast aspersions like that, hinting people you have not the foggiest idea about are liars?

I think I have a fair idea of everyone who had been 'involved' in the blade runner, from the designer, testing team, builder, design owner, and most of the people who have owned or raced one. And I dont see you in that list. So you may have 25 years of experiance, but I dont see your 'involvement' in the bladerunner being obvious to anyone, so thus I invite you to tell:

Would love to know your involvement in either........

So please tell, so I can learn......

Some people have 25 years experiance, and others have one year experiance 25 times......

BMcF

07-06-2011, 08:45 AM

Some people have 25 years experiance, and others have one year experiance 25 times......

Indeed. :D

BMcF

07-06-2011, 08:50 AM

I think I have a fair idea of everyone who had been 'involved' in the blade runner, from the designer, testing team, builder, design owner, and most of the people who have owned or raced one. And I dont see you in that list. So you may have 25 years of experiance, but I dont see your 'involvement' in the bladerunner being obvious to anyone, so thus I invite you to tell:......

No, "invite me to tell" is not what you did at all. I can read. Although, it was actually the rolling eyes emoticon that probably underpinned the meaning you intended.

There was a time....when we provided craft design and construction support to an outfit headquartered in Hawaii. An 'early' Bladerunner was one of the vessels in that mix of craft under testing and evaluation. I count myself forunate that I was not on board the day it was rolled at nearly 60 mph in flat calm water. One of my counterparts still carries the scar from the stitches he received.

Not one of my favorite craft.;)

keysdisease

07-06-2011, 08:51 AM

Atlas Hovercraft, I watched that critter grow from the ground up. Actually a USCG approved 150 pax vessel, all composite. Used a way cool polymer planking system for the deck.

The most unique concept was the construction process. It went together very fast with a pretty small crew and no real equipment other than a big forklift. Used a mold to make segments that glued together.

Here's a little more:

http://www.dejongandlebet.com/996_AtlasHovercraft.htm

Steve

Doing a little exploring in Northern Fla today and ran across this projecr sitting out on the tarmac of an old airport just outside Green Cove Springs Fla

When I first looked at it I thought it might be alum construction with lots of fairing compound...but supposively it is all composite and hi-tech methacryalic adhesives

kach22i

07-06-2011, 09:25 AM

http://www.wired.com/dangerroom/2011/07/plenty-of-blame-to-go-around-for-disappearing-warship/
Perhaps, but when? Austal and General Dynamics manufactured Independence as a team, using Austal’s Mobile River facility. But once the ship entered Navy service, maintenance became General Dynamics’ sole responsibility. Then in early 2010, the two companies ended their partnership. And a few months later, the Navy settled on Austal and Lockheed as the prime LCS builders, effectively barring General Dynamics from ever getting a piece of the small-warship pie.

Looks like General Dynamics got the last laugh to me.:mad:

RE: Atlas....................from a recent post in the HCA forum I made.
http://hoverclub.invisionzone.com/forum/index.php?showtopic=2118

http://www.metrojacksonville.com/forum/index.php/topic,9346.msg190847.html#msg190847

HoverCapt
Newbie

Posts: 1

Re: What happened to Atlas Hovercrafts?
« Reply #38 on: March 16, 2011, 09:13:06 PM »
Well Hello
I realize I am coming into this on the tail end of things. I ran across this thread to and felt the need as a ex Atlas employee to put in my 2 cents. I followed this project from the beginning 2 years into it I became part of it. Feeling the need to set the record straight here.

Let me start by saying that the bigger picture for this project has been missed. We did not in any way think we would be the only option for travel up and down the river. We simply wanted to provide another choice to the public to make the trip. Getting even a small portion of the people that make the trip off the roads would decrease the amount of traffic on our roadways. Based on the operational cost studies, it would have been very affordable for the average person to make the trip. As for the environmental issue concerning the manitee, there is no part of the craft the travels through the water once the craft is on hover. Understanding the way the craft operates is key in any project moving forward concerning a hovercraft. All studies completed proved that the craft would actually be a positive impact on our river. (JTA has completed 2 studies).
The second part of this is Jacksonville river system was not our only focus. Looking at a bigger picture this size craft is more suited to run near coastal waters, which is why it would have been put into operation between Miami and the Florida Keys. This was no secrete and most people that where involved knew this. JTA or any other Company that was interested in learning what the project was about was given the information concerning the possibility of smaller craft. It was the intention to build the proper size craft for the job.
Now to answer the question that has inspired all of our input. Atlas closed it doors to it's employees in May 2008 due to the lack of funding. Even though hovercraft have been around for over 60 years there still those of us that do not understand the concept of it, proven by the earlier conversation. As for Kurt Peterson, it is my understanding that he is still in the area and has moved forward to other hover possibilities. Abandoning the Atlas craft to decay where it sits.

BMcF

07-06-2011, 09:34 AM

[Looks like General Dynamics got the last laugh to me.:mad:

]

You might be correct.

What I cannot for the life of me fathom in that whole corrosion debacle is why standard off-the-shelf active corrosion control technology was not included right off the bat in that design. Its been around and in use in aluminum vessels for quite a while, including others built by Austal. The USN Sea Fighter catamaran was designed and built including an extensive active corrosion protection system...and that was in 2002-3. :confused:

Wavewacker

07-20-2011, 07:11 AM

Hi, first, Ihave not read the entire thread. It began with a stealth recon boat and even though it has become a hovercraft issue, all well and good, my comment is that what you began with what appears to me to be a gun boat concept, not a recon asset.

Recon are small unit ops and frankly don't need stealth protection from radar as these boats (RIBS) are usually small enough not to be of any concern. Larger RIBS, 40' are designed to be fast enough that in the event of detection they move fast enough to reduce any chance of hostile action. Usually for insertion, not recon.

A gun boat or patrol boat has a different mission, patrolling is not an offensive mission.

If the OP wants to design something for military use, you first begin with a well defined purpose, specialized mission performance with relevant tactical issues addressed. You don't design a boat or any vehicle and then decide what mission or use it may have.

Cool hovercraft, a hovercraft or airboat is not allowed on any Missouri waterway, when I asked why, I was told that they are difficult to control and would be a hazard, so not allowed on the rivers or lakes. :mad: I'd like a small one!

kach22i

07-21-2011, 04:23 PM

Cool hovercraft, a hovercraft or airboat is not allowed on any Missouri waterway, when I asked why, I was told that they are difficult to control and would be a hazard, so not allowed on the rivers or lakes. :mad: I'd like a small one!

I have no idea who told you this, and doubt that it's true.

The Mississippi River has been flown up and down by hovercraft for a long time. The former owner of largest plan and kit supplier of hovercraft (Universal Hovercraft) as I understand it lives near there.

The problem I've read about is on the Mississippi, is that the scale, size, speed, direction and strength of barge wake waves is hard to judge.

http://www.hovercraft.com/content/index.php?main_page=index&cPath=147
Universal Hovercraft hosted a cruise at Bob Windt’s house on the mighty Mississippi River June 18th and 19th. Cruisers began showing up Friday afternoon in preparation for Saturdays cruise to Savanna IL. Nineteen hovercrafts departed Cordova Saturday morning. Eighteen hovercrafts made it to lock and dam #13 in Fulton Illinois. After locking through we headed north to the Palisades Park. Seventeen hovercrafts made it to the park. Some took time at the park to rest while others went on a hike.

Some lakes and rivers limit horsepower to help control wakes (speed) and noise. These limits apply to wake-less hovercraft as they are registered as watercraft.

http://firstresponseteam.blogspot.com/2008/06/june-20-2008-clarksville-mo-flood.html
June 20, 2008 - Clarksville, MO Flood
http://3.bp.blogspot.com/_l08aW7hYELY/SedjVWmAbXI/AAAAAAAAAHc/I2ehts5CxDk/s320/MO+1.jpg
By the time we arrived, we discovered that it was a false alarm. I called the capital to alert them, and we realized someone had their information wrong. As far as I was concerned, it was good news. At this point, the Mississippi was raging and had shown no mercy for the many cities left in the wake of its destruction. I then heard about a community just a few miles north that was in need of a hovercraft to help monitor levees and check the river levels. We left within the hour for Clarksville, MO.

Wavewacker

07-25-2011, 07:02 AM

Hi, I read the article and didn't seem relevant to the post, it was a water patrol officer who did the inspections for home built boats and he was specific about a hover crafts not being licensed in Mo. On the old muddy, any boat tagged in any ajacent (or any other state) can be moored on the Mo. side. In times of disater I doubt any military or other "official" search and rescue vehicle is subject to the rules for civilians, if someone is assisting officials I don't see some WP Officer writing any tickets. Something about "selective enforcement". Then again, it could be the WP Officer was having a bad day and didn't want to fool with it or look anything up, just saying no! Just passing along what I was told. :D

If it's really important, I'd suggest you call Jefferson City and ask, or look up the statutes on registration of water craft.

kach22i

07-25-2011, 09:07 AM

If it's really important, I'd suggest you call Jefferson City and ask, or look up the statutes on registration of water craft.
Did you look it up before posting this information/misinformation?

Wavewacker

07-25-2011, 10:33 AM

Nope, not at all! As I said, just passing along what I was told. May be it's the tone I used in pointing out the opinion of the military viablity of designing a boat for "RECON" that was not appreciated that prompted this issue, don't know, I was not meaning to be rude about it.

I have over fifty years of experience on Mo. lakes and rivers and have been on every lake in the state of Mo. and I have never seen a hovercraft on the water, never heard of any accident involving a hovercraft on Mo. waters, never saw one in any boat yard, boat dealership or on any trailer going down the highway. I have been on most of the rivers as well and with the same experience. Having property at Tablerock Lake and being in the community, I just can't recall any fish stories involving any hovercraft.

There is no horsepower limitation on Lake of the Ozarks or Tablerock Lake, so if anyone had a hovercraft with whatever horsepower you'd like to assign, horsepower would not be the reason for a hovercraft not being used.

Aircraft are allowed to take off and land on the two lakes I just mentioned, but then that is an FAA issue and not a hovercraft.

That certainly does not mean that unicorns do not exist in Mo. I'm sure someone could own one. Could be they own one and use it on their own land and private lake or pond, exempt from registration or if registered for personal tax purposes, not used on public waters, I don't know.

If I were more computer savy, I'd go to the statutes and post them, right or wrong, I really wouldn't care.

Obviously you disagree with my opinion based on an out of state factory, the use of hovercraft on the Missippippi and an emergency situation, perhaps other reasons. The factory mentioned is in Il. not Mo., the Missippippi is not just a Mo. waterway. I think what I said was "Missouri waterway", meaning in the state not along the boundry of the state, but you'd be correct in saying that along the shore of that river is under Mo. jurisdiction. Along the Missippippi, there are exceptions to Mo. registration requirements. No, I didn't look that up either, it's common knowledge and inline with maritime regestrations I believe, as recepricol agreements with other states as well as being exempt for non-residents.

And,this is really off topic, it was just a comment based on what Mo. law enforcement here had told me.

All I can say is "show me"! LOL (Mo. is the Show Me State)

kach22i

07-25-2011, 02:25 PM

And,this is really off topic, it was just a comment based on what Mo. law enforcement here had told me.
LOL; I think that I know the guy you talked to, he used to hang out in a bar in Boston called Cheers, and his name is Cliff Clavin.:D

I do remember St. Louis Hovercraft, they gave rides and made skirts.

Found this, scroll to last page. Hovercraft and Airboats even have their own code.

http://dor.mo.gov/forms/Missouri_Titling_Manual.pdf

Same goes for this repossession form.
http://dor.mo.gov/forms/5005.pdf

Why would they have things on the list which they do not support? They would not, pretty simple.

I cannot find that which does not exist. Feel free to do your homework.

http://dor.mo.gov/motorv/watercraft/

I know there are hovercraft in MO, they are not unicorns.

http://hoverclub.invisionzone.com/forum/index.php?showtopic=2450
[quote name='Hovermaster' timestamp='1311603835' post='23911']
Tell him to ignore people who obviously have no clue. There are no licensing restrictions on hovercraft in Missouri. I had my craft registered there and there are a number of club members who live in Missouri, all of whom use the rivers.

Here is the HCA events schedule link, might be something near you.
http://hoverclubofamerica.org/content.aspx?page_id=2&club_id=831743

The Hoverclub of America has ambassadors all across the nation, the list is currently down but scheduled to be back up soon.

The old and out of date list has this:
http://hoverclub.invisionzone.com/ContactUs/Ambassadors.html#Missouri
MISSOURI

Gary Lutke H-2475
Laurie, MO
(561)-274-2247
Gary@hovercraftdepot.com

Again, not current and neither is this:
http://www.facebook.com/pages/St-Louis-Hovercraft/204944635254?v=info#info_edit_sections

Say hello to Cliff for me.:cool:
http://www.motifake.com/image/demotivational-poster/0912/cliff-clavin-on-beer-reprint-of-a-classic-diatribe-from-chee-demotivational-poster-1260903243.jpg