Vessels with suspension

[JonathanCole]

Is anyone aware of any attempts at designing or building vessels with articulated suspension? I suppose that hydrofoils could be considered suspension of a sort, but I was thinking more along the lines of control arm/ spring/damper as commonly used in automotive applications. I would imagine such forms of suspension would have a much longer throw in order to accomodate waves and would therefore have to be very low-mass, light-weight devices. Clearly, there could be many forms of compressed-air motion damping. There could possibly be energy generated from articulated suspensions. I searched suspension on this forum but came up with nothing like a wave-motion suppressing suspension.

[yipster]

hi jon, you must have forgotten http://www.antrimdesign.com/powerboats/88.htm
there are some better pics somewhere on the forum showing the hinging hulls and propulsion

[duluthboats]

Jonathan,
Something like this? http://wam-v.com/
Gary

[duluthboats]

Yipster
LOL!!! Yes great minds do think alike. ;-)

[kach22i]

Some good information posted in this foil thread:
Surface Piercing Foil Damping
http://boatdesign.net/forums/showthread.php?t=21853&highlight=foil

.......................................

Simple - the business end (page 86).
http://boatdesign.net/forums/showthread.php?p=187737#post187737
How do you get into this seat? Does it swivel?
http://www.safehavenmarine.com/GENESIS%2037%20development%20page.htm
http://www.safehavenmarine.com/IMG_8595.jpg



http://boatdesign.net/forums/showthread.php?t=11052&page=87
George,

Those marine helm seats can cost between $2,000 - $3,000; they have a shock absorbing mount with up to 6" of travel, lateral movement, and flip up armreast.

SafeHaven's designs seem really at home in the heavy stuff. I watched some of those videos on their site. Throw the boat into Force 11 winds, 20' seas before delivery. They must be pretty confident everything will hold together.

Great site, neat photos and videos. I want one!

[JonathanCole]

hi jon, you must have forgotten http://www.antrimdesign.com/powerboats/88.htm
there are some better pics somewhere on the forum showing the hinging hulls and propulsion

Sure, I remember the Proteus. I wonder why there is still no performance data. Also why a cat with 100 foot long hulls, 16 inch draught, (that can't plane, because the hulls flex, would require 2 - 355 MHP diesels? I also wonder why the cabin sits so high. Maybe the flexing of the suspension is extreme, or maybe they are planning for 15 foot seas.

[rambat]

The USHIKIRO, built at Mitsubishi Heavy Industries yard at Shimonoseki was delivered in October 1987 to shipowners Higashi Chugoku Ryoju Kosan, a subsidiary of MHI itself. It is the first hi-stable cabin craft (HSCC) in which the cabin is connected to the main catamaran-type hull by a computer-controlled suspension system and shock absorbers, designed to absorb oscillatory wave motions and the impacts caused by high-speed motion over waves. Apart from its use in high-velocity craft, the builders envisage applications in passenger research vessels. Principal particulars are: length oa 12.7m; breadth, mld 5.4m; depth, mld 1.85m; gross tonnage 17t; deadweight 2.6t.

[kach22i]

I cannot find any photos of it.

Is the spelling correct?

[rambat]

It was also a vessel named Voyager see:

http://translate.google.com/translate?hl=en&sl=ja&u=http://sts.kahaku.go.jp/hitnet/index.php%3FPMode%3Ddafault%26s_and%3D%25B9%25F1%25CE%25A9%25B2%25CA%25B3%25D8%25C7%25EE%25CA%25AA%25B4%25DB%26s_or%3D%26s_not%3D%26APage%3D659%26PSize%3D10%26PMode%3Ddafault&sa=X&oi=translate&resnum=7&ct=result&prev=/search%3Fq%3DHigh-Stable%2BCabin%2BCraft%26hl%3Den%26rls%3DGGLD,GGLD:2005-13,GGLD:en%26sa%3DX

[tom kane]

Would you believe?? about 1945 I saw movies of a ply cabin boat experiment using large water skis attached to the hull.It went very well over wakes and against a head sea.I have never seen the likes again,except for a local ferry running on foils 1950`s.Which was never very successful.Damaged foils and many breakdowns.

[Trevlyns]

On a much simpler scale, the 8.5 meter Pacific proa I designed and am busy building will have an "independently sprung" small hull (Ama). It will basically pivot from the centre on a nylon bearing and be "sprung" with strong bungee chord to both ends. I'm hoping this will eliminate twisting torque on the beams and allow the smaller hull to act independently from the main hull.

No idea how it will work in practice, but it's so cheap and simple I have nothing to lose basically.

[yipster]

http://www.ulstc.org/images/Amaryllis.jpg
http://www.ulstc.org/Herreshoff.html
have to re-read tho if there where any springs loaded in amaryllis

[rambat]

Here is the early demo HCSS, sort of self explanatory 2 pages. This is what the thread started out looking for I think, knew it was in old Jane's. I have been involved in the design of some very fast US Navy boats. One design has been serving as a special operations boat for about 15 years. As such the long term effects are beginning to take a toll on the operators. Compressed spines, bloody urine and a sort of "Punch Drunk" condition after harsh and fast sea transits, common in offshore racing but it is a serious disability for war fighting. So in an effort to offer solutions to this human factors issue I have resolved the following conclusions which I offer up for discussion.

1. Hydro/pneumatic articulated cabins by their nature introduce structural point loads and their associated structural weight penalty makes takes them out of contention for a fast boat.

2. Suspension seats only dampen vertical accelerations in a narrow sea state band.

3. This "human factors" limitation will forestall any performance improvements in manned fast boats until it is solved.

4. A tremendous amount of good development has been poured into SES ride control systems (RCS) and the results have been applied to Catamaran and Wave Piercer ride control systems. Without these ride control systems every existing multihull fast ferry since 1985 would NOT be able to ferry people.

5. That mature RCS technology could be tapped for very fast monohulls but only by some other means than the multihull solution of using a submerged, dynamically actuated foils due to the parasitic drag penalty.

6. A cabin supported primarily on an air cushion, within a conventional monohull, will spread its "suspension loads" across the generous amount of air cavity surfaces.

7. General position of the cabin in relation to a hammering 100 mph hull :) can be handled with cris-crossing alignment tethers.

This "cushion-isolated floating cabin" can then utilize the deep well of RCS control algorithms and adapt the same venting hardware!

Sounds to good to be true, what am I missing?

See attached conceptual schematic.

[Ramius41]

Try this one on for size!.. http://www.airboats.fi/

[Guillermo]

An interesting article on the rules about shock mitigation on high speed craft:
http://stinet.dtic.mil/cgi-bin/GetTRDoc?AD=ADA446789&Location=U2&doc=GetTRDoc.pdf

A couple of interesting presentations:
http://www.highspeedcraft.org/pdf/3Dobbins_Human_Factors_Issues.pdf
http://www.highspeedcraft.org/pdf/4Peterson_HSC_Biodynamics_Human_Performance.pdf

Cheers.

[Guillermo]

Present 'suspension' vessels.
Stephen, what speed are we talking about?

Cheers.

[kach22i]

This "cushion-isolated floating cabin" .............

Sounds to good to be true, what am I missing?
I keep catching myself thinking in single or two directional forces, rather than 3D forces or forces over a period of time.

How would a chamber of air under the cabin dampen the vertical acceleration (in the UP direction)? Would not the air chamber be better if it were a sphere around a sphere or operated as a gyroscope?

Tethers?

I also keep thinking that jet aircraft style "G-suits" which keep blood to the brain may be able to play a role, but have no science or research to back up that random thought.

[warren mosler]

Applying my automotive experience to displacement hulls:

The water already acts as a spring, and the hull shape determines it's rate of increase as it moves vertically.

damping could be done by underwater horizontal 'ridges' but with a drag penalty.

The ratio of sprung to unsprung weight determines the degree of ride control in a simple spring/shock setup. This is the awkward part for a boat, as simply suspending a seat is totally backwards in this respect, for example.

In a car or truck, there's no substitute for wheelbase for ride quality. In this respect a boat hull is like a snow board going over a bump vs a skate board going over a bump.

To replicate the ride of a long wheel base car would require a boat with the floatation fore and aft, with as much 0 floatation in between as possible.

This has other issues, such as getting sufficient displacement with a reasonable draft and reasonable length to beam ratios. Seems impractical for most missions.

Best I can think of is something like two displacement power cats in tandem with a long deck maybe 8 ft off the water line separating them with the cabin on it.

[yipster]

Guillermo, pic 5 in post 10 is a SWATH (http://www.boatdesign.net/forums/showthread.php?t=1178&highlight=swath) ride yes ?
http://www.budweiser-beer.net/beer_images/solar_navigator_rc_model.gif

[warren mosler]

Yes, does what it does reasonably well, same with 4 hull 'slice' which rides a bit better, i'm told, due to the 'long wheelbase' effect i describe above, maybe.

both forms have deep drafts and relatively high drag at speed, with speeds above 20kts problematic, also due to propulsion issues?

Anyone seen a 'four footed' surface craft? The 'stability yachts' prototype moves some in that direction but doesn't try to max the 'wheelbase'?

http://www.stabilityyachts.com/

[kach22i]

An old post of mine (Hovercraft):
Mar 29 2007, 02:29 PM
http://www.hoverclubofamerica.org/forum/index.php?showtopic=1098&hl=spider
[quote name='kach22i' date='Mar 29 2007, 02:29 PM' post='9636']
The Jesus Boat
http://www.hoverclubofamerica.org/forum/uploads/1174494220/gallery_181_7_20902.jpg

EDIT: Link to larger image
http://www.hoverclubofamerica.org/forum/in...si&img=1019 (http://www.hoverclubofamerica.org/forum/index.php?automodule=gallery&req=si&img=1019)



.............................................................................................


[quote name='kach22i' date='May 17 2007, 12:57 PM' post='10628']
UPDATE 05/17/07

.........AND I THOUGHT MY IDEA WAS TOO WEIRD TO PATENT!

Spidercraft
http://www.google.com/patents?id=vCkeAAAAEBAJ&dq=5592894
Abstract
This is cool too, from 1940.

WATER SPIDER
http://www.google.com/patents?vid=USPAT2347959

Check out Figure 5.

[yipster]

computer controlled thats all very well possible kach22i
saw a mountain climber car in an old popular mechanics once like in fig 5
looking from the top i wonder why there are no whisbones used
samples are older and for a hoover patend spider i'll bet it only cost ya
but thanks for showing, nice one i missed before :cool:

[yipster]

http://www.stabilityyachts.com/images/Image7.jpg
and Warren, how much i like stabilityyacht (and swath) i'll keep thinking of wanting a sail...

[rambat]

Yipster, I am the designer for Stability Yachts"yacht version", thanks for your kind words about the prototype craft. It is possible to make it sail propelled and could be considered since the drag is like a catamaran when pumped up, Hmmm.
Interest has been strong with the recent press we have garnered around the new Stability 63 yacht, If we get a deposit to build it I will probably pour any profits into research for other better riding craft, especially small-high-speed craft. Years ago when boats started going to fast for safe human factors I was thinking about something like the Longbow concept attached. It may be a small concept, like a rough water dirt bike. In larger designs this could take advantage of the "flexibility" in the structure, like the aero elasticity in jumbo jet wings. That flexibility may allow the hard points on the shock absorber to stay attached. Way fun riding I am sure! Great concept Kach, I have a "Cache" of old concepts from Bell Aero with some offshore stability ideas for hovercraft, when I get time to scan them I'll post them here.

[kengrome]

There are simpler ways to reduce vertical acceleration in boats, it's just that the buying public doesn't like the looks of such boats ... and/or the designers and builders of today choose to ignore the proven techniques of the past.

Take a look at the Seaknife designed several decades ago by Peter Payne:

http://www.yachtforums.com/forums/attachments/technical-discussion/9086-trimarans-bladerunner-seaknife1.jpg

Mr. Payne was a genius mathematician (http://ourworld.compuserve.com/homepages/graeme/Peter/prpatent.htm) who understood how to make a high speed planing hull that substantially reduces the vertical accelerations that injure people. The boats plane on narrow flat triangular bottoms and their bows are so sharp that they slice smoothly into waves as they meet them, dramatically slowing the boat's vertical acceleration compared with virtually all other planing hull boats.

http://www.yachtforums.com/forums/attachments/technical-discussion/12382-trimarans-bladerunner-seaknife4.jpg

The planing craft only planes on a small portion of its bottom at high speeds. When such a craft encounters a wave, the lifting area is greatly increased and the craft experiences the upward acceleration which is the most marked feature of pounding. Because of the inertia of the water in the wave, the magnitude of this acceleration is much greater and would be calculated simply from the increase in wetted area. Thus, the problem which exists is derived from the fact that most planing craft have planing surfaces which are much too large.

The present invention provides a high speed boat with a planing hull which is not subjected to pounding in waves but cuts through the waves, thereby giving the boat an amazingly steady level ride. The boat is not only efficient at high speed but has excellent seaworthiness at low speed due to its low natural frequencies in roll, and pitch. At high speed, the boat is stabilized by spray sheets thrown up that contact the hull sides.

Maybe it's time we took a look at the past, and use the simple solutions proposed decades ago, instead of complicating everything with the typical high-tech solutions of today.

[kach22i]

I've seen the SeaKnife posted in these forums before, but never quite in this context or certain perspective.

Cool contribution.

[kach22i]

Took 4 years but I've been one upped.......nice job too.

http://sketchup.google.com/3dwarehouse/details?mid=1a968c2c374c8a3e70d45c28bef72613

[CaptBill]

How about a moon pool suspension system? You get as bonus features 1.generator (piston driven) 2. air conditioner 3. Dampening suspension. Super simple and potential for no moving parts (designed as a simple an 'air pocket' under the water line).

Noah's Ark appears to have had this feature.

[kach22i]

How about a moon pool suspension system?

I'll Google anything...........is the MoonPool?

Experiment Research on Flow Noise and Hydrodynamics Character of Moonpool
http://www.latest-science-articles.com/Technology_Science/Experiment-Research-on-Flow-Noise-and-Hydrodynamics-Character-of-Moonpool-16618.html

It's twisting my brain and giving me a headache.:D

Patent:
Moonpool guidance system for floating structures
http://www.freepatentsonline.com/4512409.html

[CaptBill]

The idea is simple.

Cap the hole in the moon pool at, say, deck level. Now massive amounts of air pressure/suction is collected in the hole. The weight of the hull as it rises an falls with the waves creates a constant compression/suction force.

The idea is to collect the energy in a hydraulic system . When you are 'consuming' this energy you will have a dampening effect because the relative height of the piston (water level) is being slowly 'deflated/inflated', creating a dynamic alteration in the motion.

Amazingly simple concept.

[kach22i]

Amazingly simple concept.

Are there any real life working models or examples of this which you can share?

[CaptBill]

http://www.barry.warmkessel.com/windsor2.html

This is the link to the mans page that figured this all out.

The Ark was no joke. It was/is a engineeing marvel beyond compare.

[CaptBill]

A simple experiment:

Take a plastic cup, put a small hole (an orifice) . Press it in a sink with water below the waterline slowly (speed of a wave). Pull it up slowly. Simple. The simple orifice now function essentially, just like a shock absorber. The hull is also 'glued' down to the water by suction force. This should dramatically change the motion. This effect is easily varied/throttled by merely adjusting the orifice size.

[CaptBill]

http://www.latest-science-articles.com/Technology_Science/Experiment-Research-on-Flow-Noise-and-Hydrodynamics-Character-of-Moonpool-16618.html

I think this study/analysis is a good find. I don't fully comprehend what is said, but this is certainly helpful info for actually designing a moon pool, looks like.