sub build underway christmas 2011

The modern technology was nukes.

 

Yeah, I knew that.

 

The only submersibles like this I have seen were used by drug smugglers out of South & Central America. They use them to evade surface radar. Aside from risky (and illegal) drug missions, I just don't see any practical civilian missions for a submersible like this. The glory of sailing is on the surface...all the waves, wind, clouds, sunsets, birds, beaches, babes, etc.

Then again, you might find a nitch market for whale watching if you installed some nice viewing portals. Just be sure the egress system is 100% tested. Such a device could be a death trap.

 

The German U-boats and American diesel boats ran the diesel on the surface where they could get air for the motor easily. Underwater they ran batteries if they wanted to be quiet. They also had a snorkel to pull in air for the diesel if they did not submerge too far.
The batteries were not very large and old tech so they were really limited on speed / range.

Also the pressure hull of the old subs was cylindrical, similar to modern subs, but they had decks and superstructure that helped run on the surface, and they floated higher than a modern sub which also helped lower resistance on the surface. The also had lookout towers, bridge deck with railing, and a deck gun which adds drag underwater.

Take a look at a modern "teardrop" shaped sub on the surface and look at the huge wake - easily 3-4 times the width of the boat - when they have any speed. That represents high drag on the surface. There is nothing left on the deck, the sail is completely streamlined (similar to a proper rudder shape).

The immense difference in available power between a Nuclear plant and a diesel electric boat also makes a comparison completely uneven.

Marc

 

very true--people die all the time in yacht races...and sialing voyages so- i dont see the risk factor being all that muich different- but hey thats me...

 

If its done right it should be fine for shallow dives--my intentions are not to take it to anything over(under?) 200 ft...nowadays drugs smugglers have essentially abandonded subs as a way to run drugs--now they use a tethered sinking tube whcih can be released by the boat towing it sink and then be retreived later...its better and cheaper than complex sub designs for drugs--that period in history-where subs and drugs go together is more or less done...I see using this lnot for missions but for the joy of three dimensional travel in the water..enjoying both the yacht lifestyle and the underwater nemo style.

 

Hey Marc- you touched one a really big point--it was very hard to decide on the nuke design--i really wanted a surface running sub for civil purposes. The type XXI was ideal and it helps to run under the surface but--the idea now is that the sub actually runs just under the surface being very efficient teardrop--it acts the same way a bulbous bow does on a ship--just below the surface it is highly efficient and the sail is what cuts the water like the bow of the ship..
so i did a second version of my design with a model bow, and designed the sub to run on or below the surface. since i dont expect nuke speed the compromise of a model bow is negligible- the subs designed speed is around 7 knots slightly submerged on diesel power, and about 3 knots - or slightly more running on electrics. based on the best info i could collect.

 

I posted this on the other thread related to this project, but it's perhaps worthy of being here instead, now that the other thread has closed down.

As someone with some time in submarines on trials work, I'd say you really need to balance some of those points and look at them a bit more closely.

The risks are considerable, from unknown hull structural flaws causing hull rupture (even 200 ft is over 6 bar), through the issues associated with scrubbing unwanted gasses from the internal atmosphere in a controlled way, through to the very considerable technical challenges in making hatches and ports secure and leak proof without introducing stress raisers in the pressure hull. There are good reasons for boats having cylindrical pressure hulls with a teardrop non-pressure hull casing around the outside - worth considering, as it's damned hard to make a tear drop shape with good and known structural integrity, even for operation at just a couple of hundred feet.

Some of the pluses up in that list aren't quite right, either. Subs give a pretty nasty ride unless they are running below the wave affected zone (which means being around 20 m or so down, more if it's really rough). They have limited reserve buoyancy (in the UK we design for being able to surface with one flooded compartment, the old Soviet boats didn't even have this much reserve, hence, in part, their high serious accident rate).

Navigation is challenging. The INS required needs to be very sophisticated to give you a reliable nav system when you can't access GPS, LORAN or whatever because your submerged. Dead reckoning is very difficult, because sub-surface currents are rarely known or marked accurately on charts and they vary wildly from surface currents (they will often be in the opposite direction even).

Attitude control is far harder than it seems and is critical for operation close to shore, even on a 50ft boat. It's quite possible to have the bow or stern hit the bottom from vigorous trim changes, for example, and a sub has a high polar moment so once swinging wants to carry on.

Also it's possible to get a submarine out of pitch trim to the point where it cannot recover back to the surface from an over vigorous nose-down plane angle. What happens is that the rate of descent can result in a pressure increase that the tank blowing system cannot keep up with - meaning you keep on going down unless you have enough plane authority to pitch back up - the planes then become highly safety critical.

As for "seeing more underwater" I guess you've never been at depth and tried it! Suffice to say that down below a few tens of metres the vis is crap as a general rule. Around this part of the world, even in shallow water, the vis rarely exceeds a few metres.

I should add a qualifier - I absolutely hated being in a submarine, so much so I once paid my own air fare home rather than go back to the UK on the boat. It colours my views a bit...........

 

No doubt their risky. It seems ever year or so a sub goes down and the crew is trapped. Rescue operations for these subs often involve specialized submersibles (very expensive & dangerous operation to rescue).

Some questions:

Q1: What sort of system on this submersible/sub will prevent it from sinking if the hull ruptures for some unforseen reason? Can you make it float if the hull breaches and fills 100% full of water?

Q2: How can you escape if you are plunged to unforseen depths?

Q3: How do you communicate with the outside world if you're trapped at the bottom of the ocean or lake?

By and large I feel most are truly concerned about your safety.

 

Making a sub float is damned hard if it has any sort of hull breach. One really big problem is the pressure needed to provide buoyancy. For example, say the boat had a hull breach at 200 ft. The pressure outside is around 6 bar, the pressure in the boat will be around 1 bar. If you pump air into the boat to keep the water out and retain buoyancy you'll harm the crew, as 6 bar is enough for air to be toxic, plus you'd have problems with nitrogen narcosis to deal with.

If you make the ballast tanks big enough to have sufficient buoyancy when blown that they can cope with a flooded compartment then you increase the hull size a lot. You also increase the compressor and air bottle size (bearing in mind that the air blowing the ballast tanks has to be over 6 bar to force water out at 200 ft, so has less volume). You then have to have buoyancy compensation to flood the ballast tanks progressively as the boat come up - it sounds counter intuitive but the air expands as the boat rises, increasing buoyancy and making the boat rise faster. Failure to control the rate of rise will result is a pretty spectacular (and potentially damaging) breach (think Seaview from the TV series "Voyage to the Bottom of the Sea").

The same thing can happen in reverse when diving. Diving with no propulsion is fraught, as it is very tricky to dive by just balancing buoyancy. As you flood the ballast tanks and the boat starts to go down the pressure compresses the air in the tanks and reduces its volume, and hence buoyancy. The result is the boat wants to dive faster, driving a vicious circle. One of the most hazardous elements of sub-polar submarine work is surfacing in the arctic, where the boat has to go up and down through the ice vertically and can't use forward motion to gain hydrodynamic trim. It can take tens of minutes to surface and dive, because of the need to very finely control buoyancy when diving (surfacing speed is limited to break the ice gently).

 

Tugboat,

Look at the teardrop shape surface running photos if you are planning to run with just the conning tower out of the water. This is almost the worst you could do as far as drag. The entire volume of water displaced will be pushed to the surface and cause a huge drag. This is similar to a hydrofoil, you need to be well beneath the surface to get the benefit of the modern shape.

You might want to consider Jeremy Harris's post, everything he has said matches the information and (limited) experience I have.

Have you see the heavier-than-water sub that someone is developing? It depends upon lift from "wings" and propulsion for comming up from a dive. I don't really know how they stay at the surface for extended periods of time, but this seems like a really interesting alternative resulting in a smaller sized vessel. The only difference between this and an airplane is that the airplane comes down to earth with loss of propulsion (often a very hard landing) and the flying sub continues down to the ocean floor (no fail "safe").

You know there is no provision for recovering a military sub via floatation in the case of a hull leak. I suspect it would be physically impossible. But do you know how to scuba dive? Way back in the day when I first certified we practiced going to 60 to 100', removing the gear, and swimming to the surface. This requires some training, a calm head, and probably some luck, but many people have done this to reach the surface. The danger is that if you hold your breath while rising from that depth to the surface you will burst your lungs like a balloon, drowning in your own blood. One thing they teach you is that from depths below that it is sometimes hard to tell where the surface is due to the lack of light to give direction - which way to go! Submariners are trained in a 100' tank to be qualified on the boat (except for me since I was a reactor operator and they didn't want to spend any more money on me). I believe the current certification has been drastically cut/shortened so that you have to take additional certification courses (mo money) to get this type of training.

Marc

 

Hi Marc.actually thats not entirely correct- since the hull itself is submerged so the ratio of the submerged object to the one piercing the water is about 80:1 or something therebouts. hence it goes beyond the hydrofoil effect, and starts acting as a bulbous bow. the sail splits the water creating little drag... again see the bulbous bow of a ship--the reason its used is to take advantage of that effect. it actually increases fuel conservation. and betters the hydrondynamcs...however just to clarify--i would run about 20 ft below the surface on most days with only the snorkels on the surface--but two snorkels- this actually creates more drag than the sail would-...but at a leisurely speed of like 6 knots--its effect will be minimal or it should be--guess we will find out...
i will address the others posts later today...

 

"Such a device could be a death trap."

That's one of the largest understatements I've ever seen.

This guy is one out of 7 billion, he's a nut bar and very dangerous to himself. He may or may not realize that but it really doesn't matter, he's going to do what he's going to do and likely die trying. He may come to his senses or all the criticism here may only motivate him to an earlier demise. He wont do an unmanned crush depth test, it's too expensive and too destructive.

Can you even imagine what it would be like to implode at 100 feet? That's 3 atmospheres. 70 feet LOA is about 1200 square feet of surface area exposed to the water outside. About 6000 pounds per square foot is about 7 million pounds of pressure squeezing the entire hull, roughly 3600 imperial tons. (It's actually more but I calculated for the one atmosphere "pressure" inside.) And if he makes it to his 200 foot target depth, it'll be double.

At least it'll be quick...

You will be alone right Tug?

-Tom

 

One thing worth looking at to avert some of the significant buoyancy and depth control problems is to get rid of the need for compressible buoyancy if you can. Small, deep-diving, submersibles avoid using compressible buoyancy systems completely, by using things like flexible pumped oil tanks. Pumped oil buoyancy control works by using flexible bag tanks inside the ballast tanks. These are fed from oil tanks within the pressure hull and are incompressible. This means they are relatively unaffected by depth change, making the linkage between plane trim control and buoyancy compensation easier.

The big downside is the significant reduction in ultimate buoyancy that can be achieved by the use of oil instead of air, but given the simplification of control it gives it may be worth considering.

 

As someone with some time in submarines on trials work, I'd say you really need to balance some of those points and look at them a bit more closely.

The risks are considerable, from unknown hull structural flaws causing hull rupture (even 200 ft is over 6 bar), through the issues associated with scrubbing unwanted gasses from the internal atmosphere in a controlled way, through to the very considerable technical challenges in making hatches and ports secure and leak proof without introducing stress raisers in the pressure hull. There are good reasons for boats having cylindrical pressure hulls with a teardrop non-pressure hull casing around the outside - worth considering, as it's damned hard to make a tear drop shape with good and known structural integrity, even for operation at just a couple of hundred feet.

Some of the pluses up in that list aren't quite right, either. Subs give a pretty nasty ride unless they are running below the wave affected zone (which means being around 20 m or so down, more if it's really rough). They have limited reserve buoyancy (in the UK we design for being able to surface with one flooded compartment, the old Soviet boats didn't even have this much reserve, hence, in part, their high serious accident rate).

Navigation is challenging. The INS required needs to be very sophisticated to give you a reliable nav system when you can't access GPS, LORAN or whatever because your submerged. Dead reckoning is very difficult, because sub-surface currents are rarely known or marked accurately on charts and they vary wildly from surface currents (they will often be in the opposite direction even).

Attitude control is far harder than it seems and is critical for operation close to shore, even on a 50ft boat. It's quite possible to have the bow or stern hit the bottom from vigorous trim changes, for example, and a sub has a high polar moment so once swinging wants to carry on.

Also it's possible to get a submarine out of pitch trim to the point where it cannot recover back to the surface from an over vigorous nose-down plane angle. What happens is that the rate of descent can result in a pressure increase that the tank blowing system cannot keep up with - meaning you keep on going down unless you have enough plane authority to pitch back up - the planes then become highly safety critical.

As for "seeing more underwater" I guess you've never been at depth and tried it! Suffice to say that down below a few tens of metres the vis is crap as a general rule. Around this part of the world, even in shallow water, the vis rarely exceeds a few metres.
I should add a qualifier - I absolutely hated being in a submarine, so much so I once paid my own air fare home rather than go back to the UK on the boat. It colours my views a bit...........[/QUOTE]

Hi Jeremy, I appreciate your noteworthy posts

with a small 1 atm sub you dont need scrubbers..this eliminates complexity.The sub has enough air for about 12 hours or longer without the need for any re-exhaustion. diving to 200 ft will not be done on a regular basis -most likely my dives will be in the area of a couple of atmospheres and if i dive it will be avoid a berg or what have you. then resurface again- which is why i really hated to put to rest the idea of a type XXI replica. the surface running characteristics were better-however having said that--its still a better ride submerged in swells than a boat on the surface in 25 ft seas anyday. ive been out in 25 ft swells and i know that there are more than a few boats built from this site that wouldn't handle that type of stress...which lets me say that we are really dealing with the different issues- no less or more thought or technical skill goes into a sub than a boat--just different mathematics and theory. when it comes to hatches--ive seen many hatches on civil subs--they really arent all that problematic. a good seal and a good linkage to the hull is whats required--remember that the pressure of the water will tend to seal up leaks under pressure. the tearddrop--well i would have to respectfully disagree--this is the most advantageous design for a pressure hull other than a spherical hull. in fact the actual pressure hull on my vessel is round and cyclindrical -note the extent of the hull in the sub- the rest is free flooding and ballasted. see the pic- yes reserve bouyancy or little of it--is a given- as for navigation- yes this does represent some problems- i have been working on solutions to that but generally -you must navigate the same way as a surface vessel.--know your charts .depths use a gps..etc..once you know the area then you dive--there are rules and procedures for safety in a dive to set up...
emergency dives are rare. a typical depth finder is indispensible...
the polar moment you mentioned- is much more pronounced and problematic on a large sub- almost negligable on one 52 ft long and 7.5 dia.
for operational subs of this size- see youtube under UC3 Nautilus...this is an example of a good sized-(larger than mine) civil sub which has not encountered the difficulties you mentioned- to my knowedge... as for the ballast system--having onboard compressors -and the dangers inherent in them-not tomention the costs and energy needed to run one with enough power to charge tanks for a ballast blow- makes using high pressure low volume pumps for a static dive more safe. for a quick dive --you simply dont use the static system and rely only on a dynamic dive.if you corkscrew-then you just stop and float back to the surface.

if you have the time and know the area- thats where a static dive is fine-- in which case a pressure washer pump with 1600 psi capablity will pump out the few litres needed to static dive and control the trim below. don't worry--i have thought of all the things you mentioned and then some -for instance if done in steel--you will need a pressure bleed off valve in the event of rapid ambient temp changes- this is much less problematic with a concrete or polymer hull as the condensation will be 1/6th less than that of steel. also, steel buckles much more rapidly than concrete . concrete is a far more stable material to slow down buckling effects. an external pressure vessel will be subject to different stresses than an internal one-
in my part of the world-the water quality is about 50 ft clear-almost carribean quality visability on the great lakes... and i plan to run in the carribean -almost never in cloudy water.
as for travel in one--its not for everyone--and the viewports are the only way to make it really yacht like...the camera system i will use will of course allow for some comfort but i would never want to be in a military sub at all..so i can unserstand your thinking on that -i would have flown home too!!