SSS- Simple Submarine Systems

Mydauphin,

I am not building "yet".

I tend to build systems from the inside out.
Safety first, efficiency & simplicity second.

And of course a clear understanding of what a day in the life of a system and it's users is a must.

That said I do not see a way today to achieve my goals in a metal sub. I may never meet them with any hull type but my peers would chucle at that while they quietly place "their' bets on seeing that sub before anyone could imagine. Becaue they know I will find a way! Even if that includes maturing a technology like cemente hulls or inherantly safe boyancy control.

I posted some possible prices for a 'possible" cement sub based on SSS fit out. concrete-submarine-24361-16.html#post281104


In general I estimate 4 to 6 times the hull cost. But since i do not yet know the cost of the hull I do not yet know what it will cost and if that is a practical return on my investment. i do know that a metal hull achieving my golas will cost "Millions" by the time i achieve the volume i want with the 100% hull testing that I and my insurer will demand.

My posts have even included a basic outline of the "Proof" testing I feel is a requirement for a life critical manned system. I have no death wishes but I and you regularly depend on many of my designs on a regular basis. Needless to say were all still here. LOL

Of note is the fact that the cost of the metal and testing for a metal hull do "NOT" drop by limiting the hull to less than 150'. that inherantly seems like a "materials" problem setting the cost floor. which is why so many people familar with metal marine systems see the cemente hull cost projections with such 'sceptisism".

But re examining assumptions is where most incrimental inovation takes place.

 

Where should we have discussions about HULLs?

I am inclined to start a thread outside concrete submarine since the goal is to evaluate Steel vs cement vs ??? With the goal of identifing a technology for a large hull that has much better cost per volume than what I see available today.

Maybee we should call the discussion by it's goal. "Sub Cruiser Hull"

I feel the discussion should include costs associated with 100% sonic or radiologic inspection of seams and or the skin as well as ongoing maintenance concerns like corrosion / ablasion / depth cycling / vibration / marine growth control and or maintenance.

I am open to sugestions on where this discussion should take place.

The systems used inside this and other < 150' subs would stay here since most are probably independant of hull type.

In the mean time I am still waiting for the flood of constructive sugestions about safety and other systems on this thread!

 

Mydauphin

how would you relate the FIT out complexity of a >70 ton surface vessil with a 200T (<120' operating depth) sub providing a small fraction of the occupancy volume?

 

Mydauphin,

My regular sailboat "if you could call it that" uses composting toilets. You have to remove a "Bucket Size" tray once a month and the material is dry. with a carbon air filter they are even certified for use in mines!

The larger problem is of course your sink and shower "grey water". That discussion would make a neat cross post to Simple Sub Systems.

 

Please Note

PanAmMan,

You make several good points and stimulate the discussion.

I appreciate your enthusiasm.

I did note, out of 19 posts thus far on your new thread, 13 are yours.

A couple of clarifications: water is non-compressable, so it's density does

not change at depth unless by temperature and/or salinity.

Perhaps you meant pressure.

The bends does not occur from simply ascending from depths below

120 feet (~40 meters) alone. The bends occurs when nitrogen levels in the

body increase, over time, at depths below 30' (~10 m) and are not allowed

to release slowly while ascending. One is risking an air embolism however,

during rapid, or emergency, ascent from any depth.

Cheers, Tom

 

Cost of building a boat vs sub

Here is my cost to rebuild a boat by size. Which means get a boat working from the hull up, nothing fancy, just running with some used equipment mixed in.

20' $5000 engine, steering, fuel, electrical
27' $10,000
33 $15,000 Can be higher with HP engines
38 $20,000 Inboards
45 $35,000 Diesel, shafts, rudder
55 $70,000 Wider boat, more systems
65 $120,000
70 $250,000

cost of Hull used is about $1000 a foot

I am using these numbers for you to figure a budget for a SS sub.
My guess that foot by foot a sub would be a lot more money. Some have said that less because horsepower requirements are less, but safety and things like electrical are going to have more carefully chosen. Many components are going to have be custom made... more cost...

 

1) Yes I am trying to jump start things with a few provocative seeds.

2) Yes I actually meant that the air entrapped in the sub would change density and volume and therefore impact boyancy. In a hollow steel sub which 'IS" compressable the same will happen changing boyancy as you dive. In a flooding emergency these can be fatal.

3) Your absolutly correct! It is actually the nitrogen (Bends) and assent rate (Embolisms) you must worry about hence my desire to minimize the "Time at preasure" before you self rescue by not using a lockout trunk that must be cycled. Modern self rescue hoods are designed to optimize assent rates to minimize the potential from embolisms during asent. My built in recording reminding a non diver to breath and not hold their breath should help a lot as well.

4) If we use my proposed preasurized make up air system to compensate for compression of the 1 ATM in the sub to a much smaller volume due to high preasure flooding in a major breach, at 120', then we want the people out ASAP to prevent nitrogen buildup at greater that 1 ATM.

Thanks for the great post!

 

Great Numbers, Thanks!

I agree with that! Safety and rescue systems on a sub, even when simple, are stil more complex and costly than on the surface.

So at the low low end a $500K sub that is 50' comes in at arround $10K/ft. And that is on a sub that NEVER goes below 120' with people on board!

This of couse is assuming that the claims of a $100K hull are realizable and a rule of 5X hull cost for fit out in a Super Simple Sub is the focus and not a luxury yacht.


What do you think?

 

I build concrete seawalls for a living. My cost for building your 200 ton sub, not including location and crane to put boat in water is around $32000 based on concrete costs.
Everything speaks of 200 tons, that is weight of concrete not size of boat. I don't know if 200 tons would give you a 50 foot sub etc. I would look at that later.

200 tons of concrete is about 7 trucks, Or about $8000
Concrete $8000
Pumping cost $1000
Molds $7,000
Rebar $5,000
labor $10,000

So that is about $32,000 my cost. I would sell such a project at around $50,000.


This also does not include hatches, portholes, engines, engineering....or any thing else just concrete hull. This is a guess not having seem plans, just that I build in concrete all the time. The average concrete seawall with king/batter piles and concrete tie beam is running about $700-800 a foot. Of course this has nothing to do with a submarine except that concrete itself is not that expensive, labor and molds can be more.

Also we haven't spoken about the many different concrete available, of methods to construct. Everyone thinks that building this in a third world country might be cheaper, perhaps but the advantage of personnel, equipment and quality of concrete may make building in US a better choice.

 

I tend to agree with your statement about US Build and quality control.

Much of the cost of "New" designes is in the engineering and materials slection. The largest cost differences off shore come in when you make the molds not the actual production.

Some consideration for the hull for unparralelled strength are spin casting, prestress reinforcment and the special high flow concreets (to avoide voids) that you have mentioned before. These tenique have shown extrordinanry resiliance to salt water, stress cycling (pounding and wave action), and > 30 year longevity in marine applications.

I guess I would feel safest starting with their formula, which I understand is very simular to those used for the platform legs but with the requirement to withstand being "pounded" into the seabed.

Anything that can withstand being pounded into the seabed, vibrated by 18 wheelers for > 20 yrs and hit by no less than 4 huricane must have a "little" safety margin designed in. LOL

It's interesting that the same guys have also identified plastic coatings that eliminate the threat of colinization by sealife. Another of the core issue to a sub that stays in the water 24/7/365.

You are also correct in assuming that the portholes and hatches are going to make up a significant part of the finished cost. these are typically the weak link in a sub so they will need to be overdesigned to match the safety margins of a concrete preasure hull. my back O napkin estimate is that they will cost 1 to 1.5 times the hull if you want any light inside!

 

Thanks

PanAmMan,

Thanks for clarifying.

I miss-understood your earlier posts.

Carry-on.

 

I could have been a lot clearer!

Tom you sound like you have a lot of experiance with "dive" related "issues".

Any sugestions of other ways we could minimize bend and embolisim risk during a self rescue?

 

Propulsion

Propulsion and control systems on submaries run a wide gammit from albacore like subs with a single very large slow turning screw for stealth to twin propeller systems that take advantage of traditional throtle steering.

In general modern sumbarine control is one of the most difficult due to a need to coordinate many types of control, main motor, 3D thrusters, rudders, elevators, dive planes and ballast.

Like a ship the most dificult thing to do is stay in the same place, second is slow maouvering and easiest are transit speeds. add to this the substantial added complexity of 3 dimensional manouvering and you quick see that expense and complexity grow quickly in the same way a piper cub is much simpler than a V22 osprey.

If you also decide that you want to minimize or eliminate moving through hulls to simplify maintenance of the preasure hull then you have to look away from many traditional marine technologies which rely on surface rated through hulls. Electricity and hydraulic motors are then your primary comercialized options.

Hydrualic motors are well suited for Intermitent Bow & Vertical Thrusters as well as Rudders and Elevators. They provide simple and reliable "exposed" operation to > 100M as well as significantly simplified fixed through hull connections. But they will cost you dearly (20-50%) in efficiency so they are not very good candidates for high eficiency main propulsion in a cruiser.

A high efficiency and high cost/hp "exposed" alternative to moving through hulls is the electric motor. The primary drawbacks here are cost and maintenance at sea.

A common alternative is the high preasure through hull. Like a normal through hull it has an OIL over AIR packing. To improve it's performance at depth the fitting is preasureized with air from a tank to always be higher than the outside preasure. their advanatages are low cost, high eficiency and an ability to work on the propulsion system w/o getting wet.

A third concept, and my personal favorite, is a hybrid control and propulsion system using a through hull to comunicate the HP and a 270 deg swiveling AZIPOD (like a sail drive). The props are swiveled by "exposed" hydraulic motors but the HP comes from the main engine(s). The wing surface of each azipod can acts as a control surface even if the motor is not running.

If you use two or even three of these attached to engines like the Steyr hybrid you get an extreemly efficient diesel electric sub with full 3D manouverability at any speed and tripple redundancy. And you could always steal parts off of one to fix the other two and still operate on the snorkel.

Optimally you would configure the three azipod in a triangle with one leg of the triangle vertical to act as a rudder and place all three out of harms way during a bottoming. A triangular grouped control surface provides precise 3D control at any speed and lets you fly your sub very stabaly using off the shelf private aircraft auto pilots.

The Steyr Hybrid system has a world class efficiency of >20Kwh/gal (Diesel) and comes in a hybrid package capable of 20KW (26HP) on pure batteries. An efficent submerged hull should be able to achieve 12kts on about 6KW (40MPG) and 18kts on 18KW. Max snorkel speed with all three engines running would probably be under 30 kts depending on how "clean" your hull is.


Try that in a 70 ton suface craft!

Most small < 60' yacht do not average over 18 kts and the best of them using air cavity hulls barely get 2MPG! And that MPG drops fast in any kind of seas.



http://www.steyr-motors.com/products/pdf/hybrid.pdf
steyr-motors.com/products/products.htm

 

Self Rescue

Well, that is a big topic with MANY variables.

The best I can do is give you my point of view or opinion.

I'll approach your question in a brainstorming manner by throwing out

ideas as they come to me. They may not be reasonable or feasible, but

this is the nature of brainstorming, one idea leads to another, hopefully

better, idea. They will be easily critisized by those who wish to.

Where am I coming from? I am a PADI instructor who spent five years

with the Canadian Coast Guard in Search and Rescue. I hold a Transport

Canada commercial tow boat certificate and have lived and worked on the

water most of my life. I am designing to build a micro submersible that is

so unconventional it defies belief. It's sole purpose is to have fun in the top

30 feet (10meters) of the ocean, safely.

If I were in a sub of the size discussed in this thread, I would want all my

SCUBA gear to don prior to exiting at depth in an emergency. This way

I could control my ascent rate and direction and be much better equipped to

await rescue on the surface. As this may not be reasonable, I would want

at least a deflated personal floatation device with a CO2 cylinder, my

perscription mask, and a "mini air" (12 minutes of air with a built in reg.)

It would be great to have a whole bunch of emergency gear released from

the sub to have on hand at the surface. All of it could be packed into a life

raft barrel. It shouldn't be overly buoyant so as not to blow away from you

on the surface and could even have some kind of drouge or sea anchour

attached. This would also slow it's ascent. I digress from your query. A

long buoyant line off the sub sure would be handy to control ones ascent.

Especially if it had air tanks with regulators on locking sliders. What may

be more appropriate would be a weighted line with a float at the surface

(like a life boat cannister). If the sub disappears "into the murky depths"

the equipped life-line would still be there. Perhaps the last one out could

release it from the sub. Don't overlook the fact that all the appropriate

safety gear is of little consequence if everyone doesn't know how and when

to use it. This is very important and should not be overlooked.

I think the best way to minimize bend and embolism risk would be to avoid

an emergency in the first place.

Thanks for asking PanAmMan,

Tom

 

Propulsion:

Single or contra-rotating is the way to go for efficiency.

Manoeuvrability should come from control surfaces.

Have you considered a glider approach? It's a pretty cool concept.

Autonomous research subs are using it as we speak (okay, type).

I don't have a web-site handy but check it out. It uses pitch variation to

glide forward both up and down. Now that's efficient.

I don't think drifting should be overlooked either.

It's a hugely successful scuba technique: drift diving.