SSS- Simple Submarine Systems

Trim Ballast

Once we have an effective fast response 3D control system we need to address the long term "trim". Like an aircraft sub control systems are designed as inner an outer control loops. The slower loops are inside the faster loops and are designed to adapt to long term >10 second changes in trim conditions.

So the autopilots gyros and control surfaces respond instantly to forces that destabalize the sub while the slower loop trys to minimize the average deflection of the faster loops control surfaces to minimize drag.

In a sub that means "trim tanks". Primarily fore/aft. these help make up for people moving arround and changes in the CG as water density changes with temp and salinity.

Again we can use off the shelf civilian 3D autopilots with automatic trim compensation to power a pump that moves water fore or aft over a period on min.

 

Two great posts Tom!

I agree about the top 30'!

For us divers I plan to have scuba on board but as a Volunteer SAR I can tell you the coolest characters can break down in an emergency.

Simplicity always seems to trump complexity and of course the simpelest rescue is the one that never happens due to good planning!

I have even thought of turning the exit hatch tube into a small 1 ATM rescue craft capable of holding 8 people and the solas life raft.

In an emergency it could be edjected out of the top or bottom hatches and acts as a kind of dive hatch the rest of the time.

If that did not work you proceed to individual free rescue. And that means training (scaring) everyone who sets foot onboard!

Be Wise, Be Safe

 

I have helped design a few drift gliders and i can tell you that limiting the dive depth to 120' is a big problem. It takes more "time" than that to build up the speed needed to gain 3D control due to the power required for aceleration. It is also very difficult to do with any significant internal air volume. You need huge oil pistons or ballast tanks.

That said I hav seen several designs for 1200-3600' max depth habitable gliders that make 6kts on a few hundred watts. Even 8 kts under 1KW. There is a surprisingly large amount of power available whena 200T sub drops 1' for an hour!

275Ton * 2000lb/ton = 550,000lb, 550ft lb/sec= 1hp
550,000/550 = 1000 / 60sec/min = 9HP (for a 1' per min dive profile)

1FPM = 9HP (6.75KW) (60' = 6 KW for 60 min = >6KWh) (12kts + 400W power)
2FPM = 18HP (120' = > 12KW) (15kts + 3KW Power)
3FPM = 27HP (180' = >18KWh) (18kts ??? if your really GOOD)

remember there is no propulsion efficiency loss when using a glider!
A 200T sub can even use it's inertia to breach like a whale and exchange air. LOL


One possible solition for shallow dive gliders is to use thrusters for control and glide for propulsion so that you are not so dependant on speed for control.

Interestingly, they built gliders that recharged themselves via the prop while gliding to achive months of operation. Trade Speed for Power!
Now that's what I call "Green"!

ST, how much food are you planing to bring on your sub? LOL

I plan to bring A lot of food, and company! LOL

 

Food

How much food on my sub?

Only what's in my stomach. No room. Think of it as a sub you wear.

Displacement: ~650 pounds (~300kg).

Buoyancy: -2/+4 pounds (approx. -1/+2 kg) the usable weight of air in an

80 cubic foot scuba tank.

 

Hmmmm....

Sounds like a newt suit glider...
Those actually work out well due to the very limited internal air volume (lungs) after you fill them with a bag of water called a human.

Two models:
1) rubber (ambient)
2) metal (1ATM)

external thruster optional
LOL

 

All kidding Asside... This sounds cool...

All kidding Asside...
This sounds cool...

At ~300kg it sounds like something I might be able get through the hatch. If I make it large enough. You sound very practucal if you plan to use existing "tanks" for ballast control.

And your absolutly right, scuba gear with a scooter have all the same systems that any ambient sub has in it's simplest form.

On the scale of simple.

1) Mask
2) Mask & Snorkle
3) Mask, Snorkel, Fins
4) Hooka (no mask, no fins, no snorkle, no BC)
5) Mask, Snorkel, Fins, Spare Air (Tank & Regulator) (Human Glider, Inhale / Exhale for boyancy control)
6) Mask, Snorkel, Fins, (Tank, Regulator, Gauges, BC)
7) Mask, Snorkel, Fins, (Tank, Regulator, Gauges, BC), Scooter
8) Mask, Snorkel, Fins, (Tank, Regulator, Gauges, BC), Scooter Carying Air
9) Mask, Snorkel, Fins, (Tank, Regulator, Gauges), Scooter Carying (Air + Weights + BC + Wings = Scooter glider)
10) Same as 9 but you ride it.

After 10 you start move to 1 ATM.

a) Is yours wet or dry?, Ambient or 1ATM?

b) Are you aware that there is a guy that converts "small" inexpensive submersible troling motors into ROV motors good to > 200'.

c) Are you planing to run a re-breather? The new lithium hydroxide rolled cardboard types are very good and very simple. Not as cheap as poweder but langer lasting and safer.

d) Do you plan to use an inexpensive "pinger locator" to find your way back to the boat when it moves to pick you up at the end of a "long" drift dive? Or do you plan to surface, get a fix from a small gps and radio the boat.

e) If your sealed in like a newt suit whats your emergency exit strategy in the event of ballast failure?

 

Micro sub

PanAmMan,

It's a 20 inch (50cm) diameter, assymetric bulb with a 50 inch (1.25m) wing

span (big hatch!). About 11 feet (3.5m) long.

a) Dry. Delayed ambient, Range: +/- 1 ATM.
b) No
c) No re-breather, just a bottle and a reg.
d) No. Minimal electronics. Dead reckoning.
e) Ballast failure would mean flooding.
Exit strategy: 1) Beach or
2) Emergency exit, ascend, loose the sub.

If you want to personal message me your email, we can talk further.

Tom

 

Question about Propane tank nonSub- displacement

I have an extra 1000 gal. residential propane tank, I dont want a sub, I think they are too dangerous for alot of reasons, I always want fresh air thru the top. the wt. of the tank is 1800 lbs, but at 1000 gallons, thats 8300 lbs of buoyancy-minus 1800lbs for tank -that's 6500 lbs., will it float like a cork???? Well, it would be indestructible, in whatever conditions you could imagine... scince it will have a hull speed of a knot- it should be the Knot-a-sub!

dimensions are:
Quality Steel Propane Tanks
Size Diameter Length Height Weight
1000 Gal 41 " 192" 49" 1800#

I thought I could add outriggers for roll stability, but could someone tell me where the waterline would be? possible hull speed?

 

Not - a - Sub

Skipper Walker,

I think you hit the nail on the head, this is "not-a-sub.

Even new propane tanks do not make for viable subs.

Unless you're willing to x-ray every square inch of it,

twice. Then, pressure test it to five times it's service

depth by ballasting and lowering it down into the murky

depths. My biggest question is why do you ask?

As a mariner you know water line depends on loading.

I take it you're curious where the line would be unloaded.

Why would you put outriggers on it. Hull speed submerged

or unloaded with outriggers? If so, how heavy are the outriggers?


I'm going to guess about 14 or 15 inches from the bottom when

on it's side, valves up (which of course they wouldn't be in reality).

But, you're a mariner, you can sit down and figure this out. No?

How far off am I?

Then, figure out the pressures at depth compared to the service

pressure rating on the tank and you'll suddenly realize, the thing

can't go very deep!

Hull speed: Guessing..................3 knots.

One more question: why do you have an "extra" propane tank?

Tom

 

Iron Bobber

Well- the whole point is, I have this tank, I think it would be a novelty, not a serious boat or submarine, something in between, like the cement sub seen in other places in this forum, it really isnt made for diving, it is made to be stable and be moved with about 2 hp. and its FREE!
I cant think of another more indestructable 'apocalypse' boat for one person as well! So- outriggers will keep it from rolling over and taking on water, loading would be the ordinary 250 lbs of gear, again, this boat will NEVER be more than 50% under the surface..... Bulkhead in the aft hemisphere with a small sealed off engine with good ventilation, and a bearing and seal thru for prop.
And finally, my parents gave me my name, musta been funny.... but thats just my name not my title. sorry for the confusion, but I couldnt be more landlocked. looking for a way out now.

 

Okay...

This is starting to make some sense now.

FREE, like a white elephant? Not to you I suppose.

So, through some math, you can calculate where it will sit in the water. 62.5 pounds per cubic foot for fresh water and 64 for salt, you choose.

However much weight you have is how much weight (therefore volume) of water you will "displace".

Or, you can just put it in the water and see...

If you load it correctly, you wont need outriggers.

Personally, I think you're nuts, but what do I know.

All the power to you. Have you considered cutting it lengthwise in half,

welding the halves closed and building a party barge on top catamaran style?

Or SWATH would be another option. Google it, you'll see.

If you come up with any designs you think feasible, post them and you'll get lots of feedback.

Good luck and have fun, don't hurt yourself.

Tom

 

You have seriously misrepresented PSUBS.ORG and are also promoting much more complex design than necessary. PSUBS has over 12 years of email discussions archive on the website covering all kinds of topics including reasons why most of the ideas you are presenting here are illegitimate.

KISS in terms of collision avoidance means don't dive in heavy traffic areas, and if you do, have a surface boat with you displaying a dive flag so that other vessels stay clear.

If you aren't fabricating according to ABS or ASME standards, then you are experimenting in an area that is extremely unforgiving. Neither ABS or ASME will certify a concrete sub. Read about Seaker100 on PSUBS.ORG to find out what can happen with a failure at only 30 feet.

Don't reinvent the wheel.

 

Interesting Thread, but what is the mission for this Submersible?

Hello PanAmMan

Not sure what is the mission for this Submersible

I am wondering about the following:

• Where - Coastal, Reefs, and Atolls (Not Deep Ocean)
• Accommodations - More than one person (How Many More?)
• Transportation to Dive Site (Self or Support Craft)?
• Dive Conditions - Sea State?
• Use - Recreational or Commercial?
• Duration - How long of Dive?

Found this link which maybe help to you http://www.underwater.pg.gda.pl/00_public.htm

Check out the one for Submersible Propulsion and Energy has following:
"The base for systematic approach is a submersible system break down that was adopted following careful analysis. Considering list in Table 1. it is difficult to completely separate matters of propulsion (or rather motion control) and source of energy, from other subsystems of hypothetical submersible. These are usually cross-interlinked on different levels. For this reason it is understood that one must be aware of these correlations while considering various designs that we adopted in our systems. This allow us to concentrate on very specific matters.
Table 1. Submersible subsystems break down
Group 1. Work systems and instrumentation
1.1. Observation equipment
1.2. Manipulators
1.3. Hydroacoustic space Visualization equipment
1.4. Oceanographic instrumentation
1.5. Communication equipment
1.6. Navigation equipment
1.7. Emergency equipment
Group 2. Diving and personnel transportation
2.1. Divers and transferred personnel
2.2. Tools
2.3. Diver life support
2.4. Diving chambers
2.5. Mating skirts
Group 3. Control system and crew
3.1. Control system
3.2. Crew
3.4. Control panels
3.5. Isobaric compartments life support system
3.6. Pressure vessels for crew and controls
Group 4. Motion control
4.1. Surface buoyancy
4.2. Variable ballast
4.3. Trim
4.4. Propulsors
4.5. Hydroplanes
4.6. Anchors
Group 5. Energy supply
5.2. Main primary sources of energy (Heat engines, fuel cells, nuclear sources)
5.1. Main secondary sources of energy (accumulator batteries)
5.3. Umbilical
5.4. Emergency sources of energy
5.5. Power distribution and energy transformers
Group 6. Externals
6.1. Frame
6.2. Fairing
6.3. Bumpers
6.4. Floats
6.5. Ballast"

My recommendation to keep it as low cost as possible is to do the following first:
DETERMINE WHAT YOU WANT AND WHY YOU WANT IT
MISSION(s) STATEMENT
MISSION(s) PROFILE(s)
MISSION(s) CAPABILITIES REQUIREMENTS

 

Not exactly a SSS but I toured the HMCS VICTORIA (SSK 876) today in dry-

dock. She is nearing the end of a five year refit after purchase from the

UK. Formerly, the HMS UNSEEN (S41) a Upholder class, 2400 Ton, 70 m

submarine she was sold to Canada in the late 90's along with three other

sister ships in a controversial deal made by politicians. I was able to view

the screw as well. Sorry, no photos...

Tom

 

that's not gonna to work!

in case of a collision you will most probably have your 'cracks' on the topside of the hull making water dripple or flood in at these places and any air you are adding from a compresed air-tank is going to stream out those leaks immidately... you will make a lot of bubbles but you will not be able to 'keep' or 'maintain' any air inside the hull...

if the hull is broken on the topsides or at least above the 50% hull-line you are always referring to - simply adding air will not keep the water out...
water is denser than air and where water is coming in... air is escaping a lot faster!
it IS an option if the damage is BELOW the 50% hull-line - so you have an sealed of and airtrapping bubble above - adding compressed air will even push any already incomed water as far down as where the cracks are...

but in general i think that if the hull of a submarine is breached you have 2 options:
- seal it of IMMIDATELY or
- leave the craft ASAP