[PSUBS-MAILIST] Ballon recovery was: Sub Safety

[MerlinSub@t-online.de (Carsten Standfuß)]

Nero Wolfe schrieb:
> 
> 
> if you want to be really unique, you could have the ballons deploy inside your balast tanks ;-)  it wouldnt' take THAT big of a gasbag to counter the weight of the hull full of water, so you could potentially keep it within 1-2' of the top of the hull.  given the boat you're building, you could do the same.  All you need to do is put the gasbag underneath the deck plating, and have it deploy like pontoons from there, if you do it right, say with two zodiac style tubes, you could even keep your hatch above water.  not by a lot, but enough that you could save the ship.  then too, you have the divers lockout.

Okay enginering is allways - some calculations : 

A. Calculation 

A.1.0 project name : CSSX Gas Ballon surface "parachute" recovery system 

A.1.1 start parameters: 

Sub sunken to the bottom at maximum operational deep, hull flooded, 
crew survifed this .., Ballast tanks allready 100 % blown out with air. 



A.2.0 variables : 

A.2.1	water inside the sub : about 50 m3 or t (65 cubic yards) 
A.2.2 	bottom deep          : 250 meter (820 feet) 



A.3.0 calculation : 

A.3.1 Size of bag : 

negative bouancy 50 t, positve force in tanks 10 t. 
boat should have a freeboard equal to the half normal freeboard equal 
to 5 t . 50 t - 10 t = 40 t + freebord 5 t = 45 t or m3 Gasballon 


A.3.2 size of the pressure bottles: 

45 m3 gas in a deep of 250 meter needs 
25 atms. x 45 m3 = equal to 1125 m3 gas at 1 atms. 
Storage pressure in the bottles: 220 bar 

1125 / 220 = 5,1 m3 Storage bottle space need to lift the boat from the
bottom
with a force equal to 5 t positve bouancy. 

Our biggest standard pressure air bottles have each 50 Liters (13
Galleons) each. 
5,1 m3 / 0,050 = 102 bottles. 



A.3.3 Weight of the system : 

Each bottle weights about 70 Kg (155 pound)
70 x 102 = 7,1 t (or 16000 pound) 

A.3.4 Cost of the bottles
Each bottles is about 200 Dollar 
200 x 102 = 20400 Dollar 

Maintance cost each year for the security test and stamp 
102 x 20 Dollar dived by 2 (all two years) = 1020 Dollar a year 

A.4 others: 

not calculate cost for the bags, weight of the air in the storage
bottles. 


A.5 Conclusion : 

On board bags for CSSX  = to heavy and to expensive . 
I will notice the position of the wreck and come back with two divers a 
surface ship and normal lifting bags and a standard 40 atms. compresssor

best regards - Carsten