Holes in the pressure hull

[Deathblow]

I'm trying to figure out all the holes that a submarine has that have to penetrate the pressure hull. Don't ask me why, I just have to know because I'm an obessive-compulsive type ok? I just need to know!

So far I've got (staring from front to back)

1. Torpedo tubes
2. Cable relay from the bow sonar array
3. Forward weapons loading hatch
4. Forward escape hatch
5. Sail access hatch
6. Trim tanks/ballast tank ports
7. XBT launcher
8. Seawater coolant flow hatch? in a SSN that is.
9. Inlet for the seawater to freshwater conversion tanks
10. Aft escape hatch
11. Countermeasure launcher
12 Main drive shaft
13. Maybe a waste disposal hatch? To dump sewage?

Anything I'm missing?

EDIT: Stuff I forgot.

14. Sail penetrating mast like the scope, exhaust, snorkle, hole, etc.
15. Auxillary seawater intake
16. Hydraulics for control surfacts (I didn't realize these were originating inside the pressure hull.
17. Other stuff that I don't even know what they do.

[TLAM Strike]

The masts and Scope.

[Deathblow]

Oh yeah!! Forgot about those.

Except for the new VA with non-penetrating mast :|\

edited list.

[Bill Nichols]

Originally Posted by TLAM Strike

The masts and Scope.

Not all masts penetrate the pressure hull.

Trash Disposal Unit (TDU).

Seawater cooling for the Emergency Diesel.

Don't forget the diesel exhaust and main air induction (i.e., snorkel).

[Bubblehead Nuke]

Lets see.. on a 688 flight II

Forward:
Torpedo tubes (X4)
Torpedo ejection pump door (x2, one for each bank)
Weapon Shipping hatch
Periscopes (x2)
Bridge Access Hatch
Various VLS hydraulic lines
Sanitation overboard fittings (x2 - one above and one below the waterline)
Floating wire antenna
Forward Escape trunk
Snorkel induction Mast (doubles as ventilation shaft)
Diesel Exhaust
Diesel seawater inlet and outlet
Hydrogen overboard dump
Trash Disposal Unit
3" countermeasure tubes (x2)

Aft:
Steam Generator Blowdown (x2)
Main Seawater Inlet (x2) & Outlet(x2)
Aux seawater inlet and outlet
PCST overboard
Stern planes & rudder hydraulic ram
Shaft
After escape trunk

[Bill Nichols]

Originally Posted by Bubblehead Nuke

Lets see.. on a 688 flight II

Forward:
Torpedo tubes (X4)
Torpedo ejection pump door (x2, one for each bank)
Weapon Shipping hatch
Periscopes (x2)
Bridge Access Hatch
Various VLS hydraulic lines
Sanitation overboard fittings (x2 - one above and one below the waterline)
Floating wire antenna
Forward Escape trunk
Snorkel induction Mast (doubles as ventilation shaft)
Diesel Exhaust
Diesel seawater inlet and outlet
Hydrogen overboard dump
Trash Disposal Unit
3" countermeasure tubes (x2)

Aft:
Steam Generator Blowdown (x2)
Main Seawater Inlet (x2) & Outlet(x2)
Aux seawater inlet and outlet
PCST overboard
Stern planes & rudder hydraulic ram
Shaft
After escape trunk

What he said!

[Henson]

Lets not forget depth sensors.

The answer to your question is more than you could possibly expect.

All hatches and trunks, hull & backup valve sets, weapon/CM tubes and associated equalizing valves, etc.

Why do you want to know? Is there a project you're working on or are you just interested?

[TLAM Strike]

Originally Posted by Bill Nichols

Not all masts penetrate the pressure hull.

That’s why I left it ambiguous.

At least the cables from each mast penetrate the pressure hull.

[Kapitan]

Dont forget the russian version of a quick shower !

[Deathblow]

Originally Posted by Bubblehead Nuke

Lets see.. on a 688 flight II

Forward:
Torpedo tubes (X4)
Torpedo ejection pump door (x2, one for each bank)
Weapon Shipping hatch
Periscopes (x2)
Bridge Access Hatch
Various VLS hydraulic lines
Sanitation overboard fittings (x2 - one above and one below the waterline)
Floating wire antenna
Forward Escape trunk
Snorkel induction Mast (doubles as ventilation shaft)
Diesel Exhaust
Diesel seawater inlet and outlet
Hydrogen overboard dump
Trash Disposal Unit
3" countermeasure tubes (x2)

Aft:
Steam Generator Blowdown (x2)
Main Seawater Inlet (x2) & Outlet(x2)
Aux seawater inlet and outlet
PCST overboard
Stern planes & rudder hydraulic ram
Shaft
After escape trunk

Hey I did pretty good for a civilian.

*Making some edits*

btw what's the "Steam Generator Blowdown" and the PCST overboard? Oh and a "Hydrogen overboard dump"? Sounds like something outta StarTrek.

[TLAM Strike]

Originally Posted by Deathblow

btw what's the "Steam Generator Blowdown" and the PCST overboard? Oh and a "Hydrogen overboard dump"? Sounds like something outta StarTrek.

If it was from Star Trek it would be a Deuterium overboard dump. The SGB I think ventilates the turbines and stuff, but I could be wrong.

[TopTorp '92]

I will be surprised if anyone can list all the penetrations. There are over 10,000 valves on a 688. Most submarine qualified persons will know those valves that are central to good damage control and they will know the valves central to their normal duties.

Excellent comments from Bill and Bubblehead Nuke above.

Vertical Launch System (VLS) on those 688s that have them:
*There is a pressure & vent control system that penetrates the hull. Major system components are inside the people tank. The system uses 700lbs air.

*In addtion to the torpedo tubes and other components mentioned by Bubblehead Nuke (a former shipmate of mine) the torpedo system uses equalization valves that must penetrate the hull. (Don't forget that the torpedo ejection system uses 2000 lb air.)

Other ship systems using valves that penetrate the hull:
*The sanitary system can either blow or pump to sea through PL-49 (I think I have the correct valve number.)
*The trim system has a blow and flood system to hover. I only used it for training and I used the flood part of the system for a couple of emergency deep executions. There are 4 Aux tanks on a 688. The blow & flood system uses Aux 1 & 2. The remaining portions of the trim system are excluded because they are not normally pressurized to sea. 700lb air is used to pressurize the tank and blow water to sea.
*The trim & drain systems each have hull valves in order to pump to sea. So, that is an additional two valves. I suppose that back-up valves should count as well. Make that an additional 4 valves. If I recall correctly, the flood & blow system anly ties a portion of the trim system. So, it is possible to uses Aux 1 & 2 for flood and blow operations while using the trim pump to pump water from tank to tank or from tank to sea. The reason I bring this up is because during a flooding casualty or any other casualty requiring rapid dewatering of the ship, the trim system can be used to generate some extra buoyancy. Also, the drain system can be cross-connected to dewater trim tanks and vice-versa.
*Emergency Main Ballast Tank Blow System (EMBT.) This system has hull valves actuated from the BCP. The back-up hull valves are always open. The hull valves are normally shut.
*The ship's whistle uses 150lb air in order to function. These hull & back-up valves are manually operated.
*Ship depth guages use hull & back-up valves actuated from the crews mess. 2 valves: hull & back-up.
*The hydraulics for the ships anchor penetrates the hull.

Do mechanical system penetrations count? There are too many for me to remember.
*MBT vent valve linkages penetrate the hull. These valves are hydraulically operated but the hydraulics remain inboard. However, the linkages penetrate the hull. There is also an indicator for each valve: open or shut.
*Mechanical indicators for a variety of hull penetrations themselves penetrate the hull.
*The TDU ball valve has a mechanical indicator.
*Torpedo muzzle doors each have a mechanical indicator.
*Torpedo ejection pump doors have mechanical indicators.
*The torpedo system has an equalization valve. However, I have no recollection whether it had a mechanical indicator.
*Rudder & stern planes use mechanical linkages for normal operations that penetrate the hull. I have since forgotten whether the bow planes or fair water planes use emergency back-up systems that rely on any form of a mechanical linkage back up. But if they do, then these linkages also penetrate the hull.
*Don't forget each 3'' launcher muzzle door has mechanical indicators.
*Many more . . .

Top Torp

[Deathblow]

Nice that's some good info. Not a description that going to be found in any library book. Thanks. No wonder the the max depth of a sub is so much shallower than the actual projected steel strength, with all those valves the probability of failure is compounded more and more.

[Bubblehead Nuke]

Originally Posted by TopTorp '92

I will be surprised if anyone can list all the penetrations. There are over 10,000 valves on a 688. Most submarine qualified persons will know those valves that are central to good damage control and they will know the valves central to their normal duties.

And just were are most of them?? Yep, aft

Excellent comments from Bill and Bubblehead Nuke above.

Why thank you.

Bubblehead Nuke (a former shipmate of mine)

shhhhh.. thats a secret! Oh well, cats out of the bag now

the torpedo system uses equalization valves that must penetrate the hull. (Don't forget that the torpedo ejection system uses 2000 lb air.)

The equalization system, if I remember correctly, was so that you could open the outer doors after flooding the tube. It was only exposed to sea pressure when the ejection pump door was open. There was not a seperate isolation for it.

As for the 2000# air used. Oh yeah, how could ANYONE forget venting the ram inboard after shooting a weapon. A 688 shooting a torp makes a VERY distictive noise transient as you pointed out to me YEARS ago.

*The trim system has a blow and flood system to hover. I only used it for training and I used the flood part of the system for a couple of emergency deep executions. There are 4 Aux tanks on a 688. The blow & flood system uses Aux 1 & 2. The remaining portions of the trim system are excluded because they are not normally pressurized to sea. 700lb air is used to pressurize the tank and blow water to sea.

Crud, I can't BELIEVE I forgot that one.

Add Trim and drain system to the list. One fore and one aft. Additionally to using this system to move ballast around a boat, you could open interior hull suctions and use the system to move water out of the largest tank on the boat, the ones that hold the people!

Also, I do not think our boat HAD a hover system on it. I know that the later 688i's had them because it is used to pop thru the ice.

So, that is an additional two valves. I suppose that back-up valves should count as well.

This is a VERY good point for you non-quals out there. EVERY hull penetration greater than 1" (I think that was the smallest pipe size) has a primary and then a secondary isolation valve.

*Emergency Main Ballast Tank Blow System (EMBT.) This system has hull valves actuated from the BCP. The back-up hull valves are always open. The hull valves are normally shut.

I think I need to requal!

*The ship's whistle uses 150lb air in order to function. These hull & back-up valves are manually operated.

Ok, that is an EASY one to forget.

*Ship depth guages use hull & back-up valves actuated from the crews mess. 2 valves: hull & back-up.
*The hydraulics for the ships anchor penetrates the hull.

Do mechanical system penetrations count? There are too many for me to remember.
*MBT vent valve linkages penetrate the hull. These valves are hydraulically operated but the hydraulics remain inboard. However, the linkages penetrate the hull. There is also an indicator for each valve: open or shut.
*Mechanical indicators for a variety of hull penetrations themselves penetrate the hull.
*The TDU ball valve has a mechanical indicator.
*Torpedo muzzle doors each have a mechanical indicator.
*Torpedo ejection pump doors have mechanical indicators.
*The torpedo system has an equalization valve. However, I have no recollection whether it had a mechanical indicator.
*Rudder & stern planes use mechanical linkages for normal operations that penetrate the hull. I have since forgotten whether the bow planes or fair water planes use emergency back-up systems that rely on any form of a mechanical linkage back up. But if they do, then these linkages also penetrate the hull.
*Don't forget each 3'' launcher muzzle door has mechanical indicators.
*Many more . . .

Top Torp

Ok, the mechanical indicators were easy. They were switches at each end of the bellcrank that operated the valve in question. In the even of electrical failure you can LOOK at the things and see what position they were in, they were not physally ON the valves themselves but on the hydraulic operators. It was presumed that the operating lever would not break. There was not an actually electrical penetration involved.

On the stern planes and the rudder, there are graduated scales that can tell you current rudder/plane position in the hydraulic ram. I don't know HOW many times during a JAM DIVE drill I had to take manual control of the stern planes and return them to neutral. I DO know I could take manual control without looking at the book, in about 15 seconds. It was 4 valves if I remember correcly. Climbing up to the things at a 30 degree down angle.. now that took a bit longer.

[Bubblehead Nuke]

Originally Posted by Deathblow

Nice that's some good info. Not a description that going to be found in any library book. Thanks. No wonder the the max depth of a sub is so much shallower than the actual projected steel strength, with all those valves the probability of failure is compounded more and more.

Each system exposed to seapressure is designed to handle it. It is not so much a lack of strength but how fast things can south when things go wrong.

You should see the flood trainer we go in. It starts out small, then they kill propulsion on you. As the ship gets deeper the leak rate increases and you sink faster building seapressure FASTER. Thus MORE water comes in. It does not take to long before the instructor says 'BANG' on the intercom.