Internal bulkheads and flooding

[marcelo_malara]

Recently we have briefly discussed the capsizing of the Barham in another thread.
David Brown wrote that longitudinal bulkheads in large machinery spaces should be avoided to diminish asymmetric flooding following torpedo damage, the simultaneous sinking of the three Aboukir cruisers in WWI being an example.
But then I looked for internal drawings in my books and found:

Hood:

4 BR: in line
3 ER: in line

Warspite before 1935:

4 BR: in line
3 ER: 1 row of 3

Warspite after 1935:

6 BR: 3 rows of 2
8 ER: 2 rows of 4

Scharnhorst:

3 BR: in line
3 ER: 1 row of 2 and 1 behind

Bismarck:

6 BR: 2 rows of 3
3 ER: 1 row of 2 and 1 behind

BR: bolier room
ER: engine room

So it seems that in WWI the longitudinal bulheads were avoided (at least in British ships). Between the war the tendency seems to revert to longitudinal compartments.

Was Barham modified in the same way that Warspite? If so, could this have been responsible of the rapid capsizing? Are longitudinals bulkheads really a liability?

[Tiornu]

It may be that Barham retained her original subdivision. She was scheduled for a thorough modernization after QE and Valiant, but obviously that didn't happen.
Battleships are much more capable of handling off-center flooding than smaller ships would be. Perhaps the clearest example is Dido. Several British cruiser classes had a pair of longtudinal bulkheads near the midships. This created "wing passages" that restricted inboard flooding but could easily allow extensive flooding along the ship's side. Dido was small even by cruiser standards, with a tendency toward top-heaviness. The result was a class with extreme vulnerability to torpedoes.

[marcelo_malara]

Battleships are much more capable of handling off-center flooding than smaller ships would be.

Thanks. That´s the key.

[Bgile]

The Iowas had alternating engine rooms and boiler rooms with no longitudinal bulkheads. Then the Montana class and Midway class carriers went to 3-across with very extensive subdivision.

I think the main thing is that one bulkhead down the centerline is probably counterproductive, but more than that is fine and even desired.

Of course this refers to the space inside the citadel. The side protective system tended to have as many as 5 bulkheads per side in US practice. I believe the final configuration involved the outer two compartments liquid filled to reduce list when hit there, and liquid slows shrapnel much better than water. The disadvantage is liquid transmits shock better than air, so you need additional void compartments between the liquid filled ones and the torpedo bulkhead of the citadel. These compartments were made of STS steel, which tends to flex without tearing. This system was arrived at after suffering many torpedo hits during the war, and was considered the best compromised. The fact is if you are hit by a full size torpedo which functions properly, you are going to suffer some serious damage and you just try to limit it's extent.

[Tiornu]

From memory, the NC class was not able to shift its liquid loading to the outer spaces because the designed piping did not make that practical. SoDak and Iowa made the switch. From the standpoint of shell protection, I prefer having the liquid layers up against the inner bulkhead where they are certain to intercept splinters before they reach the bulkhead.