2,000 tons of seawater in Bismarck's forecastle!

[José M. Rico]

Hi all,

If anyone is interested, I have recently modelled Bismarck's hull from frames 202.7 to 241.55 using a marine software and these are some of the results I obtained after running the hydrostatics report:

Draft - Hull Volume

9.3 m - 1,954.4 m3
9.6 m - 2,027.6 m3
10 m - 2,126.7 m3
10.2 m - 2,177 m3
10.55 m - 2,266 m3

Looks like a lot of volume there but those are the figures I got.

[Herr Nilsson]

The offical volume up to the lower edge of the tween deck is 2272 m3. So your results seem to be correct.

[José M. Rico]

Thanks for the confirmation Marc,
I was afraid the model I draw may have not been very accurate but it seems it is good enough.

Here are some more figures I obtained:

Draft - Hull Volume

7.9 m - 1,623.6 m3 (up to the armoured Upper Plattformdeck)
5.5 m - 1,083.9 m3 (up to the middle Plattformdeck)

[Herr Nilsson]

up to the armoured Upper Plattformdeck: 1667 m3
up to the middle Plattformdeck: 1007 m3

[José M. Rico]

I almost nailed it !

[Vic Dale]

The shell entered compartments XX and XXI, but what I don't fully understand is how the lower compartments came to be flooded. The ship was in action and should have been locked down to water tight integrity state one, and all doors and hatches should have been closed. We in the RN would have called that Damage Control State One. DC was one of the strong points in the German Navy and the RN learned a lot from their example during WWI and WWII. In the RN, opening a door or hatch without permission during a battle was severely punished.

I have seen the drawings presented by Mr Jurens, and with the holes above the armoured deck, I don't understand why there is no flooding indicated in the compartments where the shell entered.

As I understand it, the shell entered on the port side in compartment XXI, damaging the forward bulkhead, then exited through the ship's starboard side low down close to the armoured deck, causing damage to the after bulkhead. Both holes were above the water line, but below the bow wave and ingress of water was due to the bow wave forcing itself against the flair of the bow and into the ship. Flooding should have been contained to compartment XXI, but may well have found it's way into compartment, XX and XXII. It may be that the shell tore through fan trunkings and other structures in compartment XX, thus opening a route to the decks below.

The damage should have been more or less self draining as far as the holed compartment was concerned, since the exit hole was low down near the deck. I believe the real problem was the list to port induced by the hit adjacent to the forward boiler rooms in compartment XIV. If the ship was listing 9 degrees to port, the hole in the bow would not have been able to drain, so the compartments above the armoured deck will have held a considerable quantity of water, remaining permanently half filled and perhaps holding as much as 500 to 1000 tons.

My sources are the ship's drawing in the Baron's book and drawings by Koop/Schmolke.

[RNfanDan]

DC was one of the strong points in the German Navy...

Hi, Vic--
You may wish to locate and read the MOD report and assessment on Kriegsmarine damage control, which begins with the following excerpted passages (emphasis mine-Dan):

© Crown Copyright/MoD (1946).
DAMAGE CONTROL IN THE GERMAN NAVY.
The following article is compiled from the notes of an Engineer officer who recently visited the PRINZ EUGEN to report on methods of damage control and fire-fighting as practised in the German Navy. In the case of the German Navy one has always been led to believe that, in the intervening period between the two wars, much consideration had been given to the subject. This belief had been further strengthened by the severe punishment that such ships as the Graf Spee and Bismarck suffered, before being finally sent to the bottom. The visit to the Prinz Eugen was therefore looked forward to with considerable interest.
The visit, however, while revealing certain interesting features, brought to light the somewhat amazing
fact that, considered broadly, damage control and fire-fighting in the German Navy were much behind the times.

Hope this proves useful!

[Vic Dale]

Damage Control is a very broad and complex factor in the fighting efficiency of any warship and covers everything from sealing holes in the hull, fire fighting, alternative electrical circuitry and alternative piping routes for fuel and fire main around the ship, down to the materials used in it's construction.

When I was at sea, we had it dinned into us not to wear nylon and only to wear cotton in case fire melted the material, yet the modern fighting rig for men at the Falklands for example, seems to have included lightweight nylon clothing as standard issue. Even in my time they were starting to issue a nylon jacket, which went against all that we had been taught. The materials used for insulating the hull and trimming messdecks and passage ways accounted for a great many men suffering from toxic smoke inhalation and plastic insulation of wiring accounted for the rest. The old corticene decks had also been replaced with modern linos and they will have added further to the problem.

One of the biggest problems when a ship goes into action is fighting fires and many great ships were lost because copious amounts of water were pumped into the ship with scant regard for getting rid of it. I believe that this was the biggest single contributory factor in the loss of Ark Royal. During my training I was shown a number of films depicting various DC failings and each time it was about an anonymous carrier and what was described matched very well with events in the final hours of the Ark.

British ships employed very large compartments which ran right across the ship and if one of those took a great deal of water, the free surface would threaten the stability of the vessel as the ship rolled, many tons of water would run from one side of the ship to the other and excessive quantities of free surface would cause capsize. German ships had much greater internal subdivision, both transverse and longitudinal and did not use the broadside messdecks which we knew.

If your vessel is well divided internally, you will encounter far fewer problems. Fires will spread more slowly and the danger from free surface water will be greatly reduced, so your ship will need far fewer safeguards. A ship with large compartments will sport suction in all of them, where a ship which is internally well subdivided will have suction in some.

In the German ships of the time of which we speak, the fan trunckings had water tight sealing valves at all decks and inter-compartmentally. Fire main was available to all parts of the ship. Inter connectors and risers were available in sufficient numbers to be able to re-route electrical circuitry and fast flooding arrangements were established in all magazines and shell rooms, so as far as I can see there were no deficiencies as compared with the ships I served on, even the more modern ones.

As with anything which goes to sea, the efficiency of a department depends on the quality of the crew. With so few ships, the German Navy could afford to be choosey about who would sail in them and I believe a far more stringent selection procedure was employed than in the RN. So I would not think that anything we British sailors could achieve in damage control, could not have been done by the German DC teams. Note should be taken of how well the U-Boat arm dealt with damaged control in U-Boats when far out into the Atlantic. Far too many damaged U-Boats made it home and that was down to the efforts of those who served in them. Whilst the U-Boat arm was a distinct and well defined part of the KM, it should be remembered that it was part of the same navy as that which served in the surface ships.

So with two accessible holes in the bow and the success or failure depending on sealing them, after the shadowers had been shaken off, is there any logic for supposing that this was not done?