Ship sinking times: A post-war analysis

[Captain Nemo]

I am currently reading a book called "Survivors - British Merchant Seamen in the Second World War". In one of the chapters it mentions the following:

"A post-war analysis of the time taken to sink, from all causes, by a sample of 296 ships where survivors had given clear information on this point found that 69.6 per cent sank in the first quarter of an hour after being hit, 9.5 per cent in the second quarter of an hour, and a further 9.8 per cent before an hour had elapsed. Only 11.1 per cent remained afloat for more than an hour. A different study of 110 British ships sunk by torpedoes from submarines between 1940 and 1943 found 47.7 per cent sank in the first quarter of an hour, 12.6 per cent in the second quarter of an hour, and a further 11.7 per cent before an hour had elapsed. Some 27.9 per cent remained afloat for more than an hour, of which one or two did not sink for several days. Where ships stayed afloat for several hours, the final plunge might occur very rapidly indeed if it were brought about by a second torpedo or the collapse of a vital internal bulkhead".

It does go on to say that these figures might not be entirely accurate because of the stress the seamen were under when abandoning ship etc. However, I thought I'd post them because there has been several debates on this forum with regard to sinking times of ships in SH3.

Nemo

[Kpt, Otto]

I have often wondered about the sinking times in SH3 and GWX.

There was once where I torpedoed a small frieghter hiting it with two torpedoes and it didn't sink. I was there for two hours!! I put a further two torps into it and it still didn't sink!

During the post mortem as it were and bear in mind I am no expert in the games damage model I concluded that it must have been down to (in game) where the torpedoes strike. On this occasion all my torpedoes struck roughly in the same place therefore I could only come to the conclusion that the game doesn't see that as four strikes and rachet up the damage but rather as one compartment flooding hence why it didn't sink.

With this in mind I noticed that if I fire two torpedoes in salvo at a similar ship with a slight spread angle one will hit forward and one either amidships or aft. In this instance the ship sinks in around five minutes. This is probably because its see's two compartments flooding. If however I fire two torpedoes and they strike amidships then the ship will take longer to sink, in most cases about half an hour to 3/4 of an hour. Again here it perhaps only see's one compartment flooding.

If I only fire one torpedo then depending on where it hits I can be there for upto an hour however for me most ships take two torpedoes to sink them. (Again only one compartment flooding)

I think its just the way SH3 handles its damage model. :hmm: In terms of speeding up the sinking times, perhaps it would have diverse effects elswhere and so a compramise has perhaps been made? :hmm:

My thoughts are that it is probably as near to being correct as it could be. :hmm:

[papa_smurf]

This is a valid point, as I too have found ships in SH3 and GWX sink at different times. Even when I have had realistic sink times selected on game difficulty, I've hit ships with just one torpedo, and then has it sink within 2-5 minutes. This was most often in calm weather, which is just plain silly.
If this was a real life situation, even on a "small" ship, say 2000 tons, the crew would surely be able to stop any flooding and keep it afloat for more than 2-5 minutes.
I suppose I could keep on complaining, but I won't, I'll just have to put up with it.

[seafarer]

Definately hitting the same spot more then once incurs minimal additional damage. The hit point model in the stock game just works that way. But 2 hits spaced well apart is often more then enough for most cargo ships.

In terms of the real world post-hoc analysis, it seems to make sense to me. WWII era freighters were usually single hull ships. And being general purpose cargo haulers, they were largely just big open spaces within the hull. Rip a bus sized hole in the side of a cargo hold, or a large open area like a boiler room or engine room (steam piston engines require huge open spaces) and the ship would loose bouyancy fast.

Of course, cargo would impact things somewhat - what it was, how densely it filled the space, that sort of thing. And the cold NA water tended to make steel brittle, so cracks would propogate, making damage control difficult.

[Brag]

I find that GWX sinking times match pretty close those quoted by Capt. Nemo.

In the game if the target's speed drops immediately at the moment it get's hit, you can be pretty sure it will sink within 1/2 hour and doesn't require additional help.

[Captain Nemo]

In my experience if you hit the ship in the bow area then they tend to go down within 15-30 minutes. When doing this they tend to maintain a good speed right up until they are about to take the final plunge.

Nemo

[TarJak]

The one thing missing from the analysis is the number of torps fired and the number that hit prior to sinking. Most attacks used more than one torpedo where available to be sure of a sinking so without that crucial data the comparison is relatively meaningless other than to say that if you get at least one hit you can expect that most of the time the ship will sink within about 20-30 mins. This is certainly my experience and I practise the rule that anything worth shooting is worth shooting twice.

[Captain Nemo]

I agree Tarjak, but it would be difficult for any merchant seamen to know exactly how many times a ship is hit when they are abandoning ship and trying to save themselves and others from a sinking ship. However, it does mention in the last sentence that the final plunge might be brought about more rapidly by a "second" torpedo.

Nemo

[Brag]

anti-poll bump

[OuNiS]

Are you this Otto?
Famous Otto?

Ok if you answer yes, then you should know that about 70 years ago you have try to sunk ship named Elmblank (5156 BRT). You fired to her two torpedoes and shot about 90 shels and she still haven't sunk. Your kamerad from U-47 shot all of ammo.
Result? The ship fifteen years old tramp haven't sunk.

I think you should think about it...

[Kpt, Otto]

Originally Posted by OuNiS

Are you this Otto?
Famous Otto?

Ok if you answer yes, then you should know that about 70 years ago you have try to sunk ship named Elmblank (5156 BRT). You fired to her two torpedoes and shot about 90 shels and she still haven't sunk. Your kamerad from U-47 shot all of ammo.
Result? The ship fifteen years old tramp haven't sunk.

I think you should think about it...

No! I assume you mean Otto Kretschmer??? He died in 1998:

http://en.wikipedia.org/wiki/Otto_Kretschmer

I have read and studied his strategies and methods for attack and found them interesting. In my opinion he was the Red Baron of the sea's!

Im just an English fellow who enjoys studying history and loves the game!

The story you presented was very interesting and throughout the books I have read and programes I have seen I always enjoy hearing moments in history, the thoughts of people , that otherwise would have slipped away. Often these moments / experiences one would not have believed but for the eye witnesses who spoke of them.

:hmm:

of course you could be pullin me leg!!! :rotfl::rotfl:


Famous Otto? Im working on it, Im promised a type VII soon!

[Stierlitz]

anti-poll bump

[OuNiS]

Originally Posted by Kpt, Otto

No! I assume you mean Otto Kretschmer??? He died in 1998:

http://en.wikipedia.org/wiki/Otto_Kretschmer

Yeah I know...
But your nick and number of your type II uboat told me that maybe you have to be him in virtual world of SH3.

Originally Posted by Kpt, Otto

I have read and studied his strategies and methods for attack and found them interesting. In my opinion he was the Red Baron of the sea's!

You right. But he was defeated by another great man of the seas Donald MacIntyre, before 1943 (the hotest times for uboats).

Ok but main post is about ship sinking times and I think that it is not so bad in SH3 + GWX. I purposely told you the story about U-99 and Elmbank to ilustrate that many things may caused that torpeded ship sunk slow or fast and I think GWX very good simulate it.
In convoy HX72 many ships sank very fast but it was exceptions and Elmbank is one of them.

Originally Posted by Kpt, Otto

Famous Otto? Im working on it, Im promised a type VII soon!

I wish you good hunting Kaleun!

[Kpt, Otto]

Yeah I know...
But your nick and number of your type II uboat told me that maybe you have to be him in virtual world of SH3.

You are right on this one! I did pick the name and u-boat number/type for this reason.

Quote:
Originally Posted by Kpt, Otto
I have read and studied his strategies and methods for attack and found them interesting. In my opinion he was the Red Baron of the sea's!

Quote:
Originally posted by OuNiS
You right. But he was defeated by another great man of the seas Donald MacIntyre, before 1943 (the hotest times for uboats).

Ok but main post is about ship sinking times and I think that it is not so bad in SH3 + GWX. I purposely told you the story about U-99 and Elmbank to ilustrate that many things may caused that torpeded ship sunk slow or fast and I think GWX very good simulate it.
In convoy HX72 many ships sank very fast but it was exceptions and Elmbank is one of them.

Yes Donald MacIntyre, I read his book "U-boat killer" isbn 0-304-35235-7, its a great book and he was just as skilled as Kretschemer was. He in fact speaks quite highly of him.

Back to the thread... I agree ship sinking times in SH3+GWX are reasonable given the damage model and the way it seems to work. Your example was a good one in that it shows that sometimes not every ship will callapse under a torpedo hit and can sustain and survive serious damage. In this case several hits!

Further examples are written in a book called "Convoy" my Martin Middlebrook isbn 0-304-36578-5 which describes the battles surrounding convoys SC.112 and HX.229. In pages from 187 to 192 it describes three ships torpedoed during the night which took over four hours to sink, these ships were, Irenee du Pont, Southern Princess, and Nariva. These long sinking times I think were more an unusual event rather than the norm and were a result of many factors including what cargo they carried. They may also have been affected by the way in which they were hit or the performance of the torpedo which didnt always run straight or at the right depth or explode with the right explosive force. The torpedos were often troublesome

I think the analysis shown in Captain Nemo's book is as close to acurate as we could get and in SH3+GWX I think this is reflected very well because if I think about the ships I have sunk in this latest career the ship sinking times are similar to that of the book. This is remarkable because the damage model I dont think takes into account all the various factors and the GWX team I think have done a great job in bringing this to the game albeit probably in a differant way because of the damage model limitations but the result is to me is the same. I for the first time get to experience the frustration of a u-boat captain and crew who risked their lives to torpedo a ship get depth charged and then come to periscope depth only to find a burning ship still on the surface just like in Das Boot! Luckily for me I can switch off my computer but for them it was real.

I also get ships that sink in five / ten or fifteen minutes. I can think of no other subsim that can do this variable damage model although I have not played SH4 yet.

In all I think its great

OuNiS - Thank you, I also wish you good hunting!!!!