Seen it happen in SH3. I hit a passenger cargo with a couple of torps and it split in two and both halves remained afloat. I got the "She's going down" message so got the credit for the sinking even though it didn't sink as such. They remained afloat for the rest of the patrol, as occasionally I would pass back near the site where the red ship sunk icon was on the map and they were still there but both parts had drifted away from each other by some distance. I'll have to dig through my screen shots and if I have them will post them on this thread.

Nemo

Or it might be this:
SPACE BATTLESHIP YAMATO
http://img215.imageshack.us/img215/3208/9c12d2.jpg

Very,very sexy.You could win the war with that thing :D

Unsinkable Medium Cargo
 

The WW1 split was HMS Zulu & HMS Nubian two Tribal Class DD and recommissioned as HMS Zubian.

My problem is the Medium Cargo in GWX it has no intention of sinking as a class not as an anomaly. There entire reason to exist seems to be to steal torps from your tubes. A one hit kill is a triumph! 2 hit normal. 3+ not unknown.

I'm also less than thrilled when escorts take a torp and live, few did usually only when hit on extreme ends blowing off bow or stern but watertight enough not to sink.

Would that happen to be the Taffelberg? Stuck a mine, limped home, then welded together i think. I maybe wrong though.

The post just above yours identified them correctly, Though neither one was actually split in half. One had her bow blown off, the other her stern.

On the other hand in WW2 HMS Javelin lost both stern and bow, but survived to be rebuilt.

And here's what you do with a split-in-two tanker.
http://www.subsim.com/radioroom/showthread.php?t=170723

Classic :sunny:

nm...

hmmm you just gave me a good idea for some modders. if a lucky shot managed to hit the props then once the ship comes to a stop the ship could be abandoned (as in the men disappear off the decks flare is launched and lifeboats are deployed etc). it happened once or twice when i fired a quick shot at a destroyer and running depth was slightly off. the torpedo goes right under the bow along the beam and explodes under the props but causes minimal flooding and the ship maintains operations. would be nice to see it abandoned and its AI turned off if it comes to a dead stop due to lack of props or destroyed boilers. i am sure in real life any ship with such heavy damage would want to move ship asap.

just a nice idea i think if any one wants to expand on it :D would like to see it in game

Well this could be a few things at play.
First: You might not put a big hole in the ship, you just cause big cracks or you put a small hole in and they patched it up. The cargo could be the reason but the game doesn't simulate this. Contained flooding could be why they list or settle but don't sink. It could be a bug in the game.

But from what I have seen of GWX, whats really happening is the fact that flooding and not damage is what sinks ships. Try to hit the bow while they move, the force of the ship moving will press water into the ship. After that they should be slow, take your time and spread out the damage to both sides of the ship and both ends. If you see them in a convoy, take your time to line up a shot that will disable them if not sink them then wait for night and then use your deck gun from range while moving fast and turning. Take out their guns, if your movements are fast and random you should have enough time to destroy their guns, use manual targeting of the deck gun.
If you wish to use just torpedoes then as I said before, spread out the damage use magnetics to maximize damage. If the ship isn't moving aim for cargo hauls or other large rooms, your looking for low part of the ship most likely the bottom deck somewhere fore of the stack tower and superstructure.
But if at all possible, use your deck gun to start fires and do damage to the deck, top cargo, cabin, and all manner of other structures. This should reduce the rate they repair their ship and pump water out. That is why they had deck guns...to finish ships off.

Good luck.

The tanker MV SAN DEMITRIO was one of these 'tough cookies', in 1940 pounded by the 'Admiral Sheer', she was abandoned in mid atlantic, but was eventually reboarded, patched up & sailed home. She was sunk 2 years later by U404.
http://en.wikipedia.org/wiki/MV_San_Demetrio

It was made into a pretty good film as well:

http://uk.imdb.com/title/tt0039797/