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karamazovnew · 07-23-10, 09:55 AM

Actually...

The quantity of water that will rush through the hole in the hull depends on 3 things:

- size of the hole: most torpedo hits will create very large holes in the hull bigger than 2 meters squared. These CAN NOT be fixed on the go from the inside. The ship would need to stop, a Macarov patch would be applied from the outside and the gap plugged with cement from the inside.

- how far under the waterline the hole is: the further down it is, the higher the water pressure. Captains will usually pump out all ballast to keep the ship as high in the water as possible.

- position of the hole, speed of ship and turning rate: a hole at the forepeak (in front of the first bulkhead) would not affect the ship much. If the front bulkhead is affected, it's actually better to stop and reverse the ship. But, if the hole is near the waterline, going moderately fast and ballasting the stern would bring the affected section out of the water Now in all cases of holes except on the bow section, it's actually better to go as fast as you can. This depends a lot on the shape of the hull. Faster speeds will disrupt the laminar flow around the ship. On some holes it's best to have laminar flow (on narrow vertical breaches) while on others it's best to have turbulent flow (low pressure). Constantly turning into the affected area would do 2 things: rise the level of the hole and reduce pressure in the area. However, if the ship continues to take on water, the ship might capsize. A hole near the keel will either break up the keel in rough weather or at high speed and the intake of water would practically be impossible to control. You'd have to shut off that compartment and allow it to fill up to the waterline if you can't patch it with a Macarov. The type of cargo that you carry in that compartment will dictate if it's better do dump it overboard or not.

So as you can see, simply reducing speed isn't always the best way.

Now, in a mid-Atlantic 1940's situation, if you're hit by a torpedo near the keel or a bulkhead, it's pretty much game over.

07-23-10, 09:55 AM	#7
karamazovnew The Old Man Join Date: Mar 2009 Location: Bucharest, Romania Posts: 1,403 Downloads: 151 Uploads: 0	Actually... The quantity of water that will rush through the hole in the hull depends on 3 things: - size of the hole: most torpedo hits will create very large holes in the hull bigger than 2 meters squared. These CAN NOT be fixed on the go from the inside. The ship would need to stop, a Macarov patch would be applied from the outside and the gap plugged with cement from the inside. - how far under the waterline the hole is: the further down it is, the higher the water pressure. Captains will usually pump out all ballast to keep the ship as high in the water as possible. - position of the hole, speed of ship and turning rate: a hole at the forepeak (in front of the first bulkhead) would not affect the ship much. If the front bulkhead is affected, it's actually better to stop and reverse the ship. But, if the hole is near the waterline, going moderately fast and ballasting the stern would bring the affected section out of the water Now in all cases of holes except on the bow section, it's actually better to go as fast as you can. This depends a lot on the shape of the hull. Faster speeds will disrupt the laminar flow around the ship. On some holes it's best to have laminar flow (on narrow vertical breaches) while on others it's best to have turbulent flow (low pressure). Constantly turning into the affected area would do 2 things: rise the level of the hole and reduce pressure in the area. However, if the ship continues to take on water, the ship might capsize. A hole near the keel will either break up the keel in rough weather or at high speed and the intake of water would practically be impossible to control. You'd have to shut off that compartment and allow it to fill up to the waterline if you can't patch it with a Macarov. The type of cargo that you carry in that compartment will dictate if it's better do dump it overboard or not. So as you can see, simply reducing speed isn't always the best way. Now, in a mid-Atlantic 1940's situation, if you're hit by a torpedo near the keel or a bulkhead, it's pretty much game over.