This being 1940 the German U-Boat torpedoes would be equipped with either contact fuses or (very poorly working) magnetic fuses.
The magnetic fuses were designed to explode the torpedo underneath the ship's keel, which is devastating to modern steel ships, as it would create a void and cause the ship's spine the break. Ships are designed to be, unsurprisingly, supported along their whole lengths, they don't deal well by that support suddenly disappearing, along with a large shockwave slamming into the keel.
How a wooden ship would react to that is a good question, they were much smaller and thus might be more able to survive the void. But of course magnetic fuse wouldn't trigger on a predominately wooden ship, so it's kinda moot.
Contact fuses would work against wooden ship, and might even work better than against steel ships. Contact fuses tended to bounce off the hull if they impacted obliquely instead of head on, but since wood is much softer than steel, the fuse might ram into the side of the ship more readily and go off at a greater angle. In this case the torpedo warhead detonates in contact with the hull, under the waterline, and you would at minimum have catastrophic flooding. Wooden sailing ships like that are not compartmentalized so any such hit would be pretty much guaranteed sinking if the ship survives the explosion in the first place. Again, it'll be liable to break the ship's spine, the most important spanwise members run along the keel, right where an underwater torpedo would hit. So a galleon like that might break in two with a hit.
But in both cases the German torpedoes required a certain minimum distance before they armed themselves. Depending on the type, it was 100 to 300 meters. The ones used on submarines generally were either 150 meters (G7a) or 250 meters (G7e). Later war acoustic homing torpedoes had 1000 meter arming distance, but these wouldn't home in on sailing ships, and were much later than 1940.
The magnetic fuses were designed to explode the torpedo underneath the ship's keel, which is devastating to modern steel ships, as it would create a void and cause the ship's spine the break. Ships are designed to be, unsurprisingly, supported along their whole lengths, they don't deal well by that support suddenly disappearing, along with a large shockwave slamming into the keel.
How a wooden ship would react to that is a good question, they were much smaller and thus might be more able to survive the void. But of course magnetic fuse wouldn't trigger on a predominately wooden ship, so it's kinda moot.
Contact fuses would work against wooden ship, and might even work better than against steel ships. Contact fuses tended to bounce off the hull if they impacted obliquely instead of head on, but since wood is much softer than steel, the fuse might ram into the side of the ship more readily and go off at a greater angle. In this case the torpedo warhead detonates in contact with the hull, under the waterline, and you would at minimum have catastrophic flooding. Wooden sailing ships like that are not compartmentalized so any such hit would be pretty much guaranteed sinking if the ship survives the explosion in the first place. Again, it'll be liable to break the ship's spine, the most important spanwise members run along the keel, right where an underwater torpedo would hit. So a galleon like that might break in two with a hit.
But in both cases the German torpedoes required a certain minimum distance before they armed themselves. Depending on the type, it was 100 to 300 meters. The ones used on submarines generally were either 150 meters (G7a) or 250 meters (G7e). Later war acoustic homing torpedoes had 1000 meter arming distance, but these wouldn't home in on sailing ships, and were much later than 1940.
Statistics: Posted by x-viila — 01 Jun 2025 05:34