How a Modern Torpedo Sinks a Ship with One Hit

By Harold Hutchison,We Are the Mighty

If you’ve seen any submarine-themed movie, whether it’s Hunt for Red October, the classic Operation Pacific, or Crimson Tide, you understand the severity of an incoming torpedo. Anyone who knows naval history knows that torpedoes are lethal to ships – just look at what they did to the liner Lusitania, the aircraft carrier USS Wasp (CV 7), and a host of other ships.

Back through World War II, the primary way torpedoes did their damage was with a direct hit. The impact of the torpedo on a ship’s hull would drive a firing pin that sets off a warhead. The hope here is that the blast punches a hole in a ship, allowing water to flood in, causing the ship to list to one side or the other and, eventually, capsize. Generally, this approach worked well, but it could take many direct hits to do damage enough to sink a vessel. The Japanese battleship Musashi, for example, took over twenty hits from Mk 13 air-dropped torpedoes before she went down.

One of many air attacks carried out on HIJMS Musashi during the Battle of Leyte Gulf. It took over 20 torpedo hits to put that ship on the bottom. (US Navy photo)

This was a problem — as defensive anti-aircraft capability developed, planes launching torpedoes needed to do so from higher altitudes, at faster speeds, and from further away in order to survive. This was not conducive to scoring the many hits you needed to sink the enemy ship.

In fact, with rare exceptions, the only vessels that use heavy anti-ship torpedoes today are submarines. The torpedoes used by planes and ships are often less than 13 inches wide and hold warheads packed with less than 100 pounds of high explosive. They’re not that good against surface ships, but you don’t need much to sink a sub that’s a few hundred feet below the surface of the ocean.

The heavy torpedoes themselves have also evolved, and not just in tracking capabilities.

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