Secrets of World War II Human Torpedoes (1998– ) Online

There have been submarines around since the American Revolution and the Civil War but they kept sinking. The true submarine was dependent on the invention of the electric engine and the storage battery, which were put to effective use in steel hulls around the turn of the century. By the time of the first World War, Germany was supplementing electrical power with the diesel engine, and the boats were no longer to be lightly dismissed. They sank a Hungarian battleship. The clip you see of the ship rolling over will probably be a familiar one.

In 1940, two midget Italian submarines called "pigs" managed to sink two battleships in the British port of Alexandria in Egypt. They settled to the bottom, a gaping holes in their hulls. Pretty damaging work for three torpedoes manned by six men. The development of the Italian midget torpedoes is briefly and concisely sketched in, with diagrams illustrating the layout and giving the speed, range, and explosive charge they carried. They were manned by two secret elite units called the maiali and the Decima Flottiglia .

The standard tactic was to approach a stationary ship, attach a magnetic clamp to both sides of the hull underwater, with a line connecting the two, and the charge directly in the middle of the line, hanging under the ship's keel, the most vulnerable part of the ship.

But the techniques varied. Some submarines carried detachable warheads. And individual frogmen carried limpet mines that they attached magnetically to ship. They were pretty clever. The mines had tiny propellers that remained inactive until the ship got underway, and then the propellers would spin and record the time until the detonation. One German submarine and a handful of Italian manned torpedoes managed to eliminate for a time every British battleship in the Mediterranean. Some were launched in secret from an Italian freighter moored in a neutral Spanish port, just off Gibralter. There's a feature film about this, "The Silent Enemy" (1958).

The Japanese deployed five midget submarines with two-man crews during the 1941 attack at Pearl Harbor and in Sydney Harbor. All were lost, and some of the crew taken prisoner. Late in the war the Japanese used suicide human torpedoes, analogous to the Kamikaze. They did some notable damage but most were lost and of course by that time there was no stopping the massive array of Allied forces on their way to the home islands.

The episode is mostly made up of newsreel and combat footage. The narration by Robert Powell gives us whatever information we need, so there are no talking heads.