Japanese Suicide Boats

The following U.S. intelligence reports on Japanese suicide boats were published in Enemy on Luzon: An Intelligence Summary:

NAVY SUICIDE CRASH BOATS:

Japanese suicide crash boats manned by Naval personnel were found in a tunnel on Corregidor. The boats were loaded on small carts which were mounted on rails running from the tunnel to the beach where they were to be launched.

The Navy Suicide Crash Boat was 16 feet 8 inches long and had a beam of 5 feet 8 inches. The hull was plywood construction throughout and was powered by an automotive type, 6-cylinder, in-line, gasoline engine. The explosive charge was built into the hull of the boat. This last feature was the main difference between the Army and Navy suicide boats.

The Type 98 explosive charge weighed 640 pounds and was located below the deck forward of the cockpit. The charge could be fired by three methods: 1) electrically on impact; 2) electrically by closing a switch; and 3) by use of a pull igniter.

From the disposal point of view, the boat was dangerous to anyone unfamiliar with the circuit and switch details. It would also have been simple to rig this boat as a booby trap either electrically or through the pull igniter.

The boat carried a big charge that would be effective against ships. The only defense that a ship had was, as in the case of the suicide plane, accurate gunfire.

ARMY SUICIDE CRASH BOAT:

Japanese suicide boats, to be manned by Army personnel, were recovered at Lingayen Gulf, Luzon. These craft were the principal weapon of the Japanese Gyoro (“fishing”) battalions.

The army suicide boat was made of plywood with a length of 18½ feet and a beam of 5 feet 10 inches. It was decked with a forward hatch leading to the engine and has a cockpit aft. The boat was powered with a 6-cylinder Chevrolet automotive engine, about 85 horsepower. The maximum speed of the craft was estimated at 35 knots. The fuel capacity was about 56 gallons.

The two 120 kg depth charges were mounted on racks abreast of the cockpit. The charges could be either dropped close aboard or released when the boat crashed into the ship. At least one attack of the former type was made, resulting in damage to a merchant ship during the Luzon campaign.

Although parts of the release mechanism were not available, the operation is believed to have been as follows: the charges were fitted in the racks and held by an arrangement of slings and bars. Rods fitted to extend beyond the bow would be driven back releasing the charges during a collision with another ship. However, the coxwain could place a crossbar forward to release the charges.