World War II Database

Contributor: C. Peter Chen

This article refers to the entire Renraku-tei-class; it is not about an individual vessel.

ww2dbaseThe Japanese Army began working on special attack boats in Mar 1944, largely under the direction of Lieutenant General Yoshiaburo Suzuki. The design was developed at Himeji near Kobe, Japan, and the first example was tested in Tokyo Bay in Jun 1944. Designated Renraku-tei ("Liaison Boats") or sometimes Maru-ni ("Large Boats"), they each carried two 120-kilogram depth charges; theoretically the boats were to approach the enemy, drop the depth charges, and flee at a speed of 30 knots to avoid being caught up in the explosion, but in actuality these boats were indeed special attack weapons as few could escape unharmed. These boats were organized into units generally referred to as Akatsuki ("Dawn") Regiments in Sep 1944. Each regiment typically had 100 boats.

ww2dbaseThe Army had about 800 Renraku-tei boats in the Philippine Islands by late 1944. Before dawn on 10 Jan 1945, a group of Renraku-tei boats conducted an attack in Lingayen Gulf, Philippine Islands, damaging five LST landing ships and sinking two LCI gunboats. On Okinawa, both Navy and Army special attack boats got their chances to attack, sinking landing ship LSM-12 on 31 Mar 1945 and gunboat LCI(G)-72 on 3 Apr; nevertheless, far more Shinyo and Renraku-tei boats were destroyed than the number that got through American picket lines.

ww2dbaseThe Japanese Army built about 3,000 Renraku-tei special attack boats. At the end of the war, 700 boats were deployed in the Japanese home islands.

Renraku-tei-class Motor Torpedo Boat Operational Timeline