Japanese Torpedo Boat Tomozuru - The Tomozuru Incident

The Tomozuru Incident

In February 1934, Tomozuru joined the 21st Torpedo Flotilla at Sasebo.

• 01:00, 12 March 1934, Tomozuru departed from Sasebo for a night torpedo exercise with the Tatsuta and Chidori (千鳥?).
• 03:25, because of stormy weather, the Tatsuta ordered the other 2 boats to return to base.
• 03:58, radio contact lost with Tomozuru. Loss of power?
• 04:12, Tomozuru's lights disappeared, presumably this is when she capsized.
• 14:05, a rescue plane discovered the capsized Tomozuru drifting.
• 07:00, 13 March 1934, Tomozuru was towed by Tatsuta back to Sasebo. 100 crew were lost.

The instability of the Chidoris arose from Japanese efforts to circumvent the various naval treaties. They had designed small vessels of around 600 tons, but with the weaponry of a destroyer of twice the displacement. Weight had been saved by lighter construction but gun systems remained complex and heavy. After the launch of the lead ship, its high centre of gravity - even higher than feared - had been noted and efforts made to remedy this. High-speed sea trials showed her to be unstable, however, and further efforts were made to rectify the problem by adding bulges to the hull. Eventually Chidori satisfied the examiners and she was commissioned and the construction of the class, including Tomozuru, proceeded. At the time of her loss, the Tomozuru was low on consumables such as fuel or water that would have ballasted her and lowered her centre of gravity. On the other hand, munitions were fully loaded, so the situation was significantly worse than on her sea trials.