In February 1940, two Type 7 long-barreled howitzers were moved to the Kotō fortress in Manchuria to strengthen Japanese defenses in the event of a Soviet attack. The Japanese army had eight fortresses built along the border with the Soviet Union, of which the Kotō fortress on the Ussuri River was the strongest. Large-scale fortifications, similar to the Maginot Line, were guarded by the 4th Border Guard Unit. The 1,400-strong crew had two batteries of field guns and howitzers, two Type 90 240 mm railway guns, and one experimental 41 cm howitzer. When the Soviets attacked the Japanese positions around the Kotō fortress in Operation August Storm in 1945, the entire fortress crew and all guns were lost.