[2] The Type 45 was developed after the Russo-Japanese War showed the value of heavy caliber howitzers and mortars when attacking strongly fortified enemy positions.

Setup required considerable time and the use of a crane to raise the heavy gun barrel onto a firing platform.

[citation needed] The gun could fire an armour-piercing shell with a muzzle velocity of 400 metres (1300 feet) per second to a maximum range of 10 km (11,000 yards).

In the Second Sino-Japanese War, there were fewer opportunities to use the Type 45, as Japanese forces rarely had to assault a position so strongly fortified that lesser caliber field artillery could not be used instead.

[5] However, with the start of World War II, the Type 45 was deployed in the Battle of Hong Kong against entrenched British landward defenses.