20 mm Type 98 (1938) Anti-tank Anti-aircraft Gun

The Type 98 is the only medium calibre anti aircraft gun known to have been used by the Japanese Army. The weapon is based on a modified Hotchkiss mechanism and is select fire, gas operated. The weapon is mounted on wooden wheels with iron rims. It is relatively light and manoeuvrable and can quickly be brought into action from the travelling position. The gun is mounted on a carriage which permits firing from the wheels. With the wheels removed the weapon is supported on three outriggers giving the piece 360 degree traverse. This weapon features twin recoil cylinders which can be adjusted for length of recoil. There is a graduated scale fastened to the adjusting screw for setting recoil lengths. Respirators are located at the forward end of the cylinders to allow air to be drawn into the cylinders during recoil. An equilibrator unit fits into a bell housing which in turn mounts the equilibrator springs, 360 degree traverse bearing and the azimuth indicator gears. The gun has a blued finish. There are no sights with the weapon. The gunners seat has a green painted number "30" on it. A silver plate is riveted on the side of the carriage with the numbers "53 1061" stamped on it. The wooden spoked wheels are painted jungle foliage green.

The weapon was collected from Rabaul by the 5th Military History Team, transported to Australia by the SS Salamaua and unloaded in Sydney on the 18/01/1946.