M55 Self Propelled Howitzer

The M55 was an American fully enclosed and armored self-propelled artillery based on the M53 155 mm assault gun. It had a 203.2 mm howitzer which could traverse 30° left or right, carrying only 10 rounds of ammunition. The gun had a maximum range of 16,916 meters (10.51 miles) with a rate of fire of one round every two minutes. The M55 armor was light, 25 mm maximum, but sufficient to protect the crew from indirect artillery hits or small arms fire.

The M55 used components of the M47 Patton tank, but the automotive aspects were reversed. The engine was mounted in the front and drove through a front-drive sprocket. The driver's cupola is visible on the front left of the turret, and spare track blocks were stored on the turret front.

The M55 was used during the Vietnam War, and subsequently withdrawn from service in the US military.