SD:Ram II OP (140mm)

 is a Canadian Artillery unit.

Overview
An indigenous Canadian design created in response to a shortage of cruiser tanks in Canadian service in 1941, the Ram tank was based on the M3 Lee interim tank created by the United States. It was largerly a learning experience for the Canadian industry, which did not produce a tank beforehand. The design of the M3 was heavily modified and ultimately only the lower hull, engine, drive train, and transmission were retained. The upper chassis was a Canadian design, providing better armor and reduced profile than the M3 and accommodating a fully rotating turret mounting a QF 6-pounder gun. The prototype was completed in November 1941, with serial production beginning shortly. Although over 2000 tanks were produced, the Ram was not used as a line tank, due to inferior armament and protection, as opposed to the Sherman, which became the standard tank of North American forces. RAM II were used in various other roles as observation post vehicles and Armoured Personnel Carriers along with providing the chassis for the Sexton (Can)

The artillery observer tank was modified to act as a mobile observation post, with its gun removed and two Wireless Set No. 19 radios fitted with a No. 58 set. OP tanks were converted from the last 84 Rams to roll off the production line in 1943. Thiis RAM II directs off-map BL 5.5-inch Medium Gun Artillery to a given location. BL 5.5-inch Medium Gun were organized into Medium Regiments each with 8 guns. These Medium Regiments were organized into Army Group Royal Artillery.