Skink anti - aircraft tank Tank AA , 20 mm Quad , Skink was a Canadian Self - propelled anti - aircraft weapon , developed in 1943 - 44 , in response to a requirement from the Canadian Army Overseas . Due to a lack of threat from the German air force , the Skink was cancelled in 1944 after only a few had been built . Development . The development of a fully enclosed quadruple 20mm mounting on the chassis of the Grizzly tank ( Canadian - built M4A1 Sherman tank ) was approved by the Canadian Army Technical Development Board as Project 47 in March , 1943 . In keeping with the tradition of giving Canadian armoured fighting vehicles animal names , the proposed tank was named after the skink , Ontario ' s only lizard . The Canadian Ministry of Munitions and Supply had the turret designed in - house by its Army Engineering Design Branch ( AEDB ) with help from the Inspection Board . The Waterloo Manufacturing Co . in Waterloo , Ontario , was given the task of building a preliminary wooden mock - up . This was completed on 18 September 1943 . The construction of two welded armour pilot turrets was then authorized . The first pilot turret was demonstrated in mid - December . In January 1944 a pilot turret was successfully tested on a Grizzly chassis . Due to the challenges of welding a turret of such a complex shape from Rolled homogeneous armour plate , Dominion Foundries of Hamilton was contracted to produce a fully enclosed cast turret ( the largest armour casting ever made in Canada ) . Originally it was planned to arm the Skink with four 20 mm Hispano - Suiza cannon s and the first prototypes were so - armed . In January 1944 , the 21st Army Group in Europe decided that only British 20 mm Polsten guns would be used ( the Polsten was a simplified derivative of the Oerlikon cannon ) by its units . This required a redesign of the turret , which was completed in April . This change delayed the project by 3 to 4 months , while 21 Army Group ' s reduction in the number of AA guns to be issued to its units led to a reduction in the number of Skink turrets which were required . This dwindled to zero in late July 1944 , when 21 Army Group decided that as the German air force - the Luftwaffe - had been virtually eliminated over North West Europe , there was no longer a requirement for anti - aircraft tanks . The Skink contract was cancelled in mid - August and only three complete vehicles and eight turret kits were completed . Design . The Skink ’ s four 20 mm guns could fire 650 rounds per minute per gun . A modified Oilgear hydraulic traverse with two pumps could rotate the turret at up to 65 degress per second and - crucially for a quick response - - accelerate from rest to 60 degrees in 2 seconds . The guns ’ elevation was also hydraulically assisted so the guns could move at up to 45 degress per second in an arc from - 5 to + 80 . The gunner controlled both elevation and rotation with a joystick , and used a Mk . IX reflector sight . Initially it had been planned to build 300 Skink turrets for the Canadian and British armies . One Skink was sent to Britain for evaluation and was then sent to Europe for field trials with the First Canadian Army . From 6 February to 11 March 1945 , the Skink visited all but one of the Canadian armoured regiments - from Nijmegen to the Cleve area - frequently engaging in actual combat . All units found it to be a valuable asset . However no enemy aircraft presented itself to the Skink ' s guns and its main function was to flush out stubborn pockets of enemy infantry and force their surrender . The remaining Skink pilots and the completed turrets went into long - term storage in Canada where , at some point , they were scrapped . Only some unfinished turret castings salvaged from the firing range survive .