Green Mace Heavy Anti-Aircraft Gun
QF 127/58 SBT X1 was developed in 1956 by Vickers. The goal was to be able to target Soviet fighter jets and possibly bombers. The platform had 2 x 14 round drums feeding Folding Fin Discarding Sabot into the 102mm gun. The engagement range was 25,000 ft and the maximum range was 30,000 feet, but it would take the rounds just under 10 seconds to get there.
Specifications and Capabilities
The specs looked great at first: This 28-ton 6×6 behemoth could be operated by a single person. The calibre and muzzle velocity of this machine made it a fearsome anti-aircraft (and possibly anti-armour) platform, and the rate of fire was 75 RPM, although the system was capable of up to 96 RPM!
However, the Green Mace needed two trailers in support: One supplying the power and one carrying the ammunition. The wheels had to be removed to put the gun into battery. And because of that fearsome rate of fire, all rounds could be fired in under 40 seconds and it would take the crew between 10 and 15 minutes to reload the two drums!
Operational Challenges and Cancellation
Finally, during testing, the Green Mace experienced a fault every 12 rounds on average: It jammed frequently and the high recoil and cyclical rate of fire regularly tore bits off the whole assembly!
The project was cancelled the following year (1957), with the advent of SAMs and the handover of air defence duties from the Army to the RAF.
-RBM.
