The Browning Quad Machine Gun saw service with the Royal Artillery as both the Self Propelled M16 Halftrack and as the trailer mounted M51. The gun used was the M2HB (air cooled, heavy barrel version) in the M45 Quad Mount. The gunner sat in an armoured cab between the 2 pairs of guns.
The M16 was based on the chassis of the M3 Halftrack. The trailer mounted version, the M51, used the M17 trailer. For Operation Plunder, the crossing of the Rhine, in 1945, Light Anti-Aircraft Regiments were to be issued with two M16’s per Troop. This did not apply to to LAA in the Anti-Aircraft Brigades. In the event, some units did not receive their M16’s until the operation was nearly over. At least one Regiment, 27 Light Anti-Aircraft, had six M51’s.
The War Establishment for a Light Anti-Aircraft Battery (Mobile) 1945 gives two Troops each of 4 x 40mm Bofors and 4 x Browning Quad Machine Gun. These were M51’s in a towed Troop and M16’s in a Self Propelled Troop.
Specifications M45 Quadmount
| Weight | 2,396 lbs (1,087 kg) |
| Barrel length | 5 feet 3 inches (1.6 m) |
| Elevation | -5° to +90° |
| Traverse | 360° |
| Rate of Fire | 575 x 4 = 2,300 rounds per minute |
| Muzzle Velocity | 2,900 feet per second (890 metres per second) |
| Firing Range (effective) | 4,900 feet (1.5 km) |
| Firing Range (maximum) | 1.1 miles (1.8 km) (horizontal) 1.6 miles (2.5 km) (maximum) |
Specifications M16
| Weight | 9.9 tons |
| Length | 21 feet 4 inches (6.5 m) |
| Width | 7 feet 1 inches (2.16 m) |
| Height | 7 feet 8 inches (2.34 m) |
| Crew | 5 |
| Armour | 12 mm (0.5 in) on sides and front |
| Operational range | 175 miles (282 km) |
| Maximum speed | 42 miles per hour (67 km/h) |