M45 Quadmount

Matt recently had the opportunity to visit the excellent Menorcan Military Museum at Es Castell, on the Spanish Balearic Island of Menorca. The museum is well worth a visit with some very rare and extremely interesting weapons on display. 

M16
An M45 mounted on a M16 half-track during World War Two (source)

The M45 Quadmount was developed by the W.L. Maxson Corporation for the US Army. It mounted four .50 calibre M2 Browning Heavy Machine Guns on a lightweight, rotating powered mount.  I recently had the opportunity to take a closer look at an M45 while visiting the Menorcan Military Museum.

Introduced in 1943, the M45 was capable of 360 degrees of rotation and 90 degrees of elevation. It was manned by a three man crew: two loaders, who loaded the M2 Browning’s 200-round belt drums, and a gunner.

The M45 was extremely versatile and could be mounted on a number of trailers and vehicles including the M20 and M17 trailers and the M16, M17 and M51 half-tracks.

M45 TM
Diagram from the M45’s manual showing the layout and some of the Quadmount’s parts (source)

The gunner sat on a canvas seat inside the M45, between the two pairs of guns. He controlled the aiming of the guns with two control handles and aimed the M45 through a reflex sight which was mounted to a sight bar.

The M45 was powered by two 6-volt batteries and weighed approximately 2,400lb (1,090kg). The gunner was protected by an armoured plate at the front with two hinged armour plates either side of the M1X reflex sight. The M45 mounted four M2 TT (Turret Type) varriant machine guns – these were fired by solenoids. All four of the guns could be fired at once but gunners normally alternated between the upper and lower pairs in order to allow the guns to cool and loaders to replenish the drums.

US_Army_M16_MGMC_AA_Half-track
An M45 mounted on an M17 half-track during the Korean War (source)

When all the guns were fired together the M45 had an impressive rate of fire of approximately 2,300 rounds per minute. The Quadmount saw action throughout World War Two, the Korean War and in Vietnam. However, with the beginning of the jet age the M45 became increasingly obsolete in the anti-aircraft role. It continued to be used against ground targets with many mounted on vehicles to create ‘gun trucks’.