Originally introduced for the Maxim M.G., it replaced the Mk. III wheeled mounting. Brought into use for the Vickers upon its adoption in 1912 as the standard service mountings, it had already been in use with regular battalions for the Maxim since 1909.
The mounting consists principally of a crosshead (a), elevating gear (b) and socket (c), mounted on three legs.It is constructed to give 12 degrees elevation and 25 degrees depression at heights varying from 14½ inches to 30 inches from the axis of the gun to the ground. By arranging the position of the rear and front legs respectively, elevation may be given up to about 43 degrees and depression to 55 degrees. An all round traverse can be obtained.
The crosshead (a) to which the gun is pivoted, is formed with a pivot to fit into the socket (c) and an arm (d) which carries the elevating gear.
The elevating gear, which is actuated by a handwheel (e), consists of an inner and outer screw (right and left-handed) and a nut working within a tumbler (g). The tumbler is split and provided with a jamming bolt (h), by which the wear may be taken up. A chain secures the inner screw to the crosshead to prevent loss while travelling.
The socket (c) is bored to receive the crosshead and is provided with three legs (n), to which the legs are hinged; a jamming block and screw with handle (j) is attached to the front to secure the crosshead in any desired angle of traverse; the block works in a recess in the upper portion of the crosshead and prevents it from rising. Both faces of the rear leg and one face of each front leg are fitted with clutch plates having radial serrations to correspond with similar serrations on the faces of the leg joints. Joint studs with disc spring and jamming handle (e) are fixed to the front legs, by which the legs are securely clamped to the socket in the required position.
The legs (j,k) are of tubular steel, the lower ends being fitted with shoes (m) to steady the mounting on the ground, and the upper ends having a joint with radial serrations mentioned above. The rear leg is provided with a joint pin with nut and jamming handle (t).
On a portion of the periphery of the leg joints numbers are stamped at regular intervals so that when read in conjunction with a zero mark the relative position of the legs to their normal position may be readily seen.
A strap is fixed to the rear leg to secure the three legs during transport.
When firing, the ammunition box is placed on the ground to the right side of the gun.
Weight of mounting ... ... ... 48 lbs. The Vickers gun can be fired from service mountings
The gun could be reversed on the mounting to give greater elevation for use in an anti-aircraft role.
Also, the crosshead could be used with other mountings, such as field-expedient anti-aircraft mounting poles.
Mounting, Tripod, .303-in. M.G., Mk. 5
The Mk. 5 mounting was constructed from a lighter-weight alloy (duralinium) to be predominantly used by airborne forces. Due to the reduction in weight, it required additional support in the form of spikes on the end of the tripod shoes. It was only constructed in limited numbers and did not remain in service for very long. It weighed 23 lbs.
