In 1874, Engineer Battery was originally intended to mount a 9-inch RML gun; however, a 10-inch RML was ultimately installed in an open, shielded emplacement. The mismatch between gun and carriage led to structural deficiencies, and subsequent trials demonstrated that the shield could not be regarded as safe when the gun was fired at the extreme limits of traverse on either side. The weapon was subsequently withdrawn in 1894.

In 1913, two 12-pounder guns were installed at the position for training purposes and remained in use until 1922. By 1919, the armament had been expanded to four 12-pounder BL 6 cwt guns mounted on field carriages. The 1925 Air Defence Committee had identified the site as suitable for a four-gun heavy anti-aircraft (HAA) battery, although no such installation was ultimately completed. Nevertheless, in 1940 part of the position was temporarily occupied by one of the 3.7-inch anti-aircraft guns from Napier Battery.

With no permanent guns remaining at Engineer Battery, the site was subsequently adapted as a defensive nodal point against amphibious landings along the South Mole sector. This configuration comprised two machine-gun positions on the upper section of the battery, sited behind concrete embrasures.

On the right flank, the original musketry wall was encased within a concrete casemate, in which two further heavy machine-gun embrasures were formed by adapting the earlier musketry loopholes. Four raised concrete pedestals with central fixing slots provided mounting points for Vickers medium machine guns on pedestal mountings. An iron ladder fixed to the wall at the end of the pillbox led to a walled enclosure, which likely incorporated a beach light to illuminate the pebble shoreline within the arc of fire of these positions.

A third firing position at the base of the wall provided flanking fire along the beach beneath the curtain wall leading towards Alexandria Battery. The expedient nature of this wartime adaptation is further evidenced by a defensive wall constructed from tins filled with cement, a feature later removed in the early 1990s.

Engineer Battery WWII constructions, tin wall encased in concrete (left) and machine-gun positions (right).

Vickers heavy-machine gun embrasures, two on the musketry wall encased within a pillbox structure and one embedded near the foreshore.

Bunker interior and exit to beach light.

Bunker interior showing one of the embrasures.

Left embrasure and vickers machine-gun mounting points.

Right embrasure and vickers machine-gun mounting points.

Vickers machine-gun mounting points detail.

View of pebble beach to Alexandria Battery and the New Mole from casemated embrasure.