In Italy the Germans have been using a mobile steel pillbox, nicknamed the "Armored Crab," which made its first appearance on the Russian front in 1943. This pillbox (see figure) is mounted in an inverted position on wheels, and usually is hauled by tractor to a designated site, where it is overturned into a prepared cavity. After this, the exposed upper half of the pillbox (which is non-rotating) is camouflaged with rocks, earth, or local vegetation.
In the front of the pillbox, there is a small embrasure for the machine gun, with an observation peephole above. When necessary, these openings are covered outside by a heavy metal shield, which can be moved either to the right or left of the embrasure by means of a lever inside the pillbox. On top of the pillbox are two collapsible periscopes, also regulated from the interior. The entrance to the pillbox is a small door in the rear; this is locked from the inside by means of two brackets.
The machine gun is mounted on a single bracket mounting which allows a free horizontal traverse on a semicircular grooved slide. The field of fire is 60 degrees. Elevation and depression, which are limited, are accomplished by a small handle to the left of the machine gun.
Forward of the machine-gun trigger, there is a leather cover to channel off the gases from the gun and also to receive spent cartridges. Attached to the cover is a metal tube. In turn, this tube is connected to a metal box fastened to the floor. The gases are expelled by a small fan situated beside the metal box. The fan is operated by two small foot pedals, one on each side of the pillbox. Each pedal may be worked independently. Air is expelled through a slit above, and to the right of, the door. Fresh air enters through a vent in the ceiling.
Two folding seats are provided for the crew. There are two iron rungs which serve as steps to facilitate entering and leaving. Two leather straps are hung from the ceiling, near the periscope openings.
At the rear of the pillbox, and near the top, there are two holes into which steel bars may be inserted to lift the pillbox on and off its trailer. When these holes are not in use, they are closed by metal plugs.
Ammunition is stored on shelves below the machine gun, in the forward part of the pillbox. There are also two boxes for tools and spare parts for the gun. Space is provided for a field telephone.
The pillbox accommodates two men, and is armed an M.G. 42.