Armoury

You can't easily describe pillboxes without talking about their armament. It's all very well standing in a pillbox, putting your eye up close to an embrasure and pronouncing that as you can see a particular piece of ground, nobody could possibly hope to survive under fire there.

Weapons such as the Vickers gun (right), were mounted on tripods or Turnbull Mountings that provided a limit to the elevation/depression and arc of fire, so your line of sight does not necessarily reflect that of the weapon; by leaning forward you can see more ground in all directions that the gun couldn't cover. By standing back in the pillbox you get a better idea of what the gunner could see.

What use is this technique? Well, if there are blindspots in a pillbox's coverage of ground, there was probably some means to defend them. Is there another pillbox that can cover the dead ground? Was there perhaps a minefield or other obstacle sited there instead, or an infantry slit trench?

Does the design of the embrasure or remains of a weapon mounting provide a clue as to which weapon(s) they were intended for?

Basic knowledge of the main infantry small arms in use in the British Army in 1940 is therefore helpful, as pillboxes were designed with these weapons in mind.

Fixed Lines

Pillboxes that were included within a unit's defence scheme had their own fire plan; i.e. the area the pillbox was to defend. In daylight, a gunner could see to shoot at targets within his killing zone, but in darkness or in conditions of fog or thick smoke, he would be unable to shoot accurately and be in danger of hitting neighbouring pillboxes or slit trenches.

Therefore, fixed lines were important. A machine gun set to fire on a fixed line meant exactly that; held firm on its tripod or other mounting, it would fire along a set line where it was known it would hit a specific target area. For example, a gap in a barbed wire obstacle could be covered by setting a mounted gun to cover it in daylight; if the enemy tried to rush through the gap under cover of darkness or smoke, the gunner would only need to press the trigger and keep the gun working to know that he was shooting anyone trying to penetrate the defences.

A machine gun mounting permits the gun to move in two planes; a lateral arc (side-to-side) and elevation/depression (up and down), controlled by screw-thread mechanisms that permit precise adjustment. A graduated scale of some description allows the lateral arc to be read by the gunner. A clamping mechanism allows the gun to be fixed at a precise elevation and pointing in a precise direction.

Below is a fixed line fire plan for a Bren Gun:

Bren Gun Defensive Fire Program

The original fixed line will be as near obstacle as possible, but not less than 2° from the next pillbox.

Programme

Fire ONE magazine RAPID in Fixed Line
Reduce elevation by ONE rotation of the Elevating Screw, and fire ONE magazine RAPID
Switch 5 degrees seawards, and fire ONE magazine NORMAL rate
Increase elevation by ONE rotation of the Elevating Screw, and fire ONE magazine at NORMAL rate
Switch 5 degrees landwards, check up original Fixed Line
Repeat ONCE

Defensive fire will be brought down at night as follows:

On the "General defensive fire signal" i.e., a "Golden Rain" rocket being sent up in the Company sector
On the sentry or N.C.O. in charge of the pillbox being convinced that a landing is being attempted by the sounds he hears, or by observation

This programme will be repeated only if the "defensive fire signal" is repeated, or if the sentry or N.C.O. in charge of the pillbox is convinced that a landing is still being attempted.

Hibbs, Peter Armoury (2012) Available at: http://www.pillbox.org.uk/armoury/index.asp? Accessed: 05 February 2012

The information on this website is intended solely to describe the ongoing research activity of The Defence of East Sussex Project; it is not comprehensive or properly presented. It is therefore NOT suitable as a basis for producing derivative works or surveys!