Pillbox Gun Mounts

Turnbull Mounts

Turnbull mounts were not exclusively used for mounting Vickers machine-guns but Brens, Lewis, water cooled Brownings and Hotchkiss MGs could all be used, there was even a request from Bovington if a gun bar could be designed for there Besa Machine guns. I suspect in fact that Bren guns were the most common weapon mounted (simply because an infantry division held 1,262 Bren guns against only 40 Vickers MMGs) even then I suppose they were only fitted when on alert. Turnbull mounts were issued from 1941 onwards, so those found in C1940 pillboxes were fitted later. Each mount need 4′ 9″ of space between the loophole and the back (baffle) wall to allow the gunner room to position himself behind the mount.


The mounting consisted of three parts:

 The ‘Loophole’ Frame

The frame is a rectangular component made of angle iron and providing upper and lower pivot bearings for the cradle. The frame can be built into loopholes of pillboxes, built into sandbag emplacements by being attached to transverse iron or wooden members by bolts or wire, or fitted to holes knocked in walls, use being made of uprights supported by spurs.

The frame is stamped or stencilled on the inner side “top”, and “this side towards firer”.

The frame is provided with a traversing arc and traversing stops.

 The Cradle

The cradle is the component which pivots at the forward end upon the upper and lower bearing pivots of the frame. The elevating gear is incorporated in the cradle, and forward and rear mounting points are provided on to which the gun bars which carry the various guns are mounted.

The rear mounting point is on the top of the elevating gear.

The cradle is mounted and dismounted from the pivot bearings of the frame, by being lifted above them and lowered gently on to them.

On the top of the cradle is a traversing clamp which acts in conjunction with the traversing arc of the loophole frame.

Gun bars for the following weapons are provided:

 (a) Vickers Machine Gun .303-in. and .30-in. models

 (b) Bren Gun.

 (c) Lewis Gun with radiator casing.

 (There is no Gun Bar for the stripped Lewis Gun, a sandbag as a rest in the loophole is all that is essential for this weapon.)

 (d) U.S. .30 Browning. Medium water cooled Machine gun

 Each Gun Bar is provided with mounting points, fixing pins and securing bands to suit the particular weapon it is designed to carry.

Each Turnbull mount (also known as Mounting Machine Gun Loophole) had a traverse of 90 degrees, elevation of 11 1/2 degrees and depression of 12 degrees

A complete set of equipment consisted of one cradle, one Vickers Gun Bar and one Bren bar. Other Bars were issued as required. loophole frames were produced at a rate of two to each equipment set.

A number of mounts in my area (Norfolk Suffolk border) have steal tubing and a recess built into the embrasure below the Turnbull Mount presumably to hold the condenser tube of the Vickers MMG.

Hope this may be of interest to PSG members.

Paddy Rushmere.

Oakington Gun Mount

Photograph by Eric Burke

This mount is associated with the `Mushroom `Pillbox design.


The idea was to fix a machine-gun, probably something like a .50 calibre, on to the mount which then moves on the circular scaffolding type metal pole fitted around the interior of the structure.

See the Mushroom Pillbox Page for more photos.

Bren Gun Mounting

Visit Us On TwitterVisit Us On Facebook

Join Online

We welcome new members to the PSG. We currently have over 300 members in six countries. Members receive the journal Loopholes three times a year which details recent finds and sites of particular interest.
Clicking the Subscribe button will take you to PayPal. Subscriptions will auto- renew until cancelled.
UK Membership - £11.00 - PayPal

Overseas Membership - £16.00 - PayPal

For more details about PSG, membership, Pillboxes or Defence Structure related topics contact our Co-ordinator Roger Thomas


Defence Structures and sites of all types both above and below ground can be very dangerous. Serious injury or even death can arise from unauthorised entry into such sites and structures. Join a responsible club, group or society who can arrange official visits. The Pillbox Study Group accepts no responsibility for any damages or injuries caused by ignoring this advice. The PSG does not encourage members to undertake the ad hoc clearance of vegetation from pillboxes, as it can expose them to physical damage and inappropriate use, it may also contravene a variety of statutory regulations including, listed buildings and SSSI designations. Vegetation clearance should only ever be undertaken as part of a formal arrangement, having sought and obtained permission from the land owner and other necessary authorities. Damaging a listed or scheduled monument can be considered as a Heritage Crime.

Top 100 Military Sites

Social Network Widget by Acurax Small Business Website Designers