In April I spent a pleasant day at Lavenham. So a few posts to follow on this visit starting with this 6 pdr anti-tank gun pillbox at Slough Farm. It was sited to control the approach to, as well a crossing over, the Command Line. The anti-tank obstacle was the railway line, with deep cuttings in places, as well as sections of anti-tank ditch where the railway line did not provide an adequate obstacle.
It is probably to design C.R.E 1116, one of three new designs of pillboxes to be used on the Command Line. It is obviously based on the Type 28a but was designed to house a static 6 pounder gun and not the 2 pounder gun. There is a holdfast for the gun and the main embrasure is narrower than that on a Type 28a designed for the 2 pounder. The other two differences are the low level protected entrance which is a common feature on pillboxes on the Command Line and a lack of internal Anti-Ricochet wall separating the infantry light machine gun embrasures from the gun embrasure.
According to the official documents, the serial number of this pillbox was "CA3", but the white stencil on the holdfast clearly has an "B" as well as a "3" marked. The gun was never mounted and the main embrasure was blocked up and two small rifle embrasures added instead, which both are angled.
Image 1: Holdfast and embrasure for 6 pdr gun and embrasure for light machine gun. Main embrasure has been blocked up and two rifle embrasures added.
Image 2: Holdfast with white stencil showing "B" and a "3".
Image 3: Main embrasure from the outside, now blocked up and two rifle embrasures added.
Image 4: Close up of the rifle embrasures, note how they have been strongly angled.
Image 5: The approach to the Command Line this pillbox controlled (the pillbox is located on the left hand side of the bridge).