Shellproof Gun-houses for Anti-tank and Field Guns – Type 28
Although pillboxes in the group Type 28 follow similar guidelines, each individual pillbox is different. This diversity can be seen by differences in wall thickness, the amount of rifle loops, the materials used for construction, camouflage and other modifications such as shutters and blast walls. The construction of pillboxes required a casing to allow the concrete to be poured and dried in shape, this process is known as shuttering. When built the concrete may be shuttered with wooden boards, corrugated iron sheets or bricks. When shuttered with brick, the shuttering was often left on the outside of the concrete casing, as it would have been inefficient to remove the mould. This added an extra layer to the pillboxes created in this way, often making them appear as made from bricks alone. It was realised that the pillboxes would be required to withstand artillery and dive-bomber attacks and so many pillboxes were made shellproof by increasing the thickness of the walls.
The Type 28 is usually a rectangular shaped shellproof pillbox designed as a gun-house for anti-tank weaponry. The Type 28 usually consisted of a large embrasure to the front for an anti-tank weapon and several smaller loopholes suitable for rifles and light machine guns to the sides and rear of the pillbox. These pillboxes would have been equipped with a single two or six pounder anti-tank gun. Type 28 pillboxes would usually be placed as part of a defensive network to help compensate for the smaller field of fire. The Type 28s flaw was that there were no forward facing small arms loopholes and a quite restricted field of fire to the sides, leaving the Type 28 vulnerable to enemy infantry attacks. To counter this, modifications were made to the Type 28 design to help produce the Type 28a.
The Type 28a is an evolution of the Type 28, designed to allow increased firepower by adding an extra chamber for infantry loopholes to be placed. The Type 28a is a fairly large shellproof pillbox designed as a gun-house to accommodate anti-tank weaponry, and is usually rectangular in shape. The 28a was a standard emplacement for a two pounder anti-tank gun and was built on many defence lines. Variations could often include extra blast walls and different configurations of loopholes and weapon mountings. When left in position the shield of the anti-tank gun would cover most of the embrasure, protecting the gun crew but also limiting the rotation of the gun from 60 to 70 degrees. Some 28a pillboxes were built with two larger loopholes to allow a greater field of fire for the anti-tank guns, these examples also contain a hollow in the centre to allow for the guns pivot and would also likely have an anti-ricochet wall which may have been reinforced with sandbags to protect the pillbox’s occupants. There would also be recesses in the floor to allow the supporting legs of an anti-tank gun to be positioned to reduce the recoil of the weapon. The entrance to the pillbox would be fairly wide to allow the mobile anti-tank guns to be wheeled in or out. There is little evidence of attempts to cover the large entrance with doors and so when in action it is likely that sandbags would help provide the necessary defensive screen.
These types of pillboxes would often be positioned to fire along fixed lines to help increase the effectiveness of other defensive features such as anti-tank ditches or dragons teeth. The specific positioning of the Type 28s meant that the limited ability of the anti-tank weapon to alter its field of fire would not cause a disadvantage as the pillbox would be covering a specific area, for example facing the length of a bridge. The Types 28 and 28a were fairly common along the Surrey GHQ Line, there are several examples still surviving. According to the Defence of Britain Project there are still 232 Type 28a and 149 Type 28 pillboxes remaining throughout Britain.
Surrey’s pillboxes are included in the county’s Historic Environment Record (HER), click the link to see more information.