Northumberland “D” Type
This variant is only found in Northumberland and 17 examples are known to exist. The name comes from the shape of the pillbox. It superficially resembles a Type 24 in that it is an irregular hexagon with three front faces and a long back wall, but it differs from a Type 24 by having side walls that are short and parallel rather than angled backwards, the side walls do not have embrasures either but the long back wall does.
The three front faces are angled at 45 degrees to each other and are approximately 2m long with a centrally placed embrasure. The sidewalls are 1.5m long and the rear wall is 4.5m long with a central door and an embrasure on either side of the door.