Eight cantilevered pillboxes at the former RAF Oakington

MATERIALS: Reinforced concrete and London Brick Company Phorpres bricks.

PLAN: Circular and partially subterranean, the structure was designed to be covered with earthworks to prevent detection from the ground and air.

EXTERIOR: The pillboxes are approximately 5.5m in diameter and have a reinforced concrete, disc-shaped roof supported at its centre by a substantial, brick cruciform-shaped, anti-ricochet wall. Around the perimeter is a brick and concrete composite, subterranean curtain wall that finishes approximately 30cms below the outside lip of the roof, thus giving an open observation and firing slit around the entire structure. The gun openings of nos. 446 and 462 have been wholly or partiallly infilled with brick and part of the curtain wall of no. 454 has been removed and shored with corrugated metal sheets. The traversed, brick entrances are stepped to the interior.

INTERIOR: The central anti-ricochet wall supports the roof, allowing easy access around the circumference. A 5cm tubular steel rail is fixed to the inside of the curtain wall around which machine-gun turnbulls could slide and be locked in any position. Most of the Oakington pillboxes retain the rail. The turnbull survives in no. 445 which also has a single loop hole for a Boys anti-tank weapon aimed at the railway and ammunition locker recesses built into the curtain wall.

SUBSIDIARY FEATURE: Linked to no. 445 is a partially below-ground, brick and concrete, detached, trenched air-raid shelter. The shelter has a concrete entrance to the north and a central concrete opening. To the south a trench leads into the pillbox. The interior of the shelter has two partition walls, presumably for ablutions.