C - D test-stands and support structures, Former Royal Ordnance Establishment, Westcott

The former Royal Ordnance Establishment at Westcott includes a pair of test stands, C and D, along with associated support structures, all dating to the mid-20th century. The complex also incorporates a fuel management system and earth traverses for protection. Building 209, a contemporary support workshop, sits to the south of the stands, and Building 360 lies between them.

C Test Stand (also known as Building 208) is the less imposing of the two stands and retains a greater degree of original fabric. It features a pair of mirror-image firing bays to the north, with original ceiling gantries and direct observation windows. Brick control and observation rooms are situated on either side, and storage chambers for oxidants and fuel are located behind (to the south), mirroring the design of earlier B stands. This stand represents the most original example of the pre-November 1947 design among the four early test stands (A, B, C, and D) at Westcott. A later periscope has been inserted through one observation window in each firing chamber, and the control panels are of a later date, from the 1960s to 1980s. Some fittings have been removed. Earth traverses are present to the north, along with drains and tanks to both the north and south.

D Test Stand (also known as Building 207), originally the pair of A stand, remains in use for testing and has a more recent superstructure, including heavy chain mail and torpedo netting to the north. Unlike the C stand, there are gaps between the control rooms and the firing bays, a feature also found on the original A stand. Ceiling gantries and other fittings have been removed to facilitate contemporary use. Circular periscope hatches remain. Tanks and run-off channels are located to the north and south, though some to the north have been backfilled. An earth traverse is present to the north. As with the A stand, oxidants were stored to the sides and fuel to the rear. The control rooms, to the west and east, are primarily of reinforced concrete, with a brick shield wall to the east. The control room doors are substantial, likely installed following an incident in November 1947, and include additional square escape hatches.

The main and original workshop for the test stands is Building 209, a prefabricated structure with a pitched corrugated roof, metal multi-paned casements, and a flat-roofed concrete porch at the south-east corner. Building 360, located between the two stands, is a small, flat-roofed structure built in red brick English bond, featuring metal-framed casements, concrete cills and heads, and an observation window to the north.