Traverse to former Shifting House, Lower Upnor Ordnance Depot

The traverse to the former Shifting House at the Lower Upnor Ordnance Depot was built in 1811. A traverse is a protective earthwork designed to contain any accidental explosions from the structure it shields, which in this case is the shifting house.

This earthwork is made of earth with retaining walls constructed from yellow stock brick laid in Flemish bond. The traverse has a broadly triangular shape, featuring long walls on the west and east sides and a shorter return wall to the north.

The Lower Upnor Ordnance Depot is situated north-south next to the west bank of the River Medway, just north of Upnor Castle, which was built between 1559 and 1567 and is a Grade I listed structure. The traverse, located at the southern end of the site, is immediately north of Upnor Castle and south of the Grade II* listed B magazine. The wall of the traverse slopes upward to the south, with a rising coping that encloses and retains an almost triangular earth embankment. The wall retains the north, west, and east sides of the traverse. At the time of inspection, the area was very overgrown, but the revetment wall was partially visible on all sides, indicating the presence of brickwork, which appears uniform. A square pier is located at the north-west corner where the traverse wall returns.