Box Tunnel East Portal (MLN19912)

MATERIALS: surviving original fabric is Bath stone ashlar; repairs and alterations are mainly in engineering brick.

DESCRIPTION: Bath stone ashlar facade with plain projecting band as a parapet, and projecting piers at either side. These have banded, vermiculated rustication, and disappear into the steep sides of the cutting. The lower parts have been remade in engineering brick (without vermiculation). The tunnel mouth is very tall, with a semi-circular arch of 30ft (9m) span. The top half of the arch has voussoirs and a keystone with vermiculated rustication. As built, the voussoirs continued to the ground. Probably c. 1938, however, the remaining voussoirs down to the springing line were remade in engineering brick (without vermiculation) and below that replaced with plain engineering brick to the ground. Within the arch and flush with it is a second, lower, arch of engineering brick, again of c. 1938, plain and semi-circular. About 10m inside the tunnel is another arch, lower still, also of engineering brick. This one is segmental and there is a window or other type of opening in the face above it.

On the north (Up) side of the portal, a later raked retaining wall in red/purple brick abuts the north pier and steps down as stairs to the east, parallel to the tracks, with a banded Bath stone ashlar pier near the east end. The steps, which have modern steel railings, come down between the tracks and the former entrance to the quarry / ammunition depot tunnel siding to the north. This tunnel entrance is c. 10m east of the main portal, appears to have a reinforced concrete portal, rectangular and aligned at an angle.

A raked, rubble retaining wall (with angle quoins) rises up behind the quarry siding portal with a face to the steps. The walls joins north of the portal to another tall raked retaining which extends east as the north (Up) side of the cutting, probably of brick and probably constructed in the C19 to create room for the quarry siding. On the south (Down) side, the 1841 portal abuts a raked, rubble-lined cutting wall, rising with a step to approximately two-thirds of its height.