Southern gatehouse to the Blackwall Tunnel

Southern Gatehouse to the Blackwall Tunnel

This tunnel gatehouse was opened in 1897 for the London County Council to designs by Thomas Blashill, the Council's Superintending Architect. It stands 255 metres south of the southern portal to the Blackwall Tunnel, positioned across the northbound carriageway of the tunnel approach road.

The building is constructed of yellow and red sandstone with slate roofs topped by lead-covered cupolas and cast-iron water goods. It is rectangular in plan, oriented east-west, and rises to two storeys plus an attic level.

The gatehouse is designed in an Arts and Crafts Scots-Baronial style, featuring irregular banding of red and yellow sandstone with a moulded stone eaves cornice. The principal feature is a large round arch with moulded detail framing the carriageway; the vault of the arch is lined with glazed terracotta tiles set between stone ribs. Windows are timber casements in square-headed openings with moulded surrounds and mullions. The south elevation displays a row of seven windows above the date '1897' and the inscription 'Blackwall Tunnel' in relief, flanked by shields bearing the arms of Surrey and Kent. At each of the four corners stand engaged towers with square-headed lancet windows, topped by distinctive octagonal turrets with ogee cupolas and buttoned spike finials. Between the turrets on the east and west elevations are broad chimneys with indented caps. The steeply pitched, near-pyramidal roof has small hipped dormers on the north slope and larger dormers with triple timber casements on the south slope. A door on the upper level of the west elevation has been enlarged from an original window and is accessed via a later twentieth-century metal fire-escape and ladder.

On the east wall of the archway is a bronze dedication plaque by Singer & Son of Frome. The inscription recording the tunnel's opening is flanked by bare-breasted female figures, with a bearded river god's head at the top. Below the text is a depiction of a section of the tunnel with construction work in progress.

The ground floor consists of the archway, with access to the upper floors via an internal stair from a door in the east wall. The first floor above contains four rooms: a scullery and living room on the east side of the building off a central corridor, with two bedrooms on the west side. The attic floor includes a cistern room and third bedroom on the east side, with the remainder originally forming a single storage space, now partitioned into two rooms.

A timber post and rail stair provides access to the first floor. Original four-panel doors, architraves and skirting survive on the first floor. Concrete arches give access to the four corner turrets. A brick chimney breast remains in the original living room, though its surround has been lost. Some lathe and plaster ceilings have been lost, exposing the joists beneath. The attic floor is lined with matchboard panelling with ceiling panels set in a timber frame; some panels have been lost in places, revealing the boarded roof structure.

Running north from the gatehouse on either side of the carriageway, with a narrow section flanking the gatehouse itself, are walls faced with concrete panels from the late 1960s. These later walls are excluded from the listing.