Summary
The Gatehouse at Bond's Mill, Stonehouse is a two-storey non-standard pillbox of 1940 date. It has been adapted to form two modern office units.
Reasons for Designation
The Gatehouse at Bond's Mill, Stonehouse is designated at Grade II for the following principal reasons:
* Rarity: the pillbox is a rare example of a Type 24 pillbox constructed to a two-storey height with rooftop gun emplacement. There are few other known examples.
* Intactness: the pillbox is relatively unaltered and complete, and its original use is plainly legible.
* Representative Value: the pillbox illustrates a key point on a former stop line, defending road and canal, and two armaments factories.
History
This pillbox was constructed as part of a national defence programme in response to the threat of German invasion in 1940. Coastal defences (batteries, mines and barbed wire) were strengthened, and defensive lines stretching inland were created in order to slow down the progress of an invading force. The defensive lines, or stop lines, provided final defensive positions for London and the main industrial areas in England. General Headquarters (GHQ) Stop Line: Green (also known as The Bristol Outer Defence Line), was constructed in 1940 and protected Bristol and the port of Avonmouth from attacks from the east. Stop Line Green looped around Bristol and Bath from Burnham-on-Sea in Somerset to Newnham in Gloucestershire, a distance of 90 miles with 18 miles of anti-tank ditch, approximately 370 pillboxes and 250 road blocks. The Stroudwater Navigation marks the most northerly point of the stop line and The Gatehouse is one of a number of pillboxes that lines the waterway.
The Gatehouse was constructed in 1940 along with 15 other pillboxes along the Stroudwater Navigation. It stands on the north bank of the canal, opposite Bond's Mill, which was the site of a key wartime "shadow" factory: Sperry's Gyroscope Company was established to supplement an existing operation at Brentford, Middlesex to avoid air attacks, and manufactured instruments for the aircraft industry. Another factory was located nearby, operating for the Hoffmann Manufacturing Company. Some time after the war the pillbox was adapted to a gatehouse for the mill and it contains the controls to operate the neighbouring bridge across the canal. The bridge was replaced in 1994 with the first composite plastic lift bridge to be built in the world for vehicular traffic. A number of modifications to The Gatehouse, including the insertion of new openings, took place in the C20, perhaps at the time it became a gatehouse. In the C21 it is in office use, and has been refurbished.
Details
MATERIALS: the ground floor level is constructed of reinforced concrete, the upper storey of red brick.
PLAN: it is based on the Type-24 pillbox: octagonal on plan with a projecting porch to the south.
EXTERIOR: by the porch, a steel stairway with timber steps leads to a first floor doorway, which carries a steel grille. At each corner, the bricks are uncut and project in a cogged pattern. A fixed steel ladder in the upper storey room leads to a roof hatchway. There is a red brick enclosure on the flat concrete roof, a former gun emplacement with evidence of removed fittings. The roof is lined by steel railings. There are three original first floor embrasures with concrete lintels, and in addition eight later window openings have been inserted, the upper ones with concrete architraves. The larger openings have clay tile cills. The windows have white powder coated crittal-style frames. The exterior also carries a good deal of signage and other furniture including CCTV cameras.
INTERIOR: the floors, ceilings and walls have modern finishes, and there are no historic fittings. The windows have internal steel bars.
