Summary
Block A, consisting of the sluice housing and pattern stores built in the 1940s, and offices and workshops, 1900, with the system of culverted sluices, and boundary walls and gatepiers.
Reasons for Designation
Block A: Sluice Building and Stores and the system of sluices is listed at Grade II* for the following principal reasons:
Architectural interest:
* the system of culverts and sluices built into Jessop’s dam in the 1840s survives well and was an innovative and effective response to managing water and alluvium levels in the Floating Harbour, and remains operational;
* Block A is a building of two phases 50 years apart, both of which are carefully detailed to follow the architectural conventions established for the Underfall Yard, characterised by robust, rhythmical forms in Cattybrook brick;
* Block A west remains legible as a building for storage and light industry, retaining a gantry crane and lifting frame;
* Block A east is constructed using a reinforced concrete frame, providing a fortified housing for the important equipment within, and the rooftop firewatchers’ post speaks of the threat of the Second World War.
Historic interest:
* a key component of Jessop’s Floating Harbour, and ambitious and innovative early-C19 major work of engineering that gave shape to the city centre;
* the development of the Floating Harbour enabled the City Docks to function irrespective of the tides, bolstering Bristol’s fortune in the C19, before the port at Avonmouth took precedence;
* water and alluvium management technology with associations with Jessop in its conception; with Brunel in its mid-C19 implementation, and with Docks Engineer John Girdlestone in its late-C19 refinement.
Group value:
* with the other listed buildings in the Underfall Yard, and the adjacent Avon Crescent and the Nova Scotia;
* as a key component of the Floating Harbour and part of its extensive ensemble of structures and infrastructure, including the Cumberland Basin and its junction locks.
History
When the Floating Harbour was created at the beginning of the C19, it reputedly provided Bristol with the largest area of impounded water for shipping in the world, negating the dependency of the City Docks on the tidal River Avon. The scheme of 1802 by William Jessop created a contained harbour with consistent water levels by damming the original course of the river and excavating a new course, or “New Cut”, that diverted the river around the City to the south.
The Underfall Yard has been crucial to the operation and maintenance of the harbour from the outset. It stands on reclaimed land on the original course of the river at the point that it was dammed. An overfall weir was built to manage water levels by draining into the New Cut, with the area around it becoming the Docks Company Works Yard. The larger area of land to the north had been established as a commercial shipyard by at least 1825, and was known as the Nova Scotia Yard, later the Cambria Yard.
While the original overfall enabled the harbour’s water levels to be controlled, the build-up of silt became problematic, necessitating periodic emptying and excavation. In the 1830s IK Brunel was appointed Consultant Docks Engineer, and was tasked with finding a solution. Jessop’s original design included sluices, and Brunel developed this, along with the use of drag dredgers. Culverts were built into the dam in the 1840s, with sluice gates to control the flow. The system was remodelled in the 1850s, and again in the 1890s. There are four brick-lined culverts, one of which is deeper, with an adjacent sump to encourage silt to settle before being flushed out. This arrangement remains in use, though the original cast iron sluice paddles have been replaced.
The Bristol Corporation bought the Nova Scotia Yard in 1880 in order to extend the Docks Company Works Yard, and to bring all maintenance facilities together in one place. Temporary workshop facilities on the site were replaced by a purpose-built complex of buildings to accommodate the diverse workforce, which at its peak numbered 400 and included draughtsmen, plumbers, patternmakers, blacksmiths, divers, dredgers, engineers, fitters and shipwrights. This first phase of construction was led by Docks Engineer in Chief Thomas Howard, and his successor from 1882, John Girdlestone. A second phase of development was made between 1900 and 1906 under W W Squire, when the yard was expanded and reconfigured in response to the development of the GWR Docks Railway.
The western range of Block A was constructed under Squire’s direction in around 1900 as offices and stores, replacing an earlier structure and retaining elements of its fabric. Contract drawings are signed C A Hayes, the contractor for the hydraulic engine house. The eastern range of Block A was built after the outbreak of the Second World War to house the sluices. This new structure was a three-storey, concrete-framed block, carefully detailed to match the western range, with the sluice room on the ground floor and pattern stores and workshops above. The decision to fortify the housing for the sluices signifies the importance of its continued operation, and the rooftop fire-watcher's post speaks of the threat of bombardment.
An additional set of sluices was installed adjacent to the harbour wall, providing a secondary defence in case of damage to the original sluices; machinery is housed in a small brick block. Another emergency sluice gate is located at the point of discharge into the New Cut.
Use of the docks declined in the C20 as the size of vessels increased. Buildings at the yard became surplus to the requirements of the Bristol Docks Company, and were let out. Steam-paddle boat operator P&A Campbell let a number of buildings on the yard until 1958, after which it was largely vacant, though the sluices remained operational throughout. The sluice paddles installed in 1900 have been replaced by re-castings; the first of these to be replaced is now affixed to the north elevation. The Underfall Yard Trust, created in the 1990s, has restored the building; Block A has undergone some internal reconfiguration to accommodate changing rooms, offices and workshops, and has had a new stair inserted at the junction between the east and west sides.
Details
Block A, consisting of the sluice housing and pattern stores built in the 1940s, and offices and workshops, 1900, with the system of culverted sluices, and boundary walls and gatepiers.
MATERIALS: red Cattybrook brick laid mainly in Flemish bond. A slate roof above the western range.
PLAN: the building stands on the southern boundary of the Underfall Yard, running parallel with Cumberland Road and the New Cut. It has a linear rectangular footprint.
EXTERIOR: a three-storey building of two halves: the seven-bay range to the west, dating from around 1900, and the six-bay range to the east, built in the 1940s. Elevations are formally composed and minimally adorned, with regular, evenly-spaced segmental-arched window openings with projecting brick sills to each bay. Windows have multiple lights in iron frames. The western half has a plain stepped brick cornice, and the east a plain parapet in front of the flat roof.
The principal elevation faces north onto the yard; the western (right) half is symmetrically laid-out with a central doorway, also with an arched head, and taking-in doors and a hoist bracket above. The eastern (left) half has a six windows bays, and to the right, a wide ground-floor opening with taking-in doors above. Openings on the left been altered, and a window changed to a doorway on the second floor, accessed by an external metal stair.
The southern, road-facing elevation has seven bays to the west, and six to the east, with a break in the masonry roughly half-way along, covered by a downpipe. The ground floor is blind, and there are three wide blocked openings to the sluice room. Upper floors have a window to each bay.
The east return elevation has a doorway and small window on the ground floor, and is blind above. A single-storey structure abutting the elevation has been removed.
There is a small brick fire-watcher's post on the roof of the eastern range.
INTERIOR: within the eastern range the concrete frame of the structure is exposed, and has deep cross beams to the ceilings. The sluice chamber is on the ground floor, and retains cast iron beams, transoms, saddles and slide-ways. The sluices are numbered 1 to 4, with the third set at a greater depth to scour silt. Cast iron paddles, installed in 1900, have been replaced with new castings. Upper floors are open plan; the first floor retains timber shelving units, and the second floor has been converted to provide a canteen area.
The western range is constructed with timber floors bearing onto a steel beam and column system designed for heavy loading. The ground floor has been reconfigured to provide changing rooms and toilets, and floors above are largely open-plan. The second floor is open to the roof, which is formed from a series of king post trusses with timber matchboarding. There is an overhead travelling gantry crane by Wadsworth of Bolton. A timber open well stair has lifting-frame mounted above.
SUBSIDIARY FEATURES: the four brick-lined sluice conduits run from the harbour wall to the north, beneath the sluice house, and out through the retaining wall to the New Cut, to the south.
East of the building the yard is enclosed by a length of brick wall. There is a wide entrance gateway with stone-capped brick piers, and a pedestrian doorway with an arched head.
