Clifton Suspension Bridge

Clifton Suspension Bridge

Clifton Suspension Bridge is a suspension bridge spanning the Avon Gorge, supported on two large abutments on the Clifton (east) and Leigh Woods (west) sides. The abutments are faced with red sandstone ashlar, with the west abutment built into the sloping bank and the smaller east abutment founded on the St Vincent's Rocks cliff top. The west abutment contains 12 vaulted rubble-stone chambers over two tiers, each chamber around 11 metres high, linked by narrow shafts and tunnels.

The bridge towers are square in plan and supported by the abutments. The east tower is one metre taller than the west at 27.1 metres. Both towers are constructed of Pennant sandstone rubble with ashlar caps and cornices and limestone dressings. Each is battered on the north and south sides up to the segmental arch above the roadway. The east tower has narrow pointed-arch openings on these elevations, whereas the west does not. Above the segmental arch, a parabolic arch rises to below the land chains. The tower caps have deep coved cornices. The west tower cap carries the Latin inscription SUSPENSA VIX VIA FIT ('a suspended way made with difficulty'). The east tower cap bears the inscription COMMENCED 1836 / ISAMBARD KINGDOM BRUNEL F.R.S. ENGINEER / COMPLETED 1864 / JOHN HAWKSHAW F.R.S. WILLIAM HENRY BARLOW F.R.S. ENGINEERS / COCHRANE GROVE & CO CONTRACTORS.

Each cap contains two cast-iron saddles to which the chains are attached, mounted on rollers to provide flexibility of movement between the land and central span chains. The land chains are anchored into the ground on either side of the Gorge across corresponding land saddles. The triple chains connect to and support the deck with 162 suspension rods, each 2.4 metres apart and varying in length. The six chains comprise 4,200 links across the entire span of the bridge between the anchorages. The anchorages enter an inclined tunnel at each end, locked by iron wedges behind cast iron anchor plates bolted to the rock.

The deck is constructed of iron with longitudinal girders connected to the chains by suspension rods, cross girders with diagonal ties, and parallel footway parapets on the outside of the main structure. The parapets have wrought iron lattice girders which provide additional rigidity. The road itself is of Douglas fir sleepers covered with planking and asphalt. The span between the towers is 214 metres (412 metres between the anchorages) and rises 74.7 metres above high water, as Brunel intended. Recent analysis of the structure has proved that Brunel's design is close to the ideal.

The base of each tower is surrounded by 1.2-metre-high coped, coursed rubble sandstone parapet walls with ashlar piers. The walls extend beyond the west tower along the roadway for approximately 46 metres on the north side and 91 metres on the south.

At the west end of the bridge, the road is flanked by two single-storey toll houses located at the end of the land chains. The battered walls are constructed of coursed rubble sandstone with a sandstone ashlar plinth, quoins and dressings, with a flat roof with an overhanging moulded sandstone ashlar cornice. Inner elevations have a single attached sandstone pier. Each toll house has a single door on the west elevation and a window on the outer elevations, set in deep flat-section moulded architraves.