Bascule Bridge(also listed in Queensferry rec no 84433)

Cadw's description

Location

The bridge carries the B5441 across the River Dee, linking Garden City with Queensferry.

History

Constructed in 1924-6 by Sir Basil Mott and the Flintshire County Surveyor and Bridge Master, R G Whitley. It replaced the Victoria Jubilee Bridge, completed only in 1899, which did not have the size or strength to carry the volume of traffic. The snecked stone abutments of the Victorian bridge survive immediately to the W.

Exterior

Bascule bridge constructed of riveted I-section steel girders, the slightly humped deck with opening joint to centre, supported on 2 pairs of large circular piers, rendered over iron or steel, each pair separated by lateral braces; low abutments built of concrete blocks. The superstructure is of vertical and raked steel posts, horizontal steel beams, with lateral braces across top of lighter lattice work. The opening mechanisms, located over the 2 sets of piers, consist of pairs of curved racks, which swung down onto pegged beams pulling up the cantilevered road sections; attached above each pair of racks is a large angled steel plate within a high vertical superstructure of lattice steelwork, girders curving down to join the top of the main superstructure. A frame containing the gearing mechanism, including small gear wheels, is located in front of the steel plates, but the original power source has gone. The road is flanked by footways outside the main superstructure, supported underneath by curved beams; the footways pass under original steel archways which are joined to the opening mechanisms, and they have plain steel railings. Many of the steel girders are labelled 'Cargo Fleet England', a few marked 'Lanarkshire'.

Reason for designation

Listed for its technical interest as a rare surviving example of a bascule bridge, retaining its architectural character and detail.