Bascule Bridge(also listed in Queensferry rec no 84433)

The Bascule Bridge is a bridge built with riveted I-section steel girders. It features a slightly humped deck with an opening joint at the center, supported by two pairs of large circular piers that are rendered over iron or steel. Each pair of piers is separated by lateral braces, and the low abutments are made of concrete blocks.

The superstructure includes vertical and raked steel posts and horizontal steel beams, with lateral braces at the top forming a lighter lattice work. The opening mechanisms, positioned over the two sets of piers, consist of pairs of curved racks that swing down onto pegged beams to lift the cantilevered road sections. Above each pair of racks, there are large angled steel plates within a high vertical superstructure of lattice steelwork, with girders curving down to connect to the main superstructure.

In front of the steel plates, there is a frame containing the gearing mechanism, which includes small gear wheels, although the original power source is no longer present. The road is flanked by footways that are outside the main superstructure and supported underneath by curved beams. These footways pass under original steel archways connected to the opening mechanisms and are equipped with plain steel railings. Many of the steel girders are marked with 'Cargo Fleet England', while a few are labeled 'Lanarkshire'.