The Forth Bridge

The Forth Bridge is a significant cantilever railway bridge designed by Sir John Fowler and Sir Benjamin Baker, constructed between 1883 and 1890, with the design and tendering process starting in 1882. It spans 2.5 kilometres and is made of painted steel, crossing the Firth of Forth and linking the counties of Edinburgh and Fife.

The bridge features three giant, cross-braced steel towers, each counterbalancing two arms on either side to create two full cantilevered spans, each measuring 521 metres long, along with a 107-metre suspended span truss at the centre and two half outer spans. Each tower is supported by four circular-plan granite and concrete piers. The southern piers are located on the sea-bed, the central piers sit on a shelf of rock beside Inchgarvie in Dalmeny Parish, and the northern piers are positioned on a promontory at North Queensferry.

The superstructure is accompanied by approach viaducts that are elevated 45 metres above water level, supported by tapering, rectangular-plan masonry piers. There are five piers to the north with three masonry arches connecting to the promontory at North Queensferry, and ten piers to the south with four masonry arches linking to the promontory at South Queensferry. Trains enter the cantilever superstructure through round-arch masonry portals located at the innermost piers.

Additionally, there is a remnant of a brick pier from a design by Thomas Bouch from 1879 at Inchgarvie rock, topped with an early 20th-century cast-iron leading light featuring a sectional lantern, a bracketed gallery, and diamond-paned glazing.