The Stockport Viaduct was designed by the civil engineer George Watson Buck on behalf of the recently formed Manchester and Birmingham Railway company. During 1839, work commenced on the structure’s construction; consuming around 11,000,000 bricks, it was completed during 1840. The viaduct is 33.85 metres (111.1 ft) high. At the time of its construction, it was the largest viaduct in the world, and it represents a major feat of Victorian engineering and a key pioneering structure of the railway age. The Stockport Viaduct is currently recognised as a Grade II* listed structure, and remains one of the world's biggest brick structures.
During the late 1880s, the Stockport Viaduct was expanded to accommodate four tracks across its deck instead of two. During the 1960s, overhead catenary lines were installed across the structure as a part of a wider electrification scheme conducted by the nationalised railway operator British Rail, allowing electric traction to traverse the structure. During the second half of the twentieth century, the M60 motorway, which circles the city, was built, passing through two of the viaduct's arches between Junction 1 (A5145 road) and Junction 27 (Portwood Roundabout). The Stockport Viaduct has been subject to multiple restoration programmes.
Following the launch and success of the first intercity railway, the Liverpool and Manchester Railway, during 1830, there was considerable enthusiasm in the development of other routes between the major cities across Britain. The establishment of the Grand Junction Railway company, which sought to build a railway between the cities of Liverpool and Birmingham came early on; it soon held ambitions to establish a railway between the city of Manchester and the strategic railway junction of Crewe; during 1837, the venture was given royal assent by Parliament.
Perhaps the most prominent structure along the approved route was the Stockport Viaduct, built to cross over the River Mersey and the surrounding valley. It was designed by the civil engineer and accomplished bridge builder George Watson Buck of the recently-formed Manchester and Birmingham Railway company; Buck also worked closely with the architect John Lowe to produce the viaduct’s design. The envisioned path for the structure was already partially occupied by the engine house of the 1831 Wear Mill; its presence was addressed by designing the viaduct to cross directly over it, placing piers at either side of the engine house. In common with Stockport railway station, the viaduct was also historically referred to as Edgeley Viaduct.
Structurally, the Stockport Viaduct possesses a peak height of 33.8 meters above the bed of the River Mersey; it has a length of 546.2 meters and, originally, a width of 9.4 meters. It comprises 22 semi-circular arches, each having a span of 19.2 meters and flanked by pair of abutment arches, possessing a 5.5 meter span, on either side. The arch rings have a thickness of 900mm. Both the arches and spandrels are composed of red brick set in lime mortar, complete with ashlar spring courses. There are 2.2 meter-high parapets located at each side of the viaduct; the distance between the crowns of the arches and the top of the parapets is 3.6 meters.