The MSJ&AR line is notable for having operated with three different systems of electrification within a period of about 60 years. The fast, frequent service resulting from the introduction of the first generation of electric trains in 1931 was a significant contributor to suburban development in the Stretford, Sale and Altrincham districts, south-west of Manchester.
The southern part of the MSJ&AR’s route has been part of the Manchester Metrolink light rail system since 1992. The northern section between Manchester Piccadilly and Deansgate stations is now an intensively-used section of the National Rail network, used by trains running north and west of Manchester.
Manchester’s London Road railway station (today’s Piccadilly) was opened on 8 May 1842. London Road was the terminus for two trunk lines approaching the city from the south and east - the Manchester and Birmingham Railway from Stockport and Crewe, and the Sheffield, Ashton-under-Lyne and Manchester Railway, which at that point ran only as far as Godley, but would eventually be extended to Sheffield via the Woodhead route.
Even in the early days, it was clear that the dead-end terminal at London Road would need to be connected to the other railway lines serving Manchester. The Manchester & Birmingham and the Sheffield, Ashton-under-Lyne & Manchester companies proposed an extension of their lines which would skirt the southern part of Manchester city centre on a 2.4 km (1½ mile) viaduct, and join the Liverpool and Manchester Railway at Ordsall Lane in Salford. This was promoted as the South Junction Line. A branch line was also proposed, leaving the South Junction line at Castlefield (west of today’s Deansgate station) and following the Bridgewater Canal to Altrincham. The Manchester South Junction and Altrincham Railway Act received Royal Assent on 21 July 1845.
The engineers were: Joseph Locke, George W. Buck and William Baker. Contracts were let on 23 Oct 1845 to David Bellhouse (South Junction) and John Brogden (Altrincham Branch). After some haggling over the price of land etc., a report of actual construction was presented on 30 Oct 1846. However work was then suspended as the company had run out of money. A public offering of five year bonds at 5% per annum raised only £50,000 so a further Act of Parliament (22 Jul 1848) was required to increase the capital by £250,000 to £650,000. The two owning companies each provided half of this amount. On 20 Jan 1849 a viaduct near Oxford Road collapsed as the scaffolding was removed. Three men died and two were injured. On the 25th the two adjacent arches failed without injury. The accepted reason was slow setting of mortar in wet weather.