First Elevated Train: London and Greenwich Railway
The earliest elevated railway was the London and Greenwich Railway on a brick viaduct of 878 arches, built between 1836 and 1838. The first 2.5 miles (4.0 km) of the London and Blackwall Railway (1840) was also built on a viaduct.
It was the first steam railway in the capital, the first to be built specifically for passengers, and the first entirely elevated railway.
The idea for the line came from Colonel George Thomas Landmann, until 1824 a Royal Engineer, and George Walter, and the company was floated at a meeting on 25 November 1831. It would run from close to London Bridge, convenient for journeys to the City. It would be some 3 3⁄4 miles (6.0 km) long, on a viaduct of 878 brick arches, the London Bridge-Greenwich Railway Viaduct, to avoid level crossings over the many streets which were already appearing in the south of London. Landmann planned to rent the arches out as workshops. The intention had been to descend to ground level after the Grand Surrey Canal but this was opposed by Parliament.
The first Act of Parliament was obtained in 1833 for a line from Tooley Street (now London Bridge) to London Street, Greenwich.
London Bridge-Greenwich Railway Viaduct
The London Bridge – Greenwich Railway Viaduct consists of a series of nineteen brick railway viaducts linked by road bridges between London Bridge railway station and Deptford Creek, which together make a single structure 3.45 miles (5.55 km) in length. The structure carries the former London and Greenwich Railway line and consists of 851 semi-circular arches and 27 skew arches or road bridges. It is the longest run of arches in Britain. It is also one of the oldest railway viaducts in the world, and the earliest example of an entirely elevated railway line. It was built between 1834 and 1836. The original viaduct had been widened for 1.95 miles (3.14 km) of its length between Corbett's Lane and London Bridge on the south side to accommodate the trains of the London and Croydon Railway and London and Brighton Railway, in 1842 and also for 2.65 miles (4.26 km) on the north side to accommodate the South Eastern Railway main line in 1850.