Tower Subway opens in London (1870)

The Tower Subway, a tunnel beneath the River Thames in London, opened for public use on 2 August 1870. It was the first underground passenger 'tube' railway, utilizing a cylindrical tunnelling shield independently invented by James Henry Greathead, who built upon Peter W. Barlow's earlier patents. The railway operated briefly until December 1870, demonstrating the viability of cast-iron segment lining and the cylindrical shield method.

Episodes

Background and detail

Background. The Tower Subway was authorized by the Tower Subway Act 1868 to connect Great Tower Hill to Vine Lane. Construction began in February 1869 with entrance shafts bored on both banks of the Thames. James Henry Greathead, a former pupil of Peter W. Barlow, tendered for the contract after Barlow's earlier rectangular shield designs had not taken practical form. Greathead independently invented and built a cylindrical cast-iron shield, distinct from Barlow's 1864 and 1868 patents, to drive the tunnel through London clay.

Technological Significance. The project demonstrated the practical use of a cylindrical tunnelling shield. While Peter W. Barlow patented a shield in 1864 and a provisional design in 1868, these were not built. Greathead patented a shield design that used water jets under pressure at the tunnel face to assist in cutting through soft earth. In 1869, Greathead in England and Beach in New York independently built similar shields. Greathead's invention is also the reason the London Underground is colloquially named the "Tube".

Operation and Closure. The tunnel was completed in February 1870. It opened to the public on 2 August 1870 as a narrow-gauge railway, using a cable-hauled wooden carriage. Passengers paid 2d for first class and 1d for second class. The railway operation was short-lived; the company entered receivership in November 1870, and the railway closed on 7 December 1870. The tunnel subsequently reopened to pedestrians in December 1870, becoming a popular crossing point.

People involved

Sources

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.