Tower Subway | The story behind London’s lost underwater railway
This short-lived river tunnel provided a test run for the engineering used to build the world’s first deep-level railway, aka London’s tube.

The 1920s reconstruction of the subway entrance on the Tower Hill side
Situated just a few hundred metres from the Tower of London is a remnant of a lost transport system. A short circular building near the junction of Petty Wales and Lower Thames Street commemorates the former Tower Subway, which briefly transported passengers under the river in the 1870s. Although it closed 150 years ago, this 20th century reconstruction of its northern entrance reminds us of a pioneering piece of Victorian engineering.
The population of London swelled hugely during the Victorian era, prompting widespread building of bridges and transport to move the masses around the capital. The Thames Tunnel, which originally opened to pedestrians in 1843, was converted to train use by 1869. Meanwhile, the first tube, the Metropolitan Railway, opened in 1863. Keen to capitalize on the growing demand for these new transport methods, London-born engineer Peter W Barlow (1809-1885) patented a new method of tunnelling, in the hope of creating a network of tunnels to carry people under the city. City bosses were wary of the cost after the spiralling budget, deaths in construction and the 18 years it had taken to build the Thames Tunnel. However, Barlow’s pupil James Henry Greathead (1844-1896) said he could make the first cylindrical tunnelling shield (patented by Barlow) and use it to build a transport tunnel system under the Thames for £9,400.
Greathead’s project kicked off in February 1869, with the cast iron shield used to dig through the London clay – the first time this construction method had been used. The tunnel was 1,340 ft long, connecting Tower Hill on the north of the River Thames with Vine Lane near Tooley Street on the south. Inside the tunnel was a 2ft 6in gauge railway, which carried up to 12 passengers under the river in a cable-hauled wooden carriage in about 70 seconds. The lifts from street level to the tracks, as well as the cable car, were powered by a 4hp stationary steam engine on the London Bridge side of the tunnel. The rapid construction proved the tunnelling shield was a success and it was later used to build the City and South London Railway, the world’s first deep-level underground railway.
The tunnel was completed in less than a year with it taking its first passengers in February 1870. It appeared to have a ‘soft launch’ in April 1870, before being opened to the public four months later. Robert Miles commented in the British Almanac that the brief journey wasn’t exactly pleasant: “The temperature of the Subway is certainly rather high, but it only has to be borne with for a brief space. The passage is somewhat rough, the movements of the omnibus being jerky, especially at starting.” Initially, there were plans for similar tunnels at Gravesend, Woolwich and Greenwich, Cannon Street and Borough. However, by 7 December that year, the Tower Subway cable car ceased after the company ran into financial problems. Just a few weeks later, the tunnel was converted for pedestrian use, with customers paying a halfpenny to use it. The lifts were removed and replaced by a flight of 96 stairs, with gas lights being placed throughout the tunnel. At the height of its popularity, 20,000 people a week were using the tunnel, despite its reputation for being dark and claustrophobic.
As the end of the century approached, the Tower Subway’s fate was sealed when Tower Bridge opened locally in 1894. The latter was not only free to use, but pedestrians had the choice of crossing the river at vehicle level or by using the high-level walkways – a much more pleasant option than a dark, cramped tunnel. By 1897, the Tower Subway company applied to dissolve the company and closed the tunnel the following year. It sold the tunnel for £3,000 to the London Hydraulic Power Company (LHPC), who used it for power mains.
The original Tower Hill entrance to the Subway was later demolished, with the LHPC building a reconstruction in 1926, with lettering commemorating the original construction date. The tunnel was damaged by a Nazi bomb in December 1940, but amazingly its lining wasn’t penetrated and it was able to be repaired. Meanwhile, the original Vine Lane entrance on the south side of the Thames was later demolished around the 1980s-1990s.
- Tower Hill Subway, Tower Hill, EC3R 5BT. Nearest station: Tower Hill, Fenchurch Street or Tower Gateway.
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Posted on 27 Aug 2020, in History, London and tagged engineering, London Transport, River Thames, tube. Bookmark the permalink. Comments Off on Tower Subway | The story behind London’s lost underwater railway.