Woolwich Foot Tunnel was dug by hand with the aid of a tunnelling shield. It connects the north bank of the River Thames near London City Airport with Woolwich, adjacent to the ferry. It was constructed to give local people free 24 hour access to the docks and shipyards on the north bank, whatever the weather. The tunnel remains open and is reportedly used by up to 300,000 people a year.
Before the foot tunnel was built, the only way to cross the Thames at Woolwich was by ferry — one has operated here since 1308. The present location of the ferry was established in the 19th century, when the Woolwich Free Ferry's paddle steamer service began on 23rd March 1889. The ferry terminals were rebuilt in 1964-6.
However, the ferry was often delayed or cancelled as a result of London's infamous thick fogs. As early as 1876, James Henry Greathead (1844-96) began a foot tunnel under the Thames at Woolwich, but it was never completed.
The present tunnel was designed for London County Council by the splendidly named Irish engineer Maurice Fitzmaurice (1861-1924, knighted in 1912). Fitzmaurice had been appointed chief engineer to the council in 1901, following the retirement of Sir Alexander Richardson Binnie (1839-1917), and he also designed Rotherhithe Tunnel and Vauxhall Bridge (with Binnie) for them.
On 16th August 1909, the Thames Tunnel (North and South Woolwich) Act received royal assent. In March 1910, a contract for constructing the tunnel was let to Walter Scott & Middleton for £78,860.
On 1st May 1910, construction work began with the access shaft on the north river bank. The shaft had been sunk to its final level in September, then tunnelling began on 1st December 1910. It was completed in October 1911.
The tunnel was driven using a tunnelling shield but the excavation was carried out by hand. Men worked inside compartments at the face of the shield, digging with picks and shovels. Compressed air was used to prevent the surrounding ground from collapsing during boring. At its deepest, the tunnel roof is about 3m below the river bed.
The tunnel is lined with a cast iron tube of 3.9m exterior diameter, consisting of a series of rings joined together. Tunnellers worked around the clock in three eight-hour shifts and managed to dig an average length of 2.5m — or five rings — every 24 hours. The cast iron lining is faced in concrete set with glazed white tiles, and the 2.8m wide footway is paved with York stone flags.
The vertical shafts at each end of the tunnel are caissons formed from two cylinders of steel plate filled with concrete. Both shafts were sunk in a compressed air environment and have brick linings finished to an internal diameter of 7.6m.
The distance between north (TQ431797) and south (TQ432792) shafts is 504.4m, centre to centre. Access to the tunnel is via winding stairs inside the vertical shafts. The northern shaft has 126 steps and is 19.5m deep. Lifts were not included in the original design. However, electric lifts for up to 40 passengers were later installed in each of the stairwells, at an additional cost of £5,000.
The ground-level entrances to the access shafts are circular rotundas of red brick with blue brick plinths, and conical timber framed roofs clad with lead and copper topped by circular lanterns. Each has a canopied doorway with cast iron columns, paired sash windows with wrought iron grilles set in square recessed panels and a panelled parapet with stone coping.
On 26th October 1912, the tunnel was opened by Major-General Herbert Francis Eaton (1848-1925, third Baron Cheylesmore), the Chairman of London County Council. Both tunnel rotundas are now Grade II listed (1989).
Though built for pedestrians, the tunnel also acts as a route for services including a 508mm diameter water main with a number of risers.
In 2001, in response to rust and water staining, the tunnel’s external drainage was improved, and a water manifold and four vertical ducts were sealed. However, the problems persisted. A survey indicated that high moisture levels in the brickwork corresponded with conduit and service positions. Further investigation attributed this to the relatively poor quality original brickwork, which contained voids and allowed water to percolate through, bringing rust from iron and steel wall fixings.
A programme of refurbishment works was carried out during the period 2009-14, as part of a wider heritage project that also covered the Greenwich Foot Tunnel. Both tunnels have been restored.
At Woolwich, the roof of the south rotunda had been vandalised and its copper cladding had twice been stolen, leading to leaks. The roof was repaired with 300 sq m of copper-faced membrane, which looks the same as the original but has no value to metal thieves. New lifts were also fitted inside the original interiors, the stairs renovated, lighting upgraded and full CCTV coverage installed.