Search results
Results from the WOW.Com Content Network
A tunnelling shield is a protective structure used during the excavation of large, human-made tunnels. When excavating through ground that is soft, liquid, or otherwise unstable, there is a potential health and safety hazard to workers and the project itself from falling materials or a cave-in. A tunnelling shield can be used as a temporary ...
Another patent by Greathead was the addition of the grouting pan at ceiling height that allowed cement grout to be applied hydraulically behind the vast cast iron shields to stabilise the tunnel wall outside the shield sections. A third tunnelling shield was patented by Greathead that introduced hydraulic pressure nozzles at the tunnel face to ...
present. (present) [2] Secrets of the London Underground is a British factual documentary series presented by railway historian Tim Dunn and London Transport Museum 's Engagement Manager Siddy Holloway, co-developer of 'Hidden London', the museum's programme of tours that gives visitors access to disused and historical parts of the network. [3][4]
Constructed using a circular tunnelling shield developed by Peter W. Barlow and James Henry Greathead and lined with segmental cast-iron rings, this short tunnel under the River Thames successfully demonstrated new tunnelling techniques that would be used to construct most of the subsequent underground lines in London. [15]
Tunnel boring machine. A tunnel boring machine (TBM), also known as a "mole" or a "worm", is a machine used to excavate tunnels. Tunnels are excavated through hard rock, wet or dry soil, or sand, each of which requires specialized technology. Tunnel boring machines are an alternative to drilling and blasting (D&B) methods and "hand mining".
The Tower Subway is a tunnel beneath the River Thames in central London, between Tower Hill on the north bank of the river and Vine Lane (off Tooley Street) on the south. In 1869 a 1,340-foot-long (410 m) circular tunnel was dug through the London clay using a cast iron circular shield independently invented and built by James Henry Greathead ...
The Greathead tunnelling shield in use on the Waterloo & City Railway The route starts from a point south-east of Waterloo main line station, halfway between Lower Marsh and the now-vanished Aubyn Street, which was destroyed in the station's early 20th century expansion and was located more or less where today's platforms 3 and 4 are.
James Henry Greathead (Barlow's pupil), independently designed, patented and built the first cylindrical tunnelling shield used on the 11-month construction of the Tower Subway in 1869 and 1870 - the second tunnel under the Thames. Barlow was the engineer with Greathead as the contractor, according to W. C. Copperthwaite in his 1906 book on ...