The Victoria Tunnel was considered as an addition to Merseyrail in 1975. At Liverpool Central station, spur works were built to enable a tunneled connection to the Victoria Tunnel and so to Edge Hill station and the inner loop, which would have allowed stations like Breck Road station to reopen as part of the MerseyRail system.
External link
London and North Western Railway Society website (http://www.lnwrs.org.uk/Sales/portfolio10.php)
There are many bridges and tunnels crossing the Thames, including Tower Bridge, London Bridge, Lambeth Bridge[?], and the Dartford Crossing.
There are also many tunnels used by "tube" trains as part of the London Underground network or (at Greenwich), the Docklands Light Railway, and a free ferry for vehicles, cycles and people on foot during daylight hours at Woolwich.
A further tunnel is under construction as part of a high speed international railway line between Ebbsfleet in Kent and Stratford in Newham[?].