lauraday

hi
in london or the other cities that have a subway how deep is the subway?

Steve Crook

The London underground varies in depth quite a lot. Much of it, especially on the outer fringes, is running at ground level, not in tunnels. Even some short sections in central London are above ground.

A lot of the first lines were laid using a "cut and cover" technique so aren't very deep. The tracks are only about 5m (15 feet) below the surface. Other lines are "deep bore" lines were properly tunnelled. The cut and cover lines are so near the surface that you can't build anything above them. There are a few places where there are dummy houses with false fronts to preserve the appearance of a row of houses from the road.

Hampstead has the deepest lift shaft at 55.2m (181 ft) and is the deepest station at 58.5m (192 ft) below ground level. Probably helped by Hampstead being on a hill so if the tube line stays roughly level there's further to go from the surface to the tracks. The Underground's deepest point below ground level is at Holly Bush Hill, Hampstead, 67.4m (221 ft)

Angel station has the longest 60m (197 ft) escalators in western Europe, which take 80 seconds to carry passengers up or down the 27.5 m (90 ft) drop. Morden (my local station) is the most southerly point served by the Underground, 16km (10 miles) from central London. The tunnel between East Finchley and Morden (via Bank) is the Underground's longest and one of the longest rail tunnels in the world, 27.8km (17.25 miles). The Dollis Brook viaduct over Dollis Road on the Mill Hill East branch is the highest point above ground level on the Underground, 18m (60 ft) above ground level.

These and other facts at Tube Facts on the TfL (Transport for London) site

Steve