The London Underground is composed of an extensive network of rail and pedestrian tunnels, along with a variety of related support facilities. Expansion or renovation efforts within this subsurface environment carry with them not only the usual challenges to underground engineering, but in some areas the additional challenge of working beneath some of the most expensive and architecturally significant buildings in the world. SubTerra, Inc., and its associates have been active participants in several major construction projects on the London Underground.

The project was constructed using the New Austrian Tunneling Method (NATM). This technique uses a combination of means to maximize the self-supporting capacity of the given soil conditions. Work by SubTerra and its associates included coordinating the intricate task of meshing required station geometry with the existing underground railways, pedestrian tunnels and services, deep basements, and an underground post office railway. Support was also provided in review of the work undertaken by UK consultants, preparation of design manuals, and input for the Parliamentary process. SubTerra’s UK Associate also participated in design of the key station at Liverpool Street.