The BTS Specification for Tunnelling has become the standard industry document for tunnelling contracts, and forms the basis of tunnelling specifications for projects throughout the world. The specification has been revised in this third edition to reflect current industry best practice and to take account of the many advances in the field of tunnelling which have occurred over the last decade. All references to codes, standards and other design documents have been comprehensively updated. Specification for Tunnelling, 3rd edition was drafted by an expert editorial committee with more than 250 years experience in the tunnelling industry between them.