BTS Specification for Tunnelling – call for comments

19 March 2019

Great Britain – The BTS is seeking comments on its Specification for Tunnelling ahead of the next major revision. A blog has been created which will allow tunnelling industry professionals to provide their input, be it related to a single clause or to whole sections.

To contribute, please visit:

Clauses will be uploaded to the blog one at a time for consideration, but users will be able to provide feedback on earlier clauses. All comments must be provided with a name and affiliation; anonymous comments will be ignored.

The BTS Specification has become an standard industry document for tunnelling contracts, and forms the basis of many tunnelling specifications for projects throughout the world. The current 3rd Edition was published in 2010 and since then industry developments and site experience have led to the conclusion that a 4th Edition is needed. This new edition is due to be published in 2021.

“A particular point of discussion recently has been the tolerances of the precast segmental linings,” said BTS chair Ivor Thomas, “There have been significant increases in diameter and segment length since the last revision. The BTS has been contacted by CBE with suggestions and there is a half-day seminar planned for the autumn.”

Neil Moss, technical lead for the project (and author of the blog) added, “The major changes will be related to TBMs. There are a number of additional clauses that Gordon Ince and I wrote for the LU Tunnel specification T0006, which will be added. These will also be uploaded for comment on the blog. There are other changes included in T0006 such as monitoring, SCL construction and RESS/DR meetings that have developed since the last revision to the specification.”

As with previous editions, the latest specification will be divided into five Sections that contain relevant clauses:

  • 100 Series – General Requirements
  • 200 Series – Materials
  • 300 Series – Methods
  • 400 Series – Ground stabilisation processes
  • 500 Series – Working Environment

Thomas concluded, “It is the hope of the BTS that this blog will draw in comments from a wide base of users to ensure that the next revision is representative of industry best practice.”

For further information or if you have any queries, please contact: