Transporting Tunnel Boring Machines
Summary
TBMs are rarely seen out in the open as they are often assembled and launched from portals or shafts with backshunts deep below ground. In some circumstances however, it is necessary to transport these huge machines whole. A task of this scale is a complex procedure and requires careful consideration and planning. The decision to transport a TBM will be influenced by many different factors, but may be considered more applicable to sites where the space available for assembly is at a premium, and projects where multiple launches are required along the route. A fast and efficient transit method therefore, is desirable to accelerate the programme of works and keep disruption to a minimum whilst maintaining high health and safety standards.
To provide a tangible example, this report draws on the experience of the engineers working on Crossrails Western Tunnels. This includes the transportation of two 1200 tonne, 140 m long TBMs from the assembly area, 600 m down to the launch portal. By presenting and analysing the various options available for transporting TBMs and considering the relative merits in terms of cost, time, risk, health and safety, operation and design, this report aims to provide guidance to parties considering undertaking similar operations. Conclusions are drawn highlighting the relative merits of the options available and the lessons learnt for the benefit of others.