You carried a report of the recent Railway Civil Engineers Association seminar in Manchester (NCE 22 September). The construction of Crossrail is a challenge rather than anything to be feared.
Cross London Rail Links (CLRL) is working with the tunnelling industry, through the British Tunnelling Society, to plan ahead for these works to ensure the availability of a skilled and trained workforce spanning from management through to production.
Specifically on the subject of sprayed concrete, the tunnels constructed by the sprayed concrete lining (SCL) method will have fully engineered linings.
These will be designed for all foreseeable conditions including the intermediate stages of construction.
Monitoring will be employed to verify the predicted performance of the linings and ground movements during and after construction.
As with other forms of construction, changes would only be made on the basis of a full engineering assessment and design.
Bernard Gambrill, head of public affairs, Crossrail, 1 Butler Place, London SW1H 0PT