Silvertown Tunnel - total project costs

MQT on 2015-01-21
Session date: 
January 21, 2015
Question By: 
Darren Johnson
City Hall Greens
Asked Of: 
The Mayor


Please list all of the different "total project cost" amounts that TfL has ascribed to the Silvertown Tunnel during its various consultations on river crossings. Please give reasons for any increases in project cost between each consultation.


Answer for Silvertown Tunnel - total project costs

Answer for Silvertown Tunnel - total project costs

Answered By: 
The Mayor

As with all major infrastructure projects, the projected cost of the Silvertown Tunnel project has changed over time as the scheme has developed and assumptions have changed. 

For the River Crossing consultation, which ran from October 2012 to February 2013, TfL had estimated that the project would cost in the region of £600 million. This was a preliminary cost based on comparisons with similar projects.

In TfL's September 2013 response to the River Crossing consultation, it published a revised cost estimate for the scheme of £700 million. The £100 million revision to the scheme's cost reflected revisions to development costs including allowances for land purchase, planning, procurement and project management and assumptions supporting the construction costs.

For the most recent Silvertown consultation, which ran from October to December 2014, the scheme's cost was revised to £750 million. The cost increase reflected a change in the project's technical scope including tunnel safety, increasing the base construction cost, and an adjustment to inflation assumptions and risk allowance.