Crossrail is being delivered through contracts between Crossrail Ltd and a range of private sector suppliers, including programme delivery partners, Bechtel and Transcend (a consortium of AECOM, CH2M Hill and Nichols Group), Siemens, and other joint ventures from firms including Alstom, Costain, Skanska and Balfour-Beatty. These main contractors have contracts with other suppliers for the supply of services, materials and components of the railway. The contract to design, build and maintain the trains is between TfL and Bombardier Transportation.
Although Network Rail is a public sector body sponsored by the Department, on the Crossrail programme it functions as a partner to Crossrail Ltd, funded directly by the Department, with its responsibilities set out in the protocol agreement between Network Rail and Crossrail Ltd.