150. Some projects are deemed too big for private finance as they would require the contractors to take on more risk than they would be prepared to. Crossrail was viewed as one such project. Mr Allen said: "You would struggle to find sufficient equity in a consortium vehicle to back that kind of risk … I think one of the lessons might be that the London Underground PPP contracts were too large to structure efficiently" (Q 379).
151. However, private finance can be used for part of Crossrail. Ms Mingay said: "On these very large projects you often have projects within projects-that there are elements where private finance can be incorporated into the deal. Again in Crossrail it is the rolling stock and the construction of the Canary Wharf Station being done by the private sector, where the rest is being done publicly" (Q 543).
152. The projects most suitable for private finance are those where the requirements can be clearly specified at the outset and which are of a size that consortia of private sector companies can take on their balance sheets.