The overall value of the 30-year contract is roughly $2.7 billion, with construction of the bridge and approaches accounting for some $760 million. The bridge represents about half that.

The competitive pricing stemmed from the depressed economy following the 2008 banking crisis, Nicholson believes, but the crisis also undermined the project finance market. HBC agreed to contribute about $150 million of financing, which it would borrow on its own balance sheet. That left the private sector to raise around $760 million, including 15% in equity and subordinated debt.

Crucially, a new infrastructure-bond- guarantee scheme had just become available. The government launched the scheme in late 2012 to ease project financing and help revive the moribund bond market. Without the guarantee, the financing "would have been a challenge and much more expensive," says Chris England, FCC's U.K. P3 manager.

To help fund construction and long-term operating costs, HBC secured from the government a $131-million capital grant and a $21-million annual toll subsidy. Toll charges will provide around 90% of the funding.

HBC's early decision to take responsibility for tolls relieved the private operator of revenue risk and eased procurement, says Hugh O'Connor, Merseylink's general manager. Otherwise, "we would have had to think long and hard" about bidding, adds FCC's England.

But agreeing on terms for Merseylink's hand-over of the tolling system to HBC was one of the most challenging aspects, says Nicholson. "Potentially, we were faced with a difficult interface where the bridge could be finished and we would be contractually obliged to pay Merseylink … and SANEF was not ready to operate the tolls," he explains. Merseylink was not interested in taking responsibility for SANEF's operations after construction.

Finally, Merseylink agreed that SANEF must demonstrate successful toll operations before handing them over to HBC and starting to earn operating fees. At that time, SANEF will become HBC's contractor, charged with collecting tolls for users of its free-flow electronic system. SANEF will carry the risk of unpaid tolls up to an agreed-upon limit.

Spanning Mudflats

The link will cross environmentally sensitive mudflats on four cable-stayed spans, ranging in length from 181 meters to 381 m. The three river piers are arrayed asymmetrically to avoid disrupting streams.

Since financial close last March, MJV has built much of a temporary trestle access bridge over the river. It is working on two pier cofferdams and will start the third this spring. The 7.5-m x 8-m foundations will reach some 10 m below the riverbed, according to Jennifer Douglas, who was FCC's technical bid leader.

The tower heights will vary from 125 m above water level at the south to 80 m in the middle and 110 m at the north. The trapezoidal prestressed-concrete box-girder deck will have a constant depth of about 4.5 m and a 33 m minimum width.

MJV will cast the deck out from each pylon on traveling formwork, says Douglas. It plans to cast 6.5-m-long sections between cables at a rate of about one every seven days. The cable sub- contractor's appointment is imminent, adds Douglas.