Wednesday 30th October 1991

The Queen Elizabeth II Bridge was officially opened by Queen Elizabeth II. The total cost of construction was £120 million (£246 million as of 2015), including £30 million (now £58 million) for the approach roads.The proposed name had been simply the Dartford Bridge, but Thurrock residents objected and suggested the Tilbury Bridge, leading to a compromise. At the time of opening, it had the longest cable-stayed span of any bridge in Europe. It is the only bridge across the Thames downstream of Central London to be opened since Tower Bridge in 1894.

During the early 1980s, it was anticipated that traffic through the tunnel would rise on the completion of the M25 in 1986. At the time, the expectation was that other routes in London would be improved instead, diverting 15% of traffic away from the tunnel. In 1985, the Transport Minister, Lynda Chalker, announced that the number of toll booths would be increased to 12 each way, but concern grew that two tunnels would not be able to cope with the full demands of a completed M25.
Between September 1985 and December 1986, proposals for improvements to the Dartford Crossing underwent several changes, and in 1986, a Trafalgar House consortium won a bid to build a new bridge at Dartford crossing, valued at £86 million (now £227 million).[39] At the time there were several other privately financed projects planned or under construction in the UK, including the Second Severn Crossing. From 1981 until the establishment of the Private Finance Initiatives (PFIs) in the late 1980s, private investment projects were governed by the Ryrie Rules which dictated that “any privately-financed solution must be shown to be more cost-effective than a publicly-financed alternative, and that privately-financed expenditure by nationalised industries could not be additional to public expenditure provision, which would be reduced by the amount of private financed borrowed.”
On 31 July 1988, a Private Finance Initiative concession was enabled under the Dartford-Thurrock Crossing Act 1988, which transferred control of the crossing from Kent and Essex county councils to Dartford River Crossing Limited, a private company managed by Rodney Jones.[54] The company would also bear the debt of the bridge, then under construction, “financed 100% by debt, with no equity contribution”.[55][e] The private company was at risk of not recuperating their costs, but ultimately the Dartford scheme demonstrated that the Ryrie Rules were no longer a barrier to the private financing of public infrastructure projects.[57] The concession was scheduled for 20 years from the transfer date, with a stipulation that it could end when debts had been paid off, which was agreed to have been achieved on 31 March 2002. According to the International Handbook on Public-Private Partnership, the chief financing for the project came from a “20-year subordinated loan stock, 16-year loan stock and £85 million [now £206 million] as a term loan from banks”.
Construction of bridge started immediately after the creation of the PFI in 1988.It was designed by German civil engineer Hellmut Homberg (de), and the two main caissons supporting the bridge piers were constructed in the Netherlands. Each caisson was designed to withstand a bridge strike of a ship weighing up to 65,000 tonnes and travelling up to 18.5 kilometres per hour (11.5 mph) The bridge deck is about 61 metres (200 ft) high, and it took a team of around 56 to assemble its structure. During construction of the approach road, a World War II bomb was found in its path, which required closure of the entire crossing.