Ty Bridge Pier Collision Protections

Tay Road Bridge Joint Board                                   Client                   

Dundee City Council City Engineer’s Division         Engineer to the Board, Professional Services
                                                                              Advisor and Supervisor

Jacobs UK Ltd                                                        Designer and Delegated Project Manager          

VolkerStevin                                                          Contractor        

The Tay Road Bridge provides a vital link between Dundee and Fife, and carries around 25,000 vehicles a day.

There are navigation channels below the bridge and ship collision is therefore a significant risk to the safety of both the structure and users. Since opening in 1966, the bridge has been struck three times, fortunately without suffering any significant structural damage. However, any lengthy closure as a result of a serious ship impact would have dire consequences for the local economy with losses of hundreds of millions of pounds.

As part of its responsibility for the safe operation of the bridge, the Tay Road Bridge Joint Board decided to take forward this project to reduce this risk to as low as reasonably practicable at the piers adjacent to the navigation channels. Jacobs UK Ltd was commissioned to undertake the design and prepare a bespoke two-stage Early Contractor Involvement contract for the construction of the works. This was followed in early 2011 with the award of a £15 million contract to VolkerStevin Marine UK following a competitive tender process.

During the first stage of the contract the Client, Designer and Contractor collaborated on the ground investigation works, developing the detailed design and construction methodology, programme and target cost. This approach enabled the parties to optimise the proposals to suit the characteristics of the site and demanding marine environment, which included a large tidal range and strong currents. The Client also benefitted from greater cost and programme certainty prior to the decision to proceed to stage two of the contract.

The second stage began in March 2012 and involved a range of major operations, including marine piling and scour protection, onshore pre-casting works, heavy lifting and transportation on land and water, and large in-situ concrete placing operations.

Although the works were carried out in close proximity to the bridge, it was not possible to use the bridge deck as a working platform or for access as it had to remain open to vehicular traffic and pedestrians.

A navigable channel also had to be maintained at all times for shipping. This necessitated the use of substantial floating plant, including a large crane barge, to undertake the works with all plant, materials and labour being transported to the site by boat.

Despite the hostile marine environment, the project was completed ahead of programme and within budget, without incident or disruption to either road or maritime traffic. The project demonstrates an exceptionally high level of civil engineering expertise in a demanding environment to provide a system that will protect one of Scotland’s most important bridges against ship collision.