Chartered Institute of Building Magazine of the Chartered Institute of Building


Foster + Partners proposes ‘double decker’ Hammersmith Bridge

30 November 2020
Artist’s impression of the ‘double decker’ structure (Image: Foster + Partners)

Foster + Partners has put forward plans to create a temporary ‘double decker’ crossing over Hammersmith Bridge, which has been closed on safety grounds since August this year, to Hammersmith and Fulham Council.

The architect said the crossing would enable pedestrians, cyclists and, potentially, motor vehicles to be able to use the bridge during its repair and restoration, which the repair work undertaken offsite.

It has proposed a new raised truss structure would be built above the existing road deck, featuring a lower level for pedestrians and cyclists and an upper level for cars and buses. The raised deck would enable existing approach routes for traffic to be used.

The structure will also provide support for the bridge as well as a safe platform for restoration work to be carried out, it claimed.

The new truss structure would be assembled in two halves and launched from each side over the existing road surface. It would be supported on each bank and at the two existing piers. As a result, Foster + Partners said, there will be no added load on the existing bridge deck.

A horse and cart with passengers crossing Hammersmith Bridge during the Victorian era

The Grade-two-listed bridge needs repairs to its cast iron pedestals, anchors and chains. These would be lifted away and transported by barges to an offsite facility for safe repair and restoration under Foster + Partners’ plans. Contractors would use the new lower pedestrian deck to access the works. When completed, the temporary raised deck would be removed.

The proposal has been developed with bridge engineers COWI.

Luke Fox, senior executive partner at Foster + Partners said: “We are excited to propose this simple solution to what is an important missing piece of London’s infrastructure that also gives the opportunity to bring back to life a beautiful and iconic bridge by Sir Joseph Bazalgette.”

Roger Ridsdill Smith, head of Structural Engineering at Foster + Partners said: “We believe that our concept resolves the two challenges for Hammersmith Bridge economically and efficiently: delivering a temporary crossing quickly, whilst providing a safe support to access and refurbish the existing bridge.

“We appreciate the engagement and contribution from the technical experts and committees in charge of the bridge and look forward to further studies to develop the scheme.”

David MacKenzie, executive director at COWI, said: “We consider that this approach is practical and viable. Our experience is that offsite refurbishment of bridge structures is safer and more controlled, and results in a higher quality final outcome when the structure is re-installed.”