A temporary double-decker bridge could allow the Hammersmith Bridge to reopen next summer, initially to pedestrians and cyclists, with motorists following a few months later, Hammersmith and Fulham council has announced.
However, it would also become a toll bridge, with early assessments indicating that motorists might pay an average of £3 to drive across the bridge.
The Grade II* listed bridge was closed on safety grounds on 13 August 2020 after cracks in the cast iron pedestals widened during a heatwave. Since then, apart from the engineering tasks of working out how to repair it, there’s been a very heated political debate about who and how will pay for the repairs, which are estimated to cost around £140 million.
TfL is currently looking at a temporary replacement ferry that would carry pedestrians and maybe cyclists, but with the bridge closed to motorists, a long term solution is needed.
The idea of a double-decker structure being slotted into the existing bridge was announced last November, and since then, Foster + Partners, and bridge engineers COWI have been working on verifying that the proposal is viable.
The main concern was whether the existing bridge foundations could support the inserted bridge, and it’s now been announced that they can.
As well as delivering vehicle access earlier than the current restoration plan, the proposal has been initially costed at around £100m – offering a potential saving of approximately £40m.
The double-decker scheme would involve launching a truss structure above the existing road deck with a lower level for pedestrians and cyclists and an upper level for cars and buses. If it goes ahead, then Hammersmith Bridge could potentially reopen for pedestrians and cyclists next summer, and motor vehicles a couple of months later.
While the double-decker insert is in place, elements of the bridge that need repair, including the decking, would be lifted away using the temporary bridge as a works platform and transported by barges to an off-site facility for safe repair and restoration.
According to the feasibility report, provided planning and procurement is in place by the end of this year, the bridge could reopen for pedestrians and cyclists by the summer of 2022 and motor vehicles two months later, four years sooner than the current plan. The full restoration could be completed in 2023.
The aim is to eventually then remove the double-decker insert, returning the bridge back to its conventional state.
The council is also looking at transferring ownership of the bridge into a charitable trust, with the income from the toll crossing funding its maintenance in the long term. The Government has been asked to fund the costs of the borrowing, stabilisation and any other upfront costs in the period prior to the road charging taking effect.
The findings of the feasibility study will be discussed at next week’s meeting of the Government’s Hammersmith Bridge Taskforce.
The council has not ruled out other options, such as the temporary ferry at the moment.