Foster & Partners bridge proposal

Hammersmith Bridge would seem to be a unique and most deserving case for special funding, and it is so frustrating that the critical issue of project financing is not addressed in the government Task Force meetings, despite its obvious importance. However we understand that, separate to the Task Force meetings, LBHF have been exploring initiatives which draw on the private sector, not only in the Foster/Ritblat temporary bridge proposal, but also investigating the viability of private funding, secured on an income stream provided by a toll: this financing method which has been used for a number of other UK bridges, including in London, the Dartford Crossing. LBHF residents would be likely to cross toll-free. We understand LBHF have now submitted a comprehensive financial plan to Grant Shapps based on this funding approach.  Consideration might be given to 1% of the toll to be set aside for social funding in Hammersmith, similar to the arrangement on the London Eye ticket price.

Some valuable comparative information has emerged regarding the financing of other London bridges. For the recent £9.6M repairs to Albert Bridge, RBKC paid £2.6M in line with many other bridge repairs as recent research indicates, while TfL paid £7M. The £9M refurbishment of Chiswick Bridge was paid for by TfL. Since TfL are out of funds, the recent upgrade of Wandsworth Bridge was paid for by Wandsworth Council – but since the bridge is a simple cantilever structure, fabricated in steel in 1940, the overall cost was only around £6M, less than 6% of the bill for the 1887 Hammersmith Bridge.

These comparative repair costs highlight the unique problems with the bridge, an ornate, Grade II* listed structure constructed from cast iron and wood in 1887, two years after the first internal combustion engine came off the Benz production line. Before the traffic closure in April 2019, over 20,000 vehicles and 2,000 single-decker buses were crossing the Bridge daily; until total closure in August 2020 16,000 pedestrians and cyclists were crossing daily. Until 1998 heavy goods vehicles and double-decker buses were using the Bridge.

The Bridge is clearly not fit for this purpose. If the outward appearance of the Bridge is to be retained, then within the decorative outer claddings the structure has to be not repaired, but replaced, to create a Bridge which is able to sustain the demands of 21st century traffic.  We discuss this in more detail in the accompanying article.

Site work and a temporary crossing

Site work: Current activity on site is limited to the stripping back and investigation of the two up-river pedestals, which secure the ends of the suspension cables on the west side. This work is being undertaken by Kier contractors and funded from the £1.8 billion second TfL bail-out received from the government in November.

Bridge anchor (cover removed)

As we pass six months since complete closure, we’ve made it crystal clear that there appears very little, if any, value in repairing the much-debated, though normally invisible, cast iron pedestals shown.  We continue to be dismayed that so much attention is paid to evaluating and repairing these simple yet demonstrably unsuitable bolted-in components (c.f. Mott MacDonald summary and more detailed  Aecom report) when replacement with modern equivalents is an obvious solution.  Not only that, but by including, as we’ve suggested, a built-in lifting or jacking mechanism for the chains in a new design pedestal, future maintenance inspections and bearing replacements (the cause of many of the current problems, and certainly the precipitous closure), would be reduced to perhaps scheduled weekend roadway closures every 5 years or so, at low cost and public impact.  This, without even considering the environmental and financial running costs of the proposed chain heating and monitoring systems that would no longer be needed. 

Surely we can’t be the first to spot such an opportunity for a better and long-lasting engineered solution at lower overall cost – plus the opportunity to cut a whole phase of repair work ? The question is why can we only find passing reference to renewal as an option in the copious Aecom report?  Which is where we return to the issue of the premise, assumed to include retaining the original components.

A false premise

Temporary pedestal support frame

The TfL drawings shown at the public meeting in October, to which we responded, show a temporary support frame for “emergency stabilisation” – already designed – that could be better used during pedestal renewal, using offsite built and tested replacements, instead of a long and expensive (£13.9M + percentage  – say half – we don’t have a detailed cost breakdown) of the permanent stabilisation costs, totalling £30M. 

The current proposal for onsite shoring-up would hardly respect the Grade II* listing, Bazalgette’s design, or materials (assuming that’s the rationale), rendering the pedestals unrecognisable as historic components, especially when infilled with [c. 6 tonnes] of steel fibre reinforced concrete as proposed, and would, according to the Aecom report, leave further nascent cast-iron problems, including a possible failure mode where the cast iron collapses onto the unusual prop/concrete/cast iron mix. The cast iron pedestals would instead make fine museum pieces, to accompany Tower Bridge’s stream engine, removed from service when proven equally obsolete over 40 years ago.

Foster & Partners / Delancey temporary bridge proposal

Bridge proposal

• Raised temporary deck envisages crossing for vehicles, pedestrians and cyclists on 2 levels.
• The deck would overlay and rest on the footings of the existing bridge.
• River traffic could pass underneath.
• Costs believed lower and timescale significantly faster than previous plans.
• Partial dismantling and offsite refurbishment of the existing structure while temporary structure in place.
• Transport Secretary given outline brief by H&F Council Leader on 25th November.

There’s been generally positive comment in the press and social media, and we were particularly pleased to see our favoured approach of offsite construction/restoration being embraced, which should improve the quality of the end result.

Funding

Since the public Task Force meeting in October, there have been snippets of gossip from behind the scenes, but little significant  progress to report. TfL have been instructed to pay for a temporary ferry river crossing, and to contribute £4M towards the bridge stabilising work, drawing from their recent £1.8B government emergency funding.

Central government has now promised to fund the project, conditional on a substantial contribution from the local authority.  LBHF report that funds are not available to meet this demand.  The Hammersmith Society and others are pressing the government to take the long view, and release the Bridge funds now, and negotiate separately with the local authority,  and this is set out in our letters to the Task Force chairman and the Secretary of State for Transport, as previously published.

Enquiries to LBHF and other parties have revealed some further context to the funding problem.  We understand that Hammersmith became involuntary owners of the Bridge in 1985, when the government abolished the GLC (Greater London Council); there is no record of a condition audit taking place at the time, and no maintenance arrangement accompanying the gift, which was perhaps a mistake.

In normal circumstances structural repairs to the bridges over the Thames have been paid for by TfL, with costs of a fraction of the c. £150M budget for Hammersmith Bridge;  this very substantial cost arises largely from the design of the structure with cast iron, and design restrictions on the repair methods imposed by Historic England Grade ll* listing status. 

 Letter to Grant Shapps MP, Secretary of State for Transport

Letter to Baroness Vere, Chair of Bridge Task Force

Letter to Dana Skelley, Director of Bridge Task Force

We’ve made suggestions borne of our various architectural & engineering experiences, and feedback from members who contributed, balancing aesthetics, cost-effectiveness, speed of the works vs. longevity & value to the public. 

We think the repairs might be done more quickly and cheaply, and the result might last longer and be more useful as a bridge, if the slightly modified approach were taken, as outlined.  As an alternative, we’ve also dared to think the unthinkable given the proposed closure duration and costs, and suggested bridge replacement. An architectural competition could be held to decide how to best reuse what is there, but make it fit for the next century as Bazalegette did to the 1827 original, back in the 1880’s.  As we’ve said, this need not involve a total loss of the iconic appearance; it would be up to innovative designers to come up with the solution – we’ve already seen ideas coming from local architects and engineers.

With huge sums of central Government capital and revenue expenditure being regularly announced, the cost of solving the Hammersmith Bridge problem seems small by comparison, and given the considerable inconvenience already endured both sides of the river by some of the most vulnerable members of society, the project deserves immediate and full financial support.

Our report on the meeting has to tread carefully to resist the winds of political bias which seem to be jeopardising project navigation. The exchange of letters between the chairman of the Task force and LBHF reveals the entrenched and opposing positions of government and local authority concerning the funding of the bridge repair programme. At the meeting the Task Force chairman declared that the government is ‘completely ready to fund the entire project subject to local contribution’ – the proportion of this contribution was not defined – while the LBHF deputy leader reported that substantial local authority contribution has already been paid out for the bridge work to date, and LBHF could not afford any further funding. 

Alongside the funding impasse, the meeting provided an excellent explanation of the bridge problems, the anticipated repair works, the investigations in progress, and proposals for temporary pedestrian crossings.

A summary of the current critical issues:

• Project funding: government funding is confirmed conditional on LBHF contribution; LBHF and TfL have no funds available to contribute. TfL to fund the ferry crossing and contribute £4M towards the stabilisation works as a condition of their £1.7B second government support grant.
• Engineering works: completion of pre-design survey work requires a further 4-month programme to inspect each upstream pedestal (the lower housings at each end of the suspension chain); the contractor is ready to proceed with the work on release of funding. See project funding statement above.
• Project Plan: LBHF report that they have provided the ‘robust project plan’ called for by the chairman. We would expect to see a review of alternative options including the replacement of the bridge with a modern structure, taking into account the cost and programme viability of restoring a bridge built over 130 years ago for a very different traffic type and density. 
• Temporary crossing (stage 1): ferry transport for pedestrians and cyclists has been investigated and can be operational within 66 days of contract commitment and release of funding.  See project funding statement above.
• Temporary crossing (stage 2): pedestrian and cycle use of the bridge can be resumed for a  limited period after installation of temporary stabilising frames over the pedestals.  Obtaining the necessary statutory planning consents and carrying out site construction would require around 7 months; estimated cost is £14M.  See project funding statement above.
• Project programme: overall period for completion of the works as currently foreseen, including measures to meet TfL increased traffic loading requirements, is estimated at approximately 6 years – from release of funding.

Bridge permanent stabilisation – cast iron pedestals – slide from meeting

We’re a little concerned that substantial time and costs are currently being allocated for shoring up the cast iron pedestals that are clearly a long way past their best:  4 months/£2.3M blast cleaning prior to 7 months investigation and temporary stabilisation/£13.9M, followed by 21 months/£32M permanent stabilisation, in addition to a planned temperature control system to lower the risk of further cracking.

Hammersmith Bridge closed: Motor traffic:10th April 2019; Completely:13th August 2020

After much media/social media coverage, including stories on London TV news, a task force was set up on 9 September, chaired by Baroness Vere (roads minister), which includes representatives of the local councils, TfL and Network Rail (for their experience of cast iron bridges), the Port of London Authority and GLA. The task force’s project director is Dana Skelley, a chartered civil engineer, formerly director of roads for London and responsible for the London-wide roads modernisation ahead of the London Olympics and the repairs to Hammersmith Flyover.

Completing the full repair of the Bridge is currently predicted to cost £141-£163m, with stabilisation just to allow safe pedestrian and river traffic at £46m, considerably more than first envisaged.  We covered the announcement of a temporary pedestrian/cycle bridge in April, which is believed to have been costed at less than £10m.  Before lockdown, planning was to be sought for this during the summer with construction starting this autumn, but this has not happened.  We followed up in June with our ideas about widening the pathways while work progresses elsewhere, making the bridge suitable for safe bidirectional cycling and walking; these are also clearly ideas yet to be considered given the new circumstances of complete closure.

Neither the Council nor TfL can finance costs at this level, so government support is essential. The possibility of tolls to finance the work has not been ruled out, indeed some are campaigning for this to make more funds available to speed up the work.

Hammersmith Bridge underside and steelwork – May 2020

The Society’s committee is of the view that as part of the renovation work, there is a great opportunity to improve the Bridge to make it better suited to future needs, requiring more space for pedestrians and cyclists, as mentioned in our last article.  Our proposal is to widen the pathways to allow safe and satisfactory bidirectional walking on one side, and bidirectional cycling on the other, so that cyclists no longer need to compete with road traffic, significantly improving safety.  Currently, because of the somewhat narrow walkways, it’s not possible to safely cycle or even pass easily when walking, certainly not in a wheelchair or buggy.  We think this can be done both at modest cost (certainly compared with the 🔗Garden Bridge!) and largely independently of the planned repair works, so as not to lengthen the closure.  We have a brief update on repair works at the foot of this article.

The bridge’s narrow pathways for most of the span measure approximately 1.6m, widening at the pillars to approximately 1.8m, but still too narrow for bikes to pass safely (one of the reasons cyclists have to dismount currently), let alone to support social distancing needed now, and possibly in the future.  We’ve now looked at the structure in a little detail, and, as shown on the photos here, the pathways are supported by simple cantilevers, apparently bolted on.

Hammersmith Bridge – historical repairs (photo: Keepingthingslocal)

Steelwork underneath the bridge was repaired section by section in the 1970’s, and a new grid of substantial longitudinal girders replaced the originals (pierced where bridge hangers meet the deck). Historic photos (right) show the original, very much less substantial steelwork.  Given the scope of the repair works, and amount of money and time to be spent on repairs, there seems little reason not to now consider the attached pathways in more detail, especially if the planned temporary bridge removes the need to keep it open during the works.

TfL is planning a temporary footbridge parallel to Hammersmith Bridge at the request of H&F Council, to assure pedestrian and cycle transit throughout the repair programme.  The aim is to give over the entire Bridge space to the continuing works, with the result that the total closure time could be reduced by 9-12 months.

Hammersmith Temporary Bridge

In an online webinar on 3 April (replacing planned exhibitions which had to be cancelled), representatives of TfL and LBHF set out their scheme for a prefabricated steel structure supported by 2 piers in the riverbed, on the downriver side of Hammersmith bridge. It would be the same height as the Bridge and would have no impact on river traffic.   The usable deck would be 5.5m wide and there will be separation of cyclists and pedestrians (no motorbikes allowed).

Access would be via Queen Caroline Street on the Hammersmith side via gradual ramps. It would take 6-7 months to complete, and planning permission would stipulate it being in place for up to 5 years, with the aim of re-using the structure elsewhere afterwards.

Keeping foot and cycle traffic flowing has to be a welcome initiative. The one downside is that the structure would close the Thames Path on either side, meaning a detour – possibly via the rear of Riverside Studios or past the Apollo and round by Fulham Palace Road on the North side, and via Riverview Gardens on the Barnes side.

Meanwhile the pedestals, hangers, chain bearings and hanger connections are being worked on and acoustic monitoring of the Bridge structure continues. A detailed Scope of Works together with costs is expected later in the spring. The new deck will be steel, with resin on top, which will perform far better than the asphalt over boards which were alarmingly visible previously. The repairs will give 60 years of design life. 

Can we make the restored and repaired bridge work better in the future ?

Continued →