Why do we need a bridge?
Currently around half of London’s population lives to the east, yet there is only one bridge downstream of Tower Bridge, and that is 20 miles away at Dartford. There are over 30 bridges serving the other half of the capital’s population, west of Tower Bridge.
Our proposal for a bridge at the Thames Barrier would be the only straightforward surface crossing for pedestrians and cyclists living east of Tower Bridge. The only other above ground crossings are the Woolwich Ferry and Emirates Cable Car, and they involve time consuming journeys and also, in the case of the Emirates, buying a ticket. People we have spoken to, complain about the unreliable lifts of the two Victorian tunnels under the river and cyclists also that they have to dismount and walk their bikes through. The only other options are to cross by tube or DLR under the river.
Why this location?
The Thames Barrier provides a key advantage in allowing us to put bridge supports down in the shadow of its piers, only minimally affecting river traffic navigation. Our design is for a relatively low bridge, around 15metres above Mean High Water Springs (the highest level that spring tides reach over the past few years). This means that it’s relatively easy for people to walk or ride up ramps at either end. When taller ships need to pass through, the 30m lifting sections in our design can quickly be raised and lowered. The only other option would be to have a very high fixed bridge, perhaps 50m above water so the large ships that use this stretch of the river can pass beneath.
Is it safe?
The opening spans consist of two 30m long bascules that swing open - they’re approximately the same length as those on Tower Bridge, so conventional in bridge engineering terms. We have suggested that up to four spans could open so that if one were to fail, then there would be backups available. Also the deep water either side of the Barrier, enables large vessels to anchor and wait if necessary.
Who would use it?
Our Transport consultants, Steer, estimate five million pedestrians and over one million cyclists would use the bridge for journeys to work. Leisure use would be on top of this.
At this location, we would also connect two established and growing communities at Greenwich and Newham - New Charlton and Woolwich in Greenwich and the Royal Docks and Silvertown in Newham, are a vast development area delivering 70,000 new jobs and 55,000 new homes. The GLA is moving to the Crystal Building in the Royal Docks just north of the Barrier and this will also generate foot and cycle traffic.
How do you get to the bridge?
The bridge would have landings at Barrier Park to the north and the gardens to the south so connecting Transport for London (TfL’s) Green Chain (Read More here) south of the river to walks and cycle routes extending up the Lea Valley to Stratford. Cyclists can use the Thames Path Cycle route to access Greenwich Peninsula and Canary Wharf.
How much time would people living in Charlton and Silvertown save by crossing the river via the Thames Barrier Bridge, compared to existing routes?
We have considered a journey from New Charlton on the south to Pontoon Dock Station on the north side using existing means of transport:
- Public Transport: 42 mins (via DLR)
- Walking: 70mins (via foot tunnel)
- Cycling only: 90 minutes (via Tower Bridge)
- Cycling & walking: 30 mins (via Woolwich foot tunnel)
We have considered the same journey by the new Thames Barrier Bridge:
- Walking approximately 15 mins
- Cycling approximately 8 mins
At present, the journey by car between Charlton and Royal Victoria Docks exceeds 35 minutes, but with this link, you could cycle in under 10 minutes, and traffic on current road crossings would ease as a result.
What stage are you at with the Thames Barrier Bridge (TBB) proposal?
There is serious interest in taking the proposal forward. The Thames Barrier Bridge idea is a design concept that is receiving support from local MPs and councillors, residents groups, cycle organisations, developers, environmentalists and transport experts. The feedback we have had from the many stakeholders that we have engaged with so far, is that TBB could provide a great solution to better connect walking and cycling routes in East and South East London.
So far our team is investing their own time in exploring and developing this concept. However, funding needs to be secured and we are looking for local (political) champions, also for investors - initially for a feasibility study, at least.
Have you spoken to key stakeholders such as the Port of London Authority, Transport for London, the Environment Agency & local government?
We have informally been in touch with many of the relevant statutory authorities and other stakeholders and this is an ongoing process. We have had some initial feedback and, overall, people think it is a good idea. With any project on this scale, there are many areas to address and this is the process we are going through currently. For example, a navigation risk assessment will be required, likewise detailed reviews of security and safety issues.
Our team has some experience of building on and over the river so we understand the complexities. Marine engineers Beckett Rankine have designed scores of structures on the Thames and architects Lifschutz Davidson Sandilands were responsible for the Golden Jubilee Bridges at Hungerford Railway Bridge. This is London’s most popular crossing, built next to railway lines and above tube tunnels.
What are the dimensions of the bridge?
Overall the bridge is 530m from bank to bank, the proposed width of the deck is 8.6m, with a 3m pedestrian footway and a 4m cycleway and a physical barrier between the two. The bridge deck provides 15m clearance above Mean High Water Springs tides. The spans are 61m wide with two opening sections of 30m which match the Thames Barrier’s openings.
Will there be separate lanes for pedestrians and cyclists?
Yes, there will be a physical barrier keeping pedestrians and cyclists apart. The deck of the bridge is 8.6m wide overall with a 3m pedestrian footway and a 4m cycleway and a barrier between the two lanes.
Wouldn’t a tunnel be better?
A tunnel would be more expensive and much less suitable for pedestrians and cyclists. There is an existing foot tunnel at Woolwich, which is little used. Cyclists have to dismount and push their bikes through the tunnel and use a lift at each end A cycle/pedestrian bridge like this one are more sustainable in terms of the amount of carbon expended to construct, as tunnels require a large amount of excavation which is also a costly process.
The Silvertown tunnel will provide a route for motor vehicles but not for bikes or pedestrians unless they get onto a bus.
What environmental impact will this bridge have e.g. light pollution effect on wildlife and local communities?
TBB is eminently deliverable, thanks to the way in which it shadows the piers of the Thames Barrier, making it a relatively low-cost, low-impact bridge for pedestrians and cycles.
The principal environmental impact will be shading of the intertidal foreshore at each end of the bridge. This would be mitigated by having a light coloured reflective underside to the bridge deck. The bridge’s lighting will be designed to minimise light spill onto the river and consequently will have minimal effect on the marine ecology.
Lifschutz Davidson Sandilands are collaborating with artist Leo Villareal to create the Illuminated River art project (https://www.lds-uk.com/projects/illuminated-river/), working in consultation with the London Wildlife Trust. This artwork is complete on four bridges with five coming forward in March 2021. It is recognised for its sensitivity towards heritage assets and local ecology. So we believe we have the experience to design this project to have as minimal a footprint on the environment as possible.
How much will TBB cost to build?
We estimate the bridge will cost circa £300m.
The positioning of this bridge, adjacent to the Thames Barrier, means more moderate opening spans are possible, which reduces the cost as less material would be used, especially steel. The design is for a low level bascule bridge, which also reduces cost compared to a high level bridge with long ramps. Of course having opening spans is more expensive than a fixed bridge, but they are relatively short and conventional at c30m. They match the length of the Tower Bridge opening spans and that bridge was completed in 1894, and still opens around 1,000 times a year. Our scheme is cheaper than a tunnel in this location, which involves significant excavation.
Our quantity surveyors, Core Five, have used comparable bridges to arrive at their estimates and their lead surveyor worked on the Millennium Bridge so understands the complexities of the river. Both Lifschutz Davidson Sandilands and Beckett Rankine have significant experience in this field. For example, Lifschutz Davidson Sandilands designed the award-winning Golden Jubilee Bridges (a more complex project next to railway lines and above the Bakerloo/Northern line tubes) and The Royal Victoria Dock Bridge, a 150m long footbridge, spanning one of the largest docks in East London.
To take this design forward, the next stage would be to commission a feasibility study, including an accurate cost plan for the project.
Who will fund the Thames Barrier Bridge?
There is serious interest in taking the proposal forward. We are exploring options for both public and some private investment, the former most likely some kind of green bond which the government is committed to backing for projects of this kind. We believe the time is right for this, especially given the forthcoming Copt 26 conference in Glasgow which the UK is hosting. Likewise there are new ideas for capturing land value, in other words, taking the benefit of the enhancement of housing and commercial values catalysed by the improved transport links. All of these ideas would depend on an institutional owner of the project coming forward, such as the local authorities either side, the GLA/TfL or some other government agency.
Will there be a toll to cross TBB?
We are currently exploring all avenues to secure funding for TBB in order to move forward. Tolls aren’t really consistent the idea of sustainable transport and, from our initial research, would not be popular among pedestrians and cyclists.
How many people are likely to use it and for what purpose?
Our preliminary estimate is that the bridge could be used by 5 million pedestrians per year and over one million cyclists. This is for journeys to work only - leisure use would be in addition. These figures are based on future development opportunities planned for 55,000 new homes and 70,000 new jobs in the Royal Docks, Greenwich, New Charlton and Woolwich areas.
The bridge will also be used for leisure purposes - connecting to the Thames cycle path, the Green Chain Walk, local leisure facilities and the Thames Barrier itself. A more detailed study of demand would be compiled as part of the next stage, ideally working with Transport for London (TfL) who hold much of the data. Both Greenwich Peninsula and Canary Wharf would also become much more accessible.
What about the Thames Clippers service? Doesn’t this connect East and South East London?
Thames Clippers provides an essentially longitudinal service along the river. There is a degree of zig-zagging, but to cross the river at Woolwich involves boarding at Woolwich Arsenal and disembarking at Royal Wharf pier two miles upstream.
Have you thought about security issues and the protection of the Thames Barrier?
As with any bridge or significant piece of urban infrastructure, security does need to be considered. We are confident that we can overcome these, as we did for the Golden Jubilee Bridges. Maintaining the security of the Thames Barrier is vital to meet the requirements of the Environment Agency.
The proposed bridge will be located more than 10m away from the barrier to prevent anyone jumping from the bridge onto the barrier. The edge protection to the bridge will be designed to further deter access over the sides. CCTV would monitor both the bridge and the barrier.
In fact the barrier is much more susceptible to deliberate/accidental impact from a boat than from some kind of missile launched from this pedestrian/cycle bridge. The barrier has been hit over a dozen times, for instance in 1997 a 3,000 tonne dredger collided with it, dumping its load and disabling one of the gates.
The piers of the new bridge could be used to protect the barrier from just such an event, as the piers of the Golden Jubilee Bridges protect the caissons of the Hungerford railway bridge with crushable concrete footings.
What about large ships that pass along the Thames and yachts travelling to Greenwich Yacht Club?
The proposed bridge will have a slightly greater width between piers than the Thames Barrier and there will be no reduction in the size of ship that can pass through the barrier.
Provisionally the bridge deck provides 15m clearance above Mean High Water Spring tides. The level of the deck is a balance between providing easy access for pedestrians and cyclists and frequency of opening. The objective is to set it at a level where it opens relatively rarely, while not being so high as to necessitate overlong access ramps. To set it at a height that requires little or no opening, such as Dartford Crossing (which is over 100m high) would provide a most unsatisfactory experience for pedestrians and cyclists.
An in-depth research exercise will be necessary for to determine the optimum bridge level. In the meantime, as a working assumption, we have used a 15m clearance above Mean High Water Springs for our illustrations of the TBB.
Would people have to wait to cross the bridge when ships/boats are passing along the river? How often?
There are circa 1,400 transits a year through the Thames Barrier by vessels taller than 15m, equating to circa 4 per day (some at night). We would expect some openings to accommodate more than one vessel, especially smaller craft such as yachts. By having relatively short bridge spans - in this case 61m wide, with two lifting arms of circa 30m, to match the Thames Barrier’s openings - the time taken to open, let boats pass, and then close the span would be minimised.
We anticipate making the times when crossing the bridge will be interrupted available in advance, perhaps via an app. Pedestrians and cyclists will have a spectacular view while they wait, watching the majestic arms of the bridge open and close to let river traffic through.
How long would it take to build and how disruptive would it be to river traffic?
The bridge would take approximately 24 months to construct. The works in the river would be phased, so as to always maintain at least two of the barrier openings open for navigation. So no river traffic would be stopped.
What about the disruption caused to local residents during construction?
The majority of the bridge construction will be done from the river using marine plant to minimise disturbance to residents. Noisy activities, such as impact piling, will be restricted to weekday working hours. We estimate that TBB would take 24 months to build.
What about the Silvertown Tunnel and plans for it to better connect East/South East London?
The Silvertown Tunnel will not be available for pedestrians or cyclists, unless they first board a bus. The crossing, as with the existing Blackwall Tunnels, is to be tolled. The objective of the Thames Barrier Bridge is to reduce road congestion and emissions by providing an alternative to transport by car or bus.
The Thames Barrier's life is limited, so why design a bridge which matches the Thames Barrier so closely?
The Thames Barrier Bridge is located next to the Thames Barrier, which is expected to remain operational until 2060-2070 or beyond, depending on the rate of sea level rise and life extension works. Eventually, the barrier is likely to be decommissioned once a second barrier is constructed further downstream, at which point the machinery may be removed. But the structure is likely to remain as other redundant elements in the river have, such as the London Chatham and Dover Railway piers next to Blackfriars Bridge.
Why the need for (and expense of) no less than four lifting sections, when surely a good deal of the river traffic could pass beneath the bridge?
The Thames Barrier has six navigable spans, four main ones and two side ones for small craft. Two of the main spans are for inbound traffic and two for outbound. The need for two main navigable spans in each direction is to enable one of the spans to be closed to navigation when its gate is undergoing maintenance. As there are four main navigable spans on the barrier the Thames Barrier Bridge is shown with four opening spans to match. In practice it is likely that only one would open at a time, or possibly two if an inbound and outbound ship were transiting together.