On Friday 21 June 2019 Heidi Alexander, London’s deputy mayor for transport, announced that Transport for London (TfL) would ‘pause development work’ on the proposed Rotherhithe to Canary Wharf bridge project. The reason given was that the estimated midpoint cost of the scheme had risen to £463m and that the final cost could be over £600m. TfL’s budget for the project was £350m.
Back in November 2017 TfL published a background report on the Rotherhithe to Canary Wharf Crossing which considered the Benefit/Cost Ratios of alternative crossings at this location. The report used a capital cost for an opening bridge of £120-180m, for an immersed tunnel £325-335m and for an ‘enhanced’ ferry £30m. From these figures the report concluded that the opening bridge would, if it came in toward the bottom end of the cost range, provide a BCR greater than that of an enhanced ferry.
When we read this report we felt that the benefits of a ferry option, compared to a bridge, did not seem to have been fully appreciated. In particular the disruption due to passing ships, which require the bridge to be opened, would be very much less for a ferry. We also felt that a ferry could be delivered cheaper than the estimated £30m and that the opening bridge, one of the world’s longest, would cost significantly more than £180m. Following the 2017 public consultation TfL awarded a contract to Atkins for developing designs for the bridge option alone; no further work was to be done to develop the ferry option.
We fully support TfL’s ambition to improve the Rotherhithe crossing, the existing ferry which is designed principally for guests at the Hilton hotel is not really suitable for general public use and is very limited for use by cyclists. However we felt it was unfortunate that only one option was being taken forward for further development; we felt that an enhanced ferry solution should also be worked up so that a more informed cost benefit analysis comparison could be made once the bridge cost estimate was firmed up.
Our colleagues at Thames Clippers, who run the existing ferry service, had similar thoughts; they had been working on a concept design for an all electric, zero emission ferry with cycle-on cycle-off capability that could be used on this route. They believed that a service using three of these vessels could provide all the forecast capacity requirement of a bridge with intervals between sailings of only 4 minutes during peak times with all three ferries in operation. We agreed to work together to develop an enhanced ferry concept design on a self-funded basis so that when TfL’s bridge scheme was put out for its second public consultation a fair cost/benefit comparison could be made.
Key to the design of the scheme was finding a location that worked for a new pier at Rotherhithe. The existing pier, which we designed back in 1990, has served the Double Tree Hilton hotel well but it was never intended as a public pier or one that would serve cyclists. To help us solve the problem we brought in Anthony Carlile who is an architect we have worked with regularly on pier projects.
Various option sketches followed until Anthony suggested that we bring a new pier ashore through the old dry dock that lies at the heart of the hotel. It seemed radical to run the access through a listed structure but, checking the levels showed that it could be made to work. We designed the access to incorporate features to aid interpretation of the dock’s history as part of a Thames shipyard.
Next was the design of the vessels to be used for the ferry service. To meet the government’s zero net carbon target for 2050 they clearly have to be electric powered. Thames Clippers have used Aus Yachts from Brisbane, Australia to design previous vessels and our in-house naval architect exchanged ideas with them to develop the concept design for a double ended catamaran ferry with roll-on roll-off capability and an auto mooring system. The mooring system is critical to achieving a fast turn-around for the vessels.
There are a number of proprietary auto-mooring systems on the market, such as the magnetic system fitted to the new Woolwich ferries. Other manufacturers use vacuum pads or mechanical hooks. However all these systems are relatively complex and require a significant amount of equipment on the berth; we felt that for our small ferries we needed something less complex, lighter and with minimal power demand. To solve the problem we have developed a simple drop arm mooring on the vessels which engages with a cushioned yoke on the indented pontoon berth. The mooring can either be operated from the vessel’s helm position or can be made automatic.
All electric propulsion is less of a challenge; there are now a number of electric Ro-Ro ferries in operation, notably in Norway which introduced the world’s first electric ferry, the Ampere, in 2015. Norway is some way ahead of the UK and has resolved to become zero carbon by 2030, a full 20 years before us!
One additional important benefit of our ferry scheme is that we see it as a demonstration project for the furtherance of zero emission transport on the Thames. In the short term there are a several other locations downstream where there is a need for river crossings, such as on the east side of the Isle of Dogs and at Barking Riverside, where a similar ferry operation could usefully be deployed.