Left to right: Sean Collins (Uber Boat by Thames Clippers) and Peter Morton (Wight Shipyard Co) in the structure of Uber Boat by Thames Clippers’ hybrid catamaran (source: Christopher Ison)
The technology and design behind the river Thames ferry operator’s new hybrid ferries – and how hydrogen is likely the next step
Uber Boat by Thames Clippers chief executive and co-founder Sean Collins has revealed how the hybrid ferries the Thames River operator is building are a “major step forwards towards net zero”.
He told the press gathered at Wight Shipyard Co for an exclusive look at the company’s catamarans being built there, the “key element today is their green potential and how much they are greening our fleet–it is a major step forwards towards net zero.”
Indeed, he explains the high-speed river operator’s plan is to only build a boat that can be used beyond 2025, and to develop its fleet up until 2040 to achieve a net-zero position.
The important role the two new hybrid catamarans–with options for a third–will play in this ambition is they will run entirely on batteries in Uber Boat by Thames Clippers’ central zone, from Tower Bridge to Battersea, the rest of the time running on hydrotreated vegetable oil (HVO).
They are the first of their kind–the UK’s first hybrid high-speed passenger ferries. There were major considerations when it came to preparing for the vessels, which have been planned for a while.
Mr Collins expands, “We were ready to start building these boats, and then Covid caused a pause and in some respects it was a benefit as it gave us longer to look at their development. Through that process, we were asking a lot of questions in dialogue with Design One2three and Wight Shipyard, to look at what application goes with what batteries and what engines, and what best aligns among those suppliers.”
He singles out a key challenge: keeping a lid on a boat that is increasing in weight due to the additional technical equipment. As they added a significant amount of weight, the boats were made longer to meet safety and damage stability requirements. It was a mixed bag to make everything work.
But dialogue with Wight, One2three Naval Architects and others involved with previous applications meant the right selection was made. Also, a major benefit was Wight Shipyard has recently built a hybrid electric windfarm vessel, giving plenty of valuable experience that could be applied to Uber Boat by Thames Clippers’ catamarans.
MAN Energy Solutions’ engines were chosen – the same ones Uber Boat by Thames Clippers used for the refit of its oldest 200-pasenger ferry Hurricane, five years ago. “We were able to see the benefits and efficiencies of these through the refit on Hurricane. In that case, because of the SCR system, we had to reduce passenger numbers by 18 as we did not start from scratch. We trialled the engine on that boat, giving us confidence we had made a significant change by refitting the boat with new engines.”
The engines will be fuelled with HVO, sourced from a UK supply. Mr Collins says, “It’s the only alternative to diesel that engine manufacturers support at this stage. We have been using it on four of our vessels for the last year.”
HVO, he says, has reduced NOx and SOx by 70%.
Battery benefits
The batteries, provided by Spear Power Systems, will be charged by both the engines and onshore power. Mr Collins says, “We invested in our homeport, Trinity Wharf and the timing was perfect as there has been a complete redevelopment of hundreds of homes around there and the power has been upgraded. We upgraded through building another pier and facility, so all our vessels use shore power. There is no generator use when the vessels are alongside and that will complement the battery charging. “Due to the style of our operations, with the short turnarounds at either end, it was imperative we didn’t rely on shore power to ensure continued operational capability of the vessels and we don’t want the engines cutting in on the part of the journey where the vessels run entirely on battery.”
Therefore, it will be important to use both shore and engine power to charge the batteries. Wight Shipyard chief executive Peter Morton explains it further, “The power from the engine is used for propulsion power or to charge the batteries. In the early part of the day, they will power the propulsion, and none will go to the battery as they have had overnight charging. But as the day goes on and the overnight charge drops down, some of the propulsion will need to be diverted to charging the batteries. So, the more charge overnight, the less fuel you burn.”
In terms of planning and dealing with challenges, a reason there is six months between delivery of the first and second newbuilds is it gives Uber Boat by Thames Clippers time to trial the catamarans and iron out any potential problems.
Mr Collins says the advances in the new vessels are not just within the battery technology but also in other areas. He emphasises, “These technological advances are not just within the mechanics, we cannot lose sight of that. An efficient and effective hull design with a superstructure weight as minimal as possible while meeting the rigidity and strength it needs to be safe are significantly important and something that has been achieved well in our three previous newbuilds in Wight shipyard, where we manged to achieve weight savings, which was key.
“Strong tides and some piers located in positions where you need quite a lot of power to navigate in and out were all taken into consideration when designing the vessel. Working with 123 Naval Architects and Wight, we continue to break new ground in weight and hull efficiency.”
Asked by PST about how the shipyard balanced out the heavier weight of these vessels due to the battery technology versus trying to keep it as light as possible, Mr Morton says, “Through design. Weight is crucial–if you save 10% weight, you save 10% fuel. We worked very hard on that.”
He emphasises, “People underestimate how important weight saving is. We can justify the extra cost of the boat with fuel savings.”
He singles out building the catamarans out of aluminium is important. He says, “The average piece of aluminium gets used eight times, we are finding more and more people are moving towards aluminium; it is fully recyclable, and it is not just about reducing emissions but increasing recyclability.”
Moving towards hydrogen
Uber Boat by Thames Clippers’ plans go even further – it is investigating using green hydrogen fuel cells, not just in newbuilds but also potentially for these hybrid battery catamarans, rather than HVO in the future.
Mr Collins expands, “We are looking at the potential for using hydrogen fuel cells or any other renewable energy source that may suit our application and are in dialogue with class and flag state. We would be delighted to eventually convert these boats to hydrogen fuel operation. This is our vision, but it will very much depend on supply availability.”
The ferry operator is working on several projects focused on alternative fuels, including one which is looking at running on 100% batteries, while the Clipper 2.0 project is predominantly focused on green hydrogen and hydrogen fuel cells. The company is also looking at potential fuel facilities, where these would be located and what Uber Boat Thames Clippers’ fuel demands would be, as well as how to effectively deliver a fuelling process equal to what the company currently has with diesel.
Mr Collins says, “We can’t have boats spending half their time on the quay charging or refuelling as this requires labour and would be eating into the working day.”
Asked by PST about a timeline for using hydrogen, he says, “Beyond 2025, we are working towards that. But it is very dependent on whether there is availability. We would do it now if we could, which is why we are thinking of the design and build of the boats in terms of how they can be retrofitted.”
Wight Shipyard is working with Uber Boat by Thames Clippers, Shell and the National Grid on the HOST project looking at how to bring green hydrogen to the vessels. Mr Morton adds, “It needs joined-up thinking. Hydrogen is perfectly possible for a boat, as is fully electric, but without the infrastructure it won’t happen. It is all very well authorities saying we’ve got to reduce carbon emissions, but unless there is the infrastructure to support it, you can’t charge or can’t refuel.”
Mr Collins sums up, “Technological development important to us in releasing future environmental visions. These two boats cost us £11.5M (US$14.1M) and that is a significant increase from the previous boat, purely because of technical development. Moving forward, we are looking at even higher costs which will be a challenge, but we are committed to continuing on the path to net zero and we’ve got to work with everyone to ensure we can make it as economical as possible.”
