This brilliant boat owes its existence to a unique combination of owner, designer and builder whose vision, talents and capabilities are outstanding.
The Thames Clipper service on London's mighty river has been refined and developed in tune with the times and environmental expectations such that it provides a first rate and very popular public transport service. While Earth Clipper's predecessors have been impressively successful, the new series of ferries is even more environmentally friendly.
They are all aluminium, shallow draught, high-efficiency, hybrid fast craft. Under twin diesel engines, the new ferries can reach 28 knots but, on battery power alone, they can easily, quietly, smoothly and emission-free, make 12 knots. They can easily be converted to hydrogen power when that becomes readily available. Meanwhile, as aluminium catamarans, they are among the safest ferries afloat.
"The vessel combines the latest solutions in energy storage and hybrid propulsion, whilst also servicing the requirements of a high-volume passenger transport client, in line with the stringent regulation for UK High-Speed Passenger Craft," James Mozden, Principal Naval Architect at Wight Shipyard, told Baird Maritime.
"It is the first zero-emission, large (220-pax) high-speed hybrid electric ferry in the UK," added One2Three Naval Architects Managing Director Steve Quigley, "and it is providing valuable data as an example to feedback into both new designs, and also how it may transition to increased electrical energy as shoreside infrastructure catches up."
For Quigley, the weight and capacity of the drivetrain and the supporting energy storage systems on board is key for any vessel attempting to operate on low energy-dense fuels, and this poses a challenge for Earth Clipper as this technology develops.
"Many lessons were learned, but a key one was early integration with suppliers not familiar with the marine industry, educating crew and operations side of the business, as to the most efficient method of driving and maximising the vessel's capabilities. Operations and maintenance are a very different experience compared to a conventional diesel-propelled vessel."
The integration of all the major machinery componentry onboard represented another challenge that needed to be overcome, particularly in ensuring the battery management system communicated seamlessly with the power management system, with the hybrid power system, and the conventional drive system.
"This demanded very close collaboration between all parties involved," said Wight Shiyard Project Engineer Charlie McCallum. "As being one of the very first vessels to implement this kind of technology on a commercial scale, there was little to no precedent on the engineering design."
In Mozden's view, the marine industry is heavily focused at the moment on carbon emissions reduction.
"Hybrid systems, batteries, and alternative fuels are all being regularly discussed and investigated, he said. "As shipbuilders, we face the challenge of identifying the best way of bringing these concepts to market. Regulation is constantly evolving in response to the vessels and the technologies that are being developed, and so it's vital that our designs not only meet the regulations of today but are capable of adapting to future requirements placed on our operators."
The same trends towards low-emission propulsion alternatives are also having an impact on the naval architecture industry.
"Staying abreast of innovation means being able to commercialise, adapt to changing certification rules, and leveraging products from suppliers at the design stage before they are officially released to market," Quigley told Baird Maritime. "It is now an everyday task, not only in terms of current vessel requirements but also future-proofing to enable today's vessels to adapt many years down the line."
Quigley added that having less energy-dense fuels translates into maximising energy efficiency in vessels. Hence, efforts in hull shape development and optimisation of every design for minimum energy usage also need to be considered in every design decision.
Commenting about the state of the passenger vessel industry, Quigley said that many discerning operators are interested in reducing their fossil fuel and carbon footprints, hence the consideration of combinations of electric, hydrogen, and alternative fuels, with the favoured energy source differing depending on the local supply chains and available infrastructure.
"Earth Clipper is a perfect example of a hybrid solution that has zero-emission output within the central London emissions zone, but also capable of high-speed operations at 30 knots outside the zone, providing fast transport to the further downstream regions of the Thames."
For Sebastian Rowe, Wight Shipyard Commercial Manager, the passenger vessel industry remains highly fluid.
"There's lots of technical innovation, mostly in a drive towards greater efficiency and lowering of carbon footprint. By that same token, I would say that the powering and propulsion market will be where the greatest development will occur. It is hard to foresee exactly how this will evolve, but I think in the short term, we'll see an increased use of electrification, particularly lithium battery systems, where appropriate and feasible, accompanied by development in the necessary shore-side infrastructure needed to support.
"Longer term, I think greater emphasis will be directed towards the development of solid-state battery technology, owing to its inherently greater energy density and serviceable lifespan compared with lithium-ion, to a point where it can feasibly be considered for the commercial marine market."
Rowe added that, in the case of the British workboat industry as a whole, it remains strong thanks to high-quality construction and effort in getting the fundamentals right.
"From a client's perspective, they want to know that they can rely on the shipyard to deliver a vessel to them on time, built to a high standard and according to the requirements they have laid out. In many ways, our export success just goes to add credence to this; we've had numerous international clients that could've feasibly had their vessels built in-country, but instead came to us because they were confident that we could deliver their project according to their expectations. I think if UK shipyards can offer that kind of core value, there will always be a place in the market for that."
Rowe said Wight Shipyard is going from strength-to-strength at the moment. The period during and after Covid were particularly difficult for the company and the wider industry as a whole, but since then, there has been a significant uptick in opportunity and growth that the team is managing to capitalise on.
"It has demanded steady management and a dedicated team within the business," he told Baird Maritime. "Certainly, in terms of the domestic UK market, we're leading the field in lightweight, high-speed commercial craft. Even overseas, our clients are aware about what we're able to achieve and the direct benefits that can be imparted on their operations."
