Wrightbus revealed the latest stage of its hydrogen coach development at the Cenex Expo 2024 at Millbrook proving ground in Bedfordshire today and yesterday.

The low carbon vehicle show hosted the first public outing of this demonstrator. Not only is the vehicle significant in being the company’s first hydrogen coach it has worked on, but also because it is the first coach it has developed since the ‘90s. B&CB went to the Expo to see the vehicle in the metal earlier today (5 September 2024).

Perhaps the first thing to notice about the hydrogen coach demonstrator is the fact it is not a coach, but a bus. Nevertheless, its hydrogen driveline is configured to power a coach, despite it being used on a GB Kite Hydroliner. It is important to remember that this vehicle is about demonstrating the capabilities of the powertrain. The bodywork will come later.

George Foster, Principle Software Engineer at Wrightbus, told B&CB that the demonstrator vehicle uses a Voith heavy duty motor. This is a common choice for the manufacturer, having been selected for many of its existing buses. George said: “Voith have one of the most efficient systems on the market.”

In particular, the demonstrator has the Voith Electric Drive System (VEDS) for PCV applications installed. This is rated at 310kW of continuous power, with a torque of 3,100Nm. George said that those that know this driveline in Wrightbus’ existing products will be familiar with the way the demonstrator drives.

In the rear of the saloon, walled off by a plastic see-thorough screen, are six 15kWh Forsee Power Pulse 15 batteries, providing total power of 90kWh for the vehicle.

For fuel cells, Wrightbus is using four StackPack 75 units from Symbio, a French provider. “We haven’t used them before, so we are trialling their product,” George said.

In terms of where the drive systems are to be located on the finished coach, George said that many of the company’s designs currently mount them on the underfloor, but it is possible they could end up on the roof, which is the case for the hydrogen tanks on the demonstrator. The importance of maximising luggage capacity will be taken into account by Wrightbus when it comes to fitting equipment below decks, B&CB is told.

George stressed it is important to remember the layout of the driveline and fuel stacks in the demonstrator is not necessarily representative of the configuration of the final coach. He said: “There are various configurations we have drawn up.”

Nor is Wrightbus wedded to the choice of equipment providers it has used on the demonstrator. The final product could use other manufacturers’ equipment.

On trial

The vehicle is set to go out on test runs following the Expo, which will last up to the end of this year. The testing is expected to help Wrightbus develop where the various components will fit. The first of these trials will be with Translink, seeing the vehicle shadow a diesel coach on route 212 between Londonderry and Belfast. Following this service will be a real challenge for the vehicle, according to George, with some demanding inclines to negotiate. “If it’s capable of surviving that route, then it can do anything,” said Head of Research and Data Analytics at Wrightbus, Andy Harris.

There will be no passengers on this on-road trial, George says, but the vehicle will be loaded with ballast to simulate their weight.

The intercity coach sector is one of the markets Wrightbus foresees its hydrogen coach entering, according to George: “But really, we want to aim it for any market that would want it.”

On why hydrogen coaches seem to be less forthcoming in their development in the market than hydrogen buses have been, George said: “It’s more technically demanding. The high-power components required make it more expensive to do. How it is all packaged together is also a challenge.”

He also notes hydrogen infrastructure is still levelling up to the point it needs to be to support the role out of more hydrogen vehicles.

The development of the coach has been supported by the Advanced Propulsion Centre (APC), an organisation dedicated to accelerating the transition to a net-zero automotive industry.

Bodywork

Andy Harris said the company has applied a lot of what was learnt in its existing hydrogen city buses for the development of the coach. Looking at the amount of miles operated by diesel coaches in a day, he does not believe a battery electric option is viable. The goal

currently is to test it to see if it can achieve a range of 1,000km (622miles).

The demonstrator displayed today can be considered phase one of Wrightbus’ move into hydrogen coach development, Andy said. It is intended to prove the powertrain behind the vehicle.

In addition to the driveline, work is being done on developing the body of the coach. Andy says that as well as a single-decker, a double-deck variant of the hydrogen coach could also be produced. “We have identified a niche market there,” he said. Design work for both variants is underway.

Andy said the hope is for the bodywork to be done in-house, but it will be exploring all options, including working with bodybuilders.

Currently, Wrightbus is exploring the use of a more traditional aluminium body for the coach rather than any composite material other electric vehicles have adopted, Andy explains. The company will also be making use of its in-house GRP facilities for the vehicle, as it does for its city buses.

The emphasis on the coach body design will be on achieving a light weight vehicle, while still delivering a quality product, according to Andy.

In terms of delivering a finished vehicle, Andy estimates two to three years. This somewhat aligns with what Wrightbus CEO, Jean-Marc Gales, said earlier this year that a hydrogen coach would be in production by 2026.

As well as single- and double-deck variants, different lengths and powertrain configurations could also be offered. Andy said: “A lot of work will go into how we can maximise the seats, with a lot of emphasis being put into the costs and the supply chain. We will be looking at maximising the space in the roof and engine bay without encroaching too much on the passenger space.”

It is not just Wrightbus putting some thought into the vehicle’s design. The company’s suppliers have also been challenged with potentially supplying the parts needed for the vehicle.

As well as Translink, various large UK operators have also shown interest in the possibility of operating a hydrogen coach, according to Andy.

As the coach is designed, Robert Best, Director of Engineering at Wrightbus, notes that the hydrogen supply network will only continue to develop.

For Robert, hydrogen is ‘absolutely the right fuel to use’ for this project. However, he notes that if there is enough interest in a BEV platform for a coach, then the company would not rule out designing one.

“It’s about using the right fuel for the right customer,” he said.