The vehicles will be used to carry pelletised biomass from the Port of Tyne, near Newcastle in northeast England to Drax Power Station near York, Britain's largest coal-fired power station which is being converted to burn biomass.

The wagon, which was designed by Lloyds Register Rail and built by WH Davis, has a tare weight of 30 tonnes and is capable of carrying a 71.6-tonne payload with a total capacity of 116 cubic metres. Work began on two prototypes in January and Drax says designers faced a particular challenge developing a vehicle which could be accommodated within the tight limits of W6a loading gauge, which allows operation over most of the British mainline network.

The wagon features a stainless steel bodyshell with aluminium roof doors and a patented product flow system for unloading.

Drax has ordered 200 of the wagons from WH Davis as part of a £700m investment in Drax power station, which includes boiler modifications and new biomass reception, storage and handling facilities. The facility began burning biomass in April and two further generating units will be converted by 2016. Each will burn around 2.3 million tonnes of biomass per year.