They are tried and tested, the tri-mode trains, and they will be used on the Rhymney line from 2023. They use a mix of diesel power, overhead electric and also battery power. In terms of battery power, huge strides are being made in terms of the development of new lighter, smaller batteries, and I think, whilst there is some disagreement amongst experts at the moment, there is recognition that, as technology advances, the weight of battery units in trains and in cars will go on falling and, therefore, those units and vehicles will become more efficient and be able to cope with more passengers as well.

The whole point of our procurement exercise was that it was mode-agnostic. We were driven by the objectives, and the objective was to ensure that we could deliver as many services as frequently as possible, carrying as many people as possible, and the market assessed what would be best for each and every line, and determined that on the Rhymney line a tri-mode solution was the most appropriate.