How do you think the Dutch Van provided the steam ?
It had to have Power from a Generator that was originally located on top of one of the Water Tanks..
This caused a lot of problems so they relocated it between the two 1,000 Pound Swirley Flow Boilers....
They did not become Gen Vans Till they were Modified for the MK 2a,s.....
Then they had two Generators......
One Cummins which provided Power and Electric Heat when required.....
The small one a Lister, which supplied lighting and Control only, I think?