December 2025

The late Michael Plunkett was an architect by profession, and one of the pioneer bus preservationists.His particular interests included the Thames Valley Traction Company. Amongst the items in the Trust’s archives is a collection of Michael’s original artwork, many being in pen and chalk on brown sugar paper’
In this example, Michael has illustrated a feature of the war-time operation of buses – in this case Thames Valley single decker 258, but it is the strange looking trailer that it is towing that is of interest.

At that time, Britain had to import its fuel oil, as the North Sea sources had not been developed then. The tankers bringing the oil across the oceans were liable to attack by the U-boats, and a way had to be found to economise on the use of petrol. The solution was to create ‘producer gas’ – a mixture of carbon monoxide, hydrogen and nitrogen - by passing air and steam over hot anthracite (coke), the gas then being fed to the vehicle engine. The plan was introduced in May 1942, and the aim was for 10% of the large company bus fleets to be powered by this method, with the coke being heated in the trailer (a couple of buses had the equipment built into the back of the bus). The scheme lasted until 1944, with the Bristol chassis works being one of the larger makers of the trailers.

No doubt that modern Health and Safety culture would not allow the workman to stand like this whilst he prodded the hot coke, but the priority was keeping the service taking workers to munitions factories and other locations of national importance operating, staff being expected to use common sense rather than follow a set of rules!

MPC/DWG/016
Archive Item of the Month, Dec 2025