I'm obliged to an anonymous reader for the link to this video of the re-enactment of a World War I steam-powered convoy. Its YouTube page explains it as follows:
The Great Dorset Steam Fair WW1 commemorative convoy from Bovington Camp to Tarrant Hinton, on 16th August 2014, arrives at the roundabout in front of the Bryanston School Gates - just before Blandford Bridge. A vintage (Ford?) staff car forms the escort at the front. McLaren road locomotive 1332, Gigantic, then appears hauling the 72 ton Pickfords trailer bearing the 1914 WWI Holt 75 HP gun tractor, 'Ben'. The strain of turning the Pickfords trailer through ninety degrees gives Gigantic cause to slow down and then bounce forward with accompanying chuffs as the driver expertly brings the trailer around. McLaren road locomotive 1652, Boadicea, pushes from the rear making up the 80 foot train. Burrell road locomotive 3257, Clinker, follows bringing troops. Roger, son of the late Fred Dibnah, is (I believe) at the controls of the 1917 Foden steam lorry that follows. Roger is co-owner of the Holt tractor. Show co-founder, Ronald Harris is with his 1915 Daimler lorry which was army owned in the war. The rear is brought up by the 1918 GMC water bowser owned by Rowley Moors of Bridport.
After a stop for sandwiches at the Crown Hotel you will see the lead driver check that all are ready, a blast of the whistles to signal the start and then the convoy setting off for the final leg of the journey. Please comment with any further information / corrections and don't forget to tick on 'Like' if you enjoyed this video. I was lucky with the shots/light and think that I caught the vehicles at their active best - especially the early sequence showing Gigantic being turned around the roundabout. All credit to those who have restored these vehicles and who handled them so well. It was a truly spectacular and memorable event.
Watch the video in full-screen mode for the best results.
A memorable event indeed! Wish I'd been there to enjoy it in person.