I was on good terms at one time with several Heavylift crew members, certainly at the beginning of the operation, they IL-76s were strictly call out for oil spill and crew training. The crews were accommodated in some very large caravans near Duxford. Mobile home sized beasts, but just how mobile I’m not sure.
perhaps later in the contract the CAA became more flexible? I honestly don’t know.
I worked in Heavylift Ops at the time the IL76 and An124's came on the scene. Certainly the IL76 (and Pelita Hercules) were on oil spill standby in the early days. Indeed, the IL76 crew complained about recency and we organised some training circuits at Stansted. I went along, but after two or three touch and go's the tower said the noise complaint phone line was ringing off the wall, and could we stop. After a while both the Herc and the IL76 were released to operate charters. We also had an AirStan IL76 we used.
The Herc crew were billeted at the Flint Cross Hotel near Duxford. The Russians lived in an old manor house near Bishops Stortford, plus some accommodation in Saffron Walden. I don't remember any crews living in caravans.
Also late lamented Heavylift had their logo on a couple of AN-124s for a spell. The IL-76s that wore Heavylift colours were dedicated to Oil Spill support work and not available for commercial use.
I believe photos exist of Heavylift AN-124s
Heavylift Volga Dnepr (it was a joint venture) had about eight AN214's on our ops board.