This NR6117 : Peat Drying. is likely to commercial peat cutting, I'd hazard a guess for one of the Campbeltown distilleries - are there still two working? It's been a while since I was down that way. There used to be similar sights by the A9 from Latheron to Thurso. I had a look at the photos around that route, but saw no sign, maybe it doesn't happen any more - been a while since I was up that way, too. Must get out more!