"they moved Mk 3 Shackletons (the nose wheel variety) into the old T3 hangers at St Mawgan SIDEWAYS on a set of rails: "
Both Mk 2 and Mk3.
Shortly after arriving at St Mawgan to join my first Squadron, in early '65, I found myself a member of a Board of Enquiry into an upcock involving a Mk 2. Must have been 42 Sqn., as we (206) and 201 had Mk 3s.
Running on the rails were low metal platforms called skates. With these outside the hangar, and held the right distance apart by a long rod, the aircraft was towed backwards onto the skates, and the brakes set. The tailwheel was then swung through 90 degrees, the tractor hitched to the skate nearest the hangar, and the whole thing was moved inside. Tailwheel was then straightened, tractor hitched to main gear leg, (not enough room to hitch it to the tailwheel tow bar), and the a/c was pulled off the skates. As it rolled down the very slight slope of the skates, the airman in the cockpit had to operate the brakes to stop it. Either the airman did not hear the shout for brakes, or there was not enough pressure. The prop of no. 3 engine hit the back of the tractor, bent, and stopped an inch from the tractor steering wheel. Tractor driver bailed out just in time, or it would have been an inquest.