It could have been on its belly on a cradle… cradle bearer collapses, coil shot forward and out the side of the trailer… This would happen if there were no bore restraints on it… These are Ali coils, the same as the one that was lost, although the picture is a few years old…
The same thing happened to one of ours when were were at home, up on the nescliffe by pass… only strapped over the top…