The British loco destroyed in the tests was a Sulzer powered Class 46 1-Co-Co-1 and the wagon was an FNA nuclear Flask wagon. The rest of the wagon fleet are still in action today (I should know, I manage the depot where they are maintained) and we still have a gap in the numbering scheme where FNA 550019 used to be. Rumour at the time was that the locomotive had every bolt holding the Sulzer engine in loosened off in Derby Works and left on the last threads so that the thing would fly apart on impact! KEV