Another vehicle known to have been used by Y Service is the dear old Humber Heavy. Could that have handled the trailer? Trouble is a lot of the information concerning Interceptor and D/F were, and still are higly classified. The men who used the equipment developed the techniques still used today. They also used WC54, mainly with the Special Liasion Units that took the information from Bletchley and rebroadcast, in cipher of course, to Allied Headquarters.