47508 S.S. Great Britain passes Lyneham on 7 May 1987 with the 1B46 17:00 Paddington to Hereford service. The following week this train went over to HST operation. It was a 50/50 chance whether trains on the Cotswold Line were Class 47 or 50 hauled at this time. I preferred 50s at the time, but with hindsight either was acceptable!