20020 & 20106 approach Scropton on 12 August 1989 with the 16:11 Derby to Crewe service. For a few weeks in 1989 pairs of 20s were used on this service due to a shortage of Class 150 units. As the stock was Mk 1 coaches without any air conditioning, and it was summer therefore in theory no heating was required, Class 20s were ideally suited for these trains, given that at the time there were some surplus locos, due to their replacement on various freight duties by Type 5 power.