The class 47 locomotives were replaced by the class 56s in 1977 with an increase of the number of wagons in a train, in most cases to around 30 to 34. This was followed by the class 58s and the class 60s. Two of the class 60s were named in honour of the men behind the MGR system, 60092 Reginald Munns and 60093 Jack Stirk. A small number of other locomotives were modified for working MGRs. In Scotland the class 26 and some class 20s and in South Wales some class 37s.