 The Midland Region also had favourable reports , but a marked consistency in losing time on the longer runs between Holyhead and Euston was recorded , although all complaints were down to the individual techniques of the operating crews . This was compounded by the irregular allocation of the class to depots all over the network , meaning that few crews ever had a great deal of experience in driving them . The Southern Region also had an allocation of seven in May 1953 , when all Merchant Navy Class locomotives were temporarily withdrawn for inspection after 35020 " Bibby Line " sheared a crank axle on the central driving wheel . 
