They were the last steam cranes built at their Reddish works before the Crane Division was transferred to Herbert Morris & Co of Loughborough. The crane entered service in 1931 and, numbered MP9 was based at Newton Heath engine shed near Manchester.  At this time, the LMS railway began to build larger and heavier express locomotives. By 1938, it was considered desirable that some of the 36-ton cranes be uprated to 50-ton capacity to ensure adequate lifting capacity was available should the need arise.  The two Craven cranes were returned to their makers to have the necessary modifications made to increase their lifting capacity.

MP9 moved to Willesden in London during the early days of the Second World War. It was renumbered RS1015/50 in 1941; the other Craven crane, MP8, becoming RS1013/50.  Like other cranes situated at strategic points throughout the railway network, they were considered an important resource for clearance or reconstruction work during the war.  It is known that both Craven cranes were requisitioned to assist with the installation of the heavy gun batteries on the south coast, hurriedly constructed to protect against the risk of invasion following the fall of France in 1940.

Although the realities of War were over by the summer of 1945, it wasn’t long before RS1015/50 was used to assist with the clearance of equally grim railway accidents.  That at Bourne End, near Hemel Hempstead, in September 1945 saw 43 people lose their lives, while seven years later, in October 1952, the Willesden crane helped clear up the collision at Harrow and Wealdstone.  There were as many as 112 fatalities here, and RS1015/50 was employed during the latter stages when it replaced RS1013/50 used in the initial phase.