After the closure of the Stainmore line a 'freight only' branch survived extending from Appleby to Warcop and then past Kirkby Stephen as far as Hartley Quarries. Hartley was an important intermediate source of revenue for the railway. The quarries were developed in the early 1920's and a rail connection was provided along with a new signal box - Merrygill - in 1925. Much of the output from Hartley was transported to the North East.
During the years of full production Hartley Quarry certainly made its presence felt on the local district. Every weekday lunch time there would be heavy blasting, preceded by a klaxon to warn that charges were about to be detonated. Outgoing loads would be marshalled at Kirkby Stephen and incoming empties would await the 'pilot' handling local freight movements.
When the closure proposal was announced local quarry owners were some of the leading figures from the Kirkby Stephen area in terms of organising objections at the TUCC hearings.
After the closure of the main line the two tracks were severed about 220 yards north of Merrygill Viaduct too allow a head shunt for trains accessing the quarry and and buffer stops installed. For the next six years there was a frequent 'quarry working' along the section of line that now serves as a very popular local footpath to collect loads and return empties. This train used a Carlisle (Kingmoor) steam locomotive and worked down the Settle to Carlisle line to Appleby then onto the branch via Warcop. These trains also provided a local freight service to Warcop and a siding at the former east yard at Kirkby Stephen, where the freight consisted mainly of coal for the 'drops'.
About 1967 - just after the picture on the left was taken - it was judged too risky to allow locomotives off British Rail 'metals' and onto the quarry's own system even with extreme caution because of the danger of the locomotive falling through the ageing track. At some stage that autumn the last steam hauled Hartley trains were run and Type 2 or Type 3 diesels from Carlisle took over the service. Other local freight services were also withdrawn in that year.
The final train up to Hartley ran on 31 October 1975
Ivatt 4MT 43120 carefully extracts a load from the quarry siding in 1966
Ivatt 4MT 43028 enters the Hartley Quarry sput to collect a load. 'Empties' are standing on the main line outside the signal cabin