On 11th July 1936, No. 2004 left the Doncaster Plant and entered traffic. Named Mons Meg the locomotive immediately began running in from Doncaster shed. On several occasions the locomotive was seen hauling trains from King’s Cross including the heavy 600 ton 16.00 departure to Doncaster.
Mons Meg is seen leaving the ‘Cross – Ken Nunn NRM / SSPL
Gaining the Doncaster Works number 1839 and boiler No. 8789 the locomotive was identical to its sister engine 2003 except for one subtle difference. In an attempt to reduce the ferocious blast from the locomotive exhaust and the detrimental effect of pulling the fire to hard that resulted, a by-pass valve was fitted to divert part of the exhaust steam away from the blastpipe. Originally a butterfly valve was fitted and this was opened by pulling a mechanical linkage that ran along the left hand side of the locomotive behind the vacuum ejector pipe. However oil often carbonised in the valve and it would get stuck open or closed, causing the locomotive to be failed. The draughtsman who designed the valve, L. Parker, was sent to unstick and sort the valve out at Thornton and eventually came up with a new design. In July 1937 it was changed to a plug type valve, pulled to open and pushed to shut, again using a mechanical linkage. However it was noted that its use was ignored by drivers as it could make the locomotive steam badly on uphill stretches of line. Parker was once again sent North and after riding on the locomotive found the mechanical linkages seized due to lack of use. A redesign was required and in June 1939 it was replaced by an automatic valve working off a linkage on the reverser which opened when cut-off was 38% or longer in fore gear. Problems with carbonisation still occurred requiring frequent dismantling and cleaning during maintenance periods. More proposals were put forward during 1940 including an automatic flap-valve and a steam operated vale. Neither option was ever taken past the design stage.
No. 2004 has her coal trimmed at King’s Cross – Ken Nunn NRM / SSPL
When outshopped new No. 2004 was painted in full LNER apple green livery. During a heavy repair at Cowlairs in February 1943 the locomotive was painted in plain wartime black livery. Other wartime modifications included having its valences removed and top lamp bracket lowered. The latter was carried out on all the streamlined P2’s to aid opening the smokebox door to replace boiler tubes. When the lamp iron was in the original position it struck the chime whistle restricting the opening of the door and causing problems withdrawing the top rows of tubes.
Mons Meg was always allocated to Haymarket shed and completed 294,243 miles in as built condition. However like the rest of the class it was to be rebuilt as a Pacific and was withdrawn on 22nd August 1944 and returned to Doncaster for conversion. The engine returned to traffic in the November of the same year receiving boiler No. 8771 which had previously been carried on Cock o’ The North. The locomotive was sent to Haymarket shed and returned to service. In June 1946 the locomotive was renumbered 504. After the locomotive’s next repaint on 12th March 1948, carrying apple green with ‘BRITISH RAILWAYS’ written on the tender side, the locomotive received the number E504, the E denoting the Eastern Region were responsible for its maintenance. However this was to last only 11 days with the engine renumbered 60504 on 23rd of the same month.
Rebuilt as a pacific and briefly numbered E504, Mons Meg is seen at the ‘Plant’ – NRM / SSPL
In late 1949 new homes were being found for the A2/2 class. Three were transferred to York and three to New England shed in Peterborough. Mons Meg was transferred to New England on 9th January 1950. In November 1953 the engine underwent another heavy overhaul and received boiler number 29771 which had previously been carried by No. 60501. Like all the A2/2 class locomotives No. 2004 required regular trips to the works with no less than 32 visits to the workshops between converting to a Pacific and withdrawal. The end for the locomotive came on 23rd January 1961 when the locomotive was finally withdrawn and scrapped at Doncaster.
In need of some attention, No. 60504 climbs away from King’s Cross – P2SLC Collection