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B12 4-6-0 - 61572
(Photo: Ben Boggis)
History
History of B12
class-cont
During the 1920s, many of the B12s participated in Gresley's
Feed Water Heater experiments. These attempted to recover waste heat by using
the exhaust steam to pre-heat the water before it entered the boiler. In 1926,
No. 8509 was fitted with a Worthington-Simpson feed pump and heater, but this
was removed in 1929. From 1927, 55 B12s were fitted with ACFI (Societe
l'Auxiliaire des Chemins de Fer et de l'Industrie) feed water heating
apparatus. This apparatus was mounted above the boiler, and consisted of two
heater drums and a single steam cylinder which operated two water pump
cylinders. The first of these drew water from the tender into one of the drums
where it mixed with exhaust steam. The heated water flowed into the second
drum, where the second pump drew it into the boiler. All three cylinders were
double acting. The ACFI apparatus was removed when B12s were rebuilt with
larger boilers to B12/3, between 1934 and 1941. Maintenance costs of the ACFI
apparatus were found to be higher than the savings in fuel. One of the main
problems was that the system tended to scale up and required acid cleaning
every six weeks. This cleaning in turn tended to damage pipe joints. The
Scottish B12s used softer water and did not suffer this scaling problem. These
would be the last to have their ACFI apparatus removed, in 1941.
Between 1932 and 1944, all ten B12/2 locomotives and 44 of the
original B12/1s were rebuilt with larger diameter boilers and long-travel
Stephenson piston valves. The Belpaire fireboxes were replaced with
round-topped fireboxes. These were given the classification of B12/3.
The GNSR District continued to have limited axle loadings, so
the GNSR allocated B12s could not be rebuilt with the larger diameter boilers.
Hence between 1943 and 1948, nine B12/1s would be fitted with new boilers of
the original smaller size but with round-topped fireboxes, and given the
classification B12/4. This new boiler was to current LNER standards, and was
shared with the J20 0-6-0 locomotives.
During World War 2, the GER district B12s were often called
upon to haul some extremely heavy loads. Age and wartime maintenance led to
them not being in the best of condition, but they were still capable of
hauling 480-490 ton trains when required, even if it was a struggle. After
D-Day, a number of the B12/3s were allocated to American ambulance trains.
Their restricted loading gauge, light axle loading, and short wheelbase
allowed them to run across most Britain's railway network, although they
mainly worked in South West England.
Excluding No. 1506 which was destroyed in the Colchester
accident in 1913, the first withdrawal was No. 8534 in 1945. This was one of
the remaining B12/1 Belpaire firebox locomotives, and all of these B12/1s
would be withdrawn by 1954. The B12/4 locomotives were withdrawn between 1948
and 1953, with their boilers being sent to Stratford for use on the surviving
J20s.
The large-boilered B12/3s would survive the longest. These
were withdrawn between 1947 and 1961, with the last B12s hauling services
between Norwich and Cromer, and occasional visits to Liverpool Street. From
1959, No. 61572 became the sole surviving B12. As well as regularly hauling
the Yarmouth to March parcels train, it also hauled an increasing number of
rail tours. Withdrawn in September 1961, No. 61572 has been preserved.
Text used with kind permission of Richard Marsden and his
online
LNER
Encyclopedia.
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