|
B12 4-6-0 - 61572
.jpg)
(Photo: Steve Allen)
Click here for
the B12 Boiler Appeal page. Help B12 return to steam
History
History of B12
class
With increasing traffic at the beginning of the 20th Century,
the Great Eastern Railway (GER) found it needed a series of locomotives which
were more powerful than the existing K, but with a light axle loading and a short
wheelbase suitable for the GER lines. These latter restrictions resulted in
S.D. Holden's design being notably smaller than most British 4-6-0s.
Officially designated Class S69 by the GER, they quickly became known as the
"1500" Class after the first locomotive built. The LNER would give them the
classification of B12, and would find the combination of low axle loading and
short wheelbase very useful attributes.
As an evolution of the Claud Hamilton design, the driving
wheels were reduced from 7ft to 6ft 6in diameter, and the boiler was increased
to the limits of the locomotive's dimensions. The cylinders were kept in an
internal position, but were increased in size to 20x28in. The Belpaire firebox
was located over the middle driving axle. A large cab was fitted. This in
combination with the GER standard tender, resulted in a locomotive which
looked larger than it really was. The large cab resulted in an 8ft distance
between the firebox door and the tender, requiring the fireman to use a
long-handled shovel.
Although design work started in 1908, construction of the
first B12 would not start until 1911. The GER built a total of 70 B12s in
eight batches before Grouping. This does not include No. 1506 which was
destroyed in a collision at Colchester on 12th July 1913, only seven months
after construction. A replacement was built (No. 1535).
No. 1504 was built with a 1.5in side traverse on the trailing
coupled axleboxes, allowing increased flexibility on curved track. This had
been tried experimentally on "Decapod" 0-10-0T in 1902, and would be adopted
as a standard feature on the B12s. Nos. 1500-3 were altered accordingly.
Initial allocations of the B12s were to haul expresses on the
GER line to Colchester and Norwich. As more locomotives were built, they
started to work all of the GER express services to London including the
Cambridge services.
In the late 1920s, increasing train weights and poor quality
fuel, led to a desperate need for additional power for express passenger
services in the GER District. Previously planned Gresley K2 2-6-0 engines
helped, and a three-cylinder 4-6-0 design was in preparation (this would
become the B17 'Sandringham' Class). However, a stop-gap was needed and a
final batch of ten B12s were ordered. These differed from the originals with
the addition of Lentz oscillating cam poppet valve gear, no decorative framing
over the driving wheels, and the smokeboxes were slightly longer. The rear
axleboxes were not fitted with the side traverse facility. These would be
given the classification of B12/2.
During the mid-1920s, the LNER performed a series of B12
bridge tests on the former Great North of Scotland (GNSR) lines, due to an
urgent need for greater power. Although the tests were successful, the GER's
shortage was critical and transfers to the GNSR district did not take place
until 1931 when the GER's shortage had been relieved. Transfers continued over
the next ten years, resulting in 31 B12s allocated to Scotland by 1942.
Initially these Scottish B12s were allocated passenger services between Elgin
and Aberdeen. They were later also used on the coastal Elgin line, the Buchan
section, and the Deeside line; and also operated goods and fish services The
Scottish B12s would continue to work the heaviest of these services until the
arrival of the Thompson B1s in 1947.
More |
