The Hill J20 (GER Class D81) 0-6-0 Locomotives
Hill's Class D81 (LNER J20) is usually considered the ultimate in
traditional Great Eastern Railway (GER) goods engine design. The GER already had forty two
ROD 2-8-0 (LNER O4) locomotives on loan from the
Government working on the Cambridge line.
It was expected that this line would see considerable increases in goods traffic in the immediate post-War period,
and the J20 was built to meet this need.
Following GER practice, the boiler and motion were borrowed from an existing passenger design. In this case,
the B12 4-6-0 provided the boiler, cylinders, valve gear,
pistons, and connecting rods. With a boiler pressure of 180psi and a tractive effort of 29,044lb, the J20 was
the most powerful 0-6-0 design in the UK until the
Bulleid Southern Railway Q1 'Austerity' was introduced in 1942.
A total of twenty five J20s were built at Stratford in three batches between 1920 and 1922.
The use of the B12 4-6-0 boiler and motion resulted in a
long wheelbase of 18ft 10in. Despite this long wheelbase, the J20s could still traverse curves of 4 chains radius
- the same as the preceding
J16, J17, J18, & J19 locomotives.
The LNER eventually replaced the J20's spring-loaded side control trailing axleboxes with plain trailing boxes.
This had the effect of restricting the J20s to curves of radius 5 chains or larger.
In 1925, No. 8280 was experimentally fitted with
Lentz oscillating-cam poppet valve gear.
This was the first
application of Lentz valve gear in the UK, and
was simply an experiment to collect data on steam distribution
and coal consumption. The trial was deemed a success, and the
Lentz valve gear was fitted to a number of
LNER types, starting with the B12s.
No. 8280 reverted back to conventional piston valves in September 1937.
In 1941, new boilers were required for the J20s and the un-rebuilt
B12 4-6-0s. The opportunity was taken to redesign the
boiler to meet contemporary LNER practice. The new boiler replaced the original Belpaire firebox with a round topped
firebox. There were minor variations in boiler dimensions, but the GE-pattern superheater was retained.
The J20s were re-boilered with the new boilers starting in 1943, and were classed as J20/1.
Eight J20s still had their original Belpaire fireboxes at Nationalisation (1948), but these had all been
re-boilered by 1956.
Most of the J20s were allocated to Cambridge and March, but individual engines often had short allocations to
Colchester, Norwich, Lowestoft and King's Lynn. Stratford was also usually noted as having a couple of J20s.
The J20s were usually used on the heavy coal trains between Whitemoor and Temple Mills. They continued operating
these duties after the introduction of the larger
O2 2-8-0s to East Anglia in 1932.
Although all of the J20s were fitted with vacuum ejectors, they were rarely used on passenger services until the
1930s. During the 1930s, the J20s were occasionally used on heavy cross-country excursion traffic to the coast.
Cambridge also often used J20s for passenger services in an emergency.
After World War 2, the introduction of further 2-8-0s including
O7 'Austerities', displaced the J20s from the main line to
cross country duties.
The allocation during January 1959, was to: Stratford (11), March (10), and Cambridge (4).
Rapid withdrawals started later in 1959. The last four J20s were withdrawn from March in September 1962.
||201.6 sq.ft. (21x1.1in)
||1099.5 sq.ft. (187x 1.75in)
||366.1 sq.ft. (21x 5.25in)
||(@ 85% boiler pressure)
||93 tons 0cwt
||54 tons 15cwt
||38 tons 5cwt
|Max. Axle Load:
||18 tons 16cwt
None of the J20s survived into preservation.
4mm scale kits of the J20 are sold by PDK, Crownline, and McGowan.
Thank you to the Mike Morant Collection for the photograph of No. 64685 at Stratford.