The Thompson B2 4-6-0s
On Thompson's succession to
Gresley in 1941, he quickly initiated a wide-ranging
standardisation plan. His initial plans for 4-6-0 locomotives was to introduce his
Class B 4-6-0 (later Class B1), keep the
B16 (then being rebuilt), and to also keep the
B12 as a special case due to their light axle loading.
This plan was amended to include rebuilds of the B7 and B17 classes.
The B7s would never be rebuilt, but ten members of the three-cylinder
B17 'Sandringham' Class would be rebuilt as two-cylinder
In 1942, initial plans for these rebuilds kept the
appearance but increased the boiler pressure to 220psi. Rebuilds did not start until 1945, by which time the cylinders
had been repositioned slightly. This resulted in the bogie moving forward by 5in.
The boiler pressure was raised slightly to 225psi and was of the Diagram 100A type from the
Thompson B1 design. This was developed from the original B17, so
it made a good standardised choice.
No. 2871 Manchester City was the first to be rebuilt, due to it entering Darlington Works in need of major
repair after a connecting rod failure in November 1944.
Rebuilding would be delayed due to higher priority
O7 'Austerity' rebuilds, resulting in No. 2871
not re-entering service until August 1945. Eight more B17s would be rebuilt before
Nationalisation in 1948, and a tenth B17 was rebuilt in 1949.
No. 2871 kept its original 4,200 gallon tender, but the other locomotives had their Great Eastern (GER) type tenders
replaced with larger tenders from other locomotives. Two (Nos. 2815 & 1632) received the old tenders from
the two withdrawn P1 Mineral Mikado locomotives,
whilst the others received tenders from withdrawn
C7 4-4-2 locomotives.
When No. 2871 Manchester City re-entered service, it participated in a number trials against
B17/1 No. 2827 Aske Hall. These trials showed a 10 percent improvement in
efficiency over the B17 due to the increased boiler pressure. The riding was said to be hard
but without the usual oscillations which the B17s were known for.
In 1947, further trials compared a B17/6 (with a Diagram 100A boiler) and a Thompson B2.
These showed that the B17/6 ran more efficiently and was freer running when compared to
a standard B17. Indeed, it was even deemed slightly superior to the Thompson B2 with
coal and water economy of 6 percent and 10 percent greater power.
By this time, the wisdom of rebuilding B17s as B2s was questionable.
The Thompson B1 fitted the LNER's mixed traffic needs better.
With the fitting of Diagram 100A boilers to the remaining B17s, the B2's advantage of having
a higher boiler pressure was removed. Also, the Thompson B1 met the LNER's mixed traffic
needs much better than the B2. Hence, no further rebuilds were authorised.
The B2s worked passenger services in the GER district, typically into Liverpool Street.
From 1956, all of the B2s were based at Cambridge and worked all the main line services from Cambridge, sometimes
venturing as far as Sheffield and Manchester.
Withdrawal of the Thompson B2s started in 1958, and was completed in 1959.
Tender details are for the LNER tenders. The B2s were also fitted with NER tenders and
||10in piston valves
||344 sq.ft. (24x 1.344in)
||1033 sq.ft. (121x 2.25in)
||460 sq.ft. (24x 1.244in)
||(@ 85% pressure)
||125 tons 10cwt
||73 tons 10cwt
||52 tons 0cwt
|Max. Axle Load:
||18 tons 12cwt
The last Thompson
B2s were withdrawn in 1959, and none survived into preservation.
Langley Models sell an N gauge kit of the B2.
DMR sell kits of the B2 for both OO gauge (4mm scale) and O guage (7mm scale).
Most of the B2s were rebuilt at about the same time as the 1946
Thompson renumbering, hence they had a mixture of
pre-1946 and post-1946 numbers when rebuilt. No. 2844 was actually rebuilt after Nationalisation and was given its
BR number (61644) at the same time as the rebuild.
No. 1671 (BR No. 61671) was renamed Royal Sovereign in April 1946. Following its withdrawal in September 1958,
No. 61632 was renamed Royal Sovereign in October of the same year. These locomotives were the official
Royal engines during the periods that they bore this name.