NER Class R

The NER Class R (later, LNER Class D20) was a class of 4-4-0 steam locomotive, designed by Wilson Worsdell for the North Eastern Railway. They passed to the London and North Eastern Railway (LNER) in 1923. In 1936, some were rebuilt with long-travel piston valves and classified D20/2. The unrebuilt locomotives were re-classified D20/1.

NER Class R LNER Class D20
1907-built class R 2387, at Gateshead in 1954
Power type	Steam
Designer	Wilson Worsdell
Builder	NER Gateshead
Build date	1899-1907
Total production	60
Configuration	4-4-0
Gauge
Leading wheel diameter	4 ft 0 in (1.219 m)
Driver diameter	6 ft 10 in (2.083 m)
Wheelbase	23 ft 9 in (7.24 m) engine 12 ft 8 in (3.86 m) tender 45 ft 10+3⁄4 in (13.989 m) total
Axle load	19.8 long tons (20.1 t; 22.2 short tons)
Locomotive weight	D20/1: 54.1 long tons (55.0 t; 60.6 short tons) D20/2: 55.45 long tons (56.34 t; 62.10 short tons)
Tender weight	41.2 long tons (41.9 t; 46.1 short tons)
Locomotive and tender combined weight	D20/1: 95.3 long tons (96.8 t) D20/1: 96.65 long tons (98.20 t; 108.25 short tons)
Fuel type	Coal
Boiler	4 ft 9 in (1.45 m) diameter
Boiler pressure	200 psi (1.4 MPa) later reduced to 160 psi (1.1 MPa)
Fire grate area	20 sq ft (1.9 m2)
Heating surface: Tubes	638.7 sq ft (59.34 m2)
Heating surface: Flues	292 sq ft (27.1 m2)
Heating surface: Firebox	139 sq ft (12.9 m2)
Heating surface: Total	1,318.7 sq ft (122.51 m2)
Superheater area	204 sq ft (19.0 m2)
Cylinders	two inside
Cylinder size	19 in × 26 in (483 mm × 660 mm)
Valve gear	Stephenson
Tractive effort	17,025 lbf (75.73 kN) later reduced to 15,567 lbf (69.25 kN)
Power class	BR: 2P
Retired	1943-1957
Disposition	All scrapped

References

• Ian Allan ABC of British Railways Locomotives, part 4 (1948 ed.). p. 19.

Other websites

• D20/1 Archived 2016-12-20 at the Wayback Machine Rail UK
• D20/2 Archived 2016-12-20 at the Wayback Machine Rail UK
• The W.Worsdell Class D20 (NER Class R) 4-4-0 Locomotives LNER Encyclopedia