NER Class S2

The North Eastern Railway Class S2 - London and North Eastern Railway Class B15 - was a mixed-traffic 4-6-0 steam locomotive designed by Vincent Raven. The design was based on NER Class S.

NER Class S2 LNER Class B15
Type and origin Power type Steam Designer Vincent Raven Build date 1911-1913 Total produced 20
Specifications Configuration: ​  • Whyte 4-6-0 Leading dia. 3 ft 7+1⁄4 in (1.099 m) Driver dia. 6 ft 1+1⁄4 in (1.861 m) Wheelbase 26 ft 0+1⁄2 in (7.938 m) engine 12 ft 8 in (3.86 m) tender 50 ft 8+1⁄4 in (15.450 m) total Axle load 19.4 long tons (19.7 t) Loco weight 71.1 long tons (72.2 t) Tender weight 44 long tons (45 t) Total weight 115.1 long tons (116.9 t) Firebox: ​  • Grate area 23 sq ft (2.1 m2) Boiler 5 ft 6 in (1.68 m) Boiler pressure 175 psi (1.21 MPa) Heating surface: ​  • Firebox 140 sq ft (13 m2)  • Tubes 723 sq ft (67.2 m2)  • Flues 506 sq ft (47.0 m2)  • Total surface 1,730 sq ft (161 m2) Superheater: ​  • Heating area 361 sq ft (33.5 m2) Cylinders 2, outside Cylinder size 20 in × 26 in (510 mm × 660 mm) Valve gear Stephenson
Performance figures Tractive effort 21,115 lbf (93.92 kN)
Career Operators North Eastern Railway, London and North Eastern Railway Numbers NER: 782, 786-788, 791, 795-799, 813, 815, 817, 819-825 LNER (1946): 1691-1698 Withdrawn 1937-1947 Disposition All scrapped

Superheaters

The first seven were built with saturated (non-superheated) boilers, however the remaining thirteen were fitted with Robinson 24-element superheaters. The saturated B15s were eventually fitted with superheaters. Some of these rebuilds used Schmidt superheaters, however they were eventually converted to use Robinson superheaters, as Robinson superheaters were the LNER’s standard type of superheaters.

Stumpf Uniflow variant

The last of the class, No.825 was fitted with Stumpf Uniflow cylinders. The inlet and exhaust ports were separate. Although the exhaust port was always the same size, the inlet port could vary in size according to the position of the cutoff. In 1918, the system was used on C7 No.2212, with a tidier result. Due to the special attention required for these experimental locomotives, in March 1924, the locomotive was rebuilt as a standard B15, matching the other members.

Performance

Although they were used on their suitable work, they steamed poorly if handled with crew who wasn’t used to the B15s (which also affected the B13s), and thus they were unpopular with crew who didn’t have enough experience on the B15s.

Accidents and incidents

• On 14 February 1920, locomotive No. 787 was hauling a freight train which was involved in a head-on collision with a freight train hauled by locomotive No. 788 at Skelton, Yorkshire.^[1]

Withdrawal

Withdrawal commenced with No.788 in September 1937, and all were gone by December 1947, with the last being No.1696 (NER No.820). None were preserved.^[2]