NER Class O LNER Class G5
Ex-NER 0-4-4T in Stratford Locomotive Shed yard, 1946.
Type and origin Power type Steam Designer Wilson Worsdell Build date 1894-1901 Total produced 110
Specifications Configuration: ​  • Whyte 0-4-4T Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 5 ft 1.25 in (1.556 m) Loco weight 54.2 long tons (55.1 t) Fuel type coal Boiler pressure 160 psi (1,100 kPa) Cylinders two inside Cylinder size 18 in × 24 in (460 mm × 610 mm)
Performance figures Tractive effort 17,265 lbf (76.80 kN)
Career Withdrawn 1950-1958 Disposition All original locomotives scrapped. One replica being constructed.

The NER Class O (LNER Class G5) was a class of 0-4-4T steam locomotives of the North Eastern Railway,^[1][2] designed by the company's Chief Engineer, Wilson Worsdell.^[2] They all survived into British Railways ownership in 1948 and their BR numbers were 67240-67349. They were withdrawn between 1950 and 1958.

In July 1957, locomotive No. 67338 was used for a series of tests into the performance of concrete sleepers when trains were derailed. These tests took place between Halifax and Keighley, Yorkshire.^[3]

None of the G5s were preserved, although a replica, No. 1759 is under construction at Shildon.^[4] It will be built for use on various heritage lines.

Bachmann Branchline have made a OO gauge model of the NER O class.