Introduced: 1888

Number in Class: 2

Ob Class Register

Locomotive Specifications

Builder:   Baldwin Locomotive Works, Philadelphia, USA

Engine Weight:     38.5 tons	Tender Weight:    19.1 tons	Total Weight:    57.6 tons	Adhesive Weight:     34.3 tons
Length over Buffers:     51' 3"	Total Wheelbase:    43' 3½"	Engine Wheelbase:    18' 11"	Coupled Wheelbase:     12' 3"
Tender Wheelbase:     12' 10"	Driver Wheel Dia.:    43"	Cylinders HP:     Two - 16" x 20"	Cylinders LP:
Grate Area:    16.5 sq ft	Evaporative Area:     1013 sq ft	Superheated Area:	Working Pressure:     165 psig
Tractive Effort:     15717 lbs f	Coal Capacity:    3.5 tons	Oil Capacity:	Water Capacity:     1500 gals

Remarks:     In 1887 the Wellington and Manawatu Railway Company decided to import some large locomotives of the "Consolidation" type for service on the heavily graded section between Wellington and Paekakariki. Two engines were obtained originally taking up the road numbers 9 and 10, but in 1892 were renumbered 11 and 12. When the W&MRC was taken over by the NZR in 1908, they became Class 'Ob', Nos. 455 and 456. Like all Americam locomotives imported to New Zealand before 1901, these 2-8-0s had Stephenson link motion. An unusual feature was the Le Chatelier counter-pressure brake which they were provided. Despite their small driving wheels, they were no sluggards on the level and performed well.