NZR N class

NZR N class
NZR N class in service for the Wellington and Manawatu Railway Company as number 9, c. 1900.
Type and origin Power type Steam Builder Baldwin Locomotive Works Build date 1885, 1891, 1901
Specifications Configuration: ​  • Whyte 2-6-2 Gauge 3 ft 6 in (1,067 mm) Driver dia. 49.125 in (1.248 m) Length 50 ft 2 in (15.29 m) (1891 batch) Adhesive weight 21 long tons (21 t; 24 short tons) Loco weight 31.8 long tons (32.3 t; 35.6 short tons) Tender weight 19.0 long tons (19.3 t; 21.3 short tons) Total weight 50.7 long tons (51.5 t; 56.8 short tons) (1891 batch) Fuel type Coal Fuel capacity 7.5 long tons (7.6 t; 8.4 short tons) Water cap 5,000 imp gal (23,000 l; 6,000 US gal) Firebox:  • Firegrate area 16 sq ft (1.5 m2) Boiler pressure 135 psi (931 kPa) (1891 batch) Heating surface 853 sq ft (79.2 m2) Cylinder size 15 in × 20 in (381 mm × 508 mm)
Performance figures Maximum speed 103.6 km/h (64.4 mph) Tractive effort 9,890 lbf (43.99 kN)
Career Operators Wellington and Manawatu Railway (2), New Zealand Government Railways (10) Number in class 12 Numbers 27, 30, 34, 36, 37, 42, 351-354, 453 (ex WMR No. 9), 454 (ex WMR No. 10) Locale Auckland, Hawke's Bay, Wellington (both NZR and WMR lines), Wairarapa, West Coast Retired November 1926 - March 1934 Current owner Wellington and Manawatu Railway Trust Disposition Withdrawn, one preserved

The N class were 12 steam locomotives that operated on the national rail network of New Zealand. They were built in three batches, including one batch of two engines for the private Wellington and Manawatu Railway Company, the WMR, by the Baldwin Locomotive Works in 1885, 1891, and 1901. Previously the N class designation had been applied between 1877 and 1879 to Lady Mordaunt, a member of the B class of 1874.

Despite the Long Depression of the 1880s, the young New Zealand railway network continued to expand and additional motive power was required. The New Zealand Railways Department had normally ordered locomotives from England up until this time, though it had previously bought locomotives from United States manufacturers (such as the Rogers K class), and in 1885 it placed an order with Baldwin, whose first New Zealand locomotives were the T class, to construct the six original members of the N class, which entered service between October and December 1885.

Six years later the WMR required additional motive power to handle the growing traffic on their line from Wellington to Longburn, just south of Palmerston North. Its typical supplier of equipment was Baldwin, who offered the WMR a locomotive similar to the N class. The WMR ordered two such locomotives and they entered service as Nos. 9 and 10. They proved to be more efficient than the 1885 batch, and in an attempt to match these efficiencies the government converted N 27 into a Vauclain compound, but with little success.

In 1901, the government ordered four similar locomotives.