NZR UD class

NZR UD class

Type and origin Power type Steam Builder Baldwin Locomotive Works Build date 1904 Total produced 2

Specifications Configuration 4-6-0 Gauge 3 ft 6 in (1,067 mm) Driver diameter 58 in (1,473 mm) Adhesive weight 29.2 long tons (29.7 t; 32.7 short tons) Loco weight 39.5 long tons (40.1 t; 44.2 short tons) Tender weight 27.4 long tons (27.8 t; 30.7 short tons) Fuel type Coal Water cap 2,400 imp gal (11,000 L; 2,900 US gal) Tender cap 5 long tons (5.1 t; 5.6 short tons) Boiler pressure 185 psi (1,276 kPa) Firegrate area 16.5 sq ft (1.53 m2) Heating surface 1,095 sq ft (101.7 m2) Cylinders 2 Cylinder size 16.5 in × 22 in (419 mm × 559 mm) Valve gear Stephenson

Performance figures Tractive effort 15,280 lbf (68.0 kN)

Career Number in class 2 Retired 1929

The NZR UD class was a class of two 4-6-0 steam locomotives built by the Baldwin Locomotive Works in 1904 for the Wellington and Manawatu Railway Company. Two locomotives were built.

Specification

Weighing 39.5 long tons (40.1 t; 44.2 short tons) with a tender of 27.4 long tons (27.8 t; 30.7 short tons), they could haul express trains easily at 50 miles per hour (80 km/h) in suitable parts of the country. With huge (for the period) 58 inches (1,473 mm) coupled driving wheels, a working steam pressure of 185 pounds per square inch (1,276 kPa), and 16.5 inches (419 mm) diameter cylinders with 22 inches (559 mm) piston strokes, the handsome "Ud"s were more than capable of making up lost time with mile-a-minute runs as recalled with pride by old Manawatu railway employees.

Withdrawal

However, fast and powerful as they were the "Ud"s were unable to survive the standardisation program between 1925 and 1935 and were written off in 1929.