New South Wales Z27 class locomotive

New South Wales Z27 class
Class Z27 Locomotive
Type and origin Power type Steam Builder Hunslet Engine Company Build date 1913 Total produced 8
Specifications Configuration: ​  • Whyte 2-6-0  • UIC 1′Cn Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Driver dia. 4 ft 0+1⁄2 in (1,232 mm) Length 54 ft 4+7⁄8 in (16.58 m) Axle load 12 long tons 15 cwt (28,600 lb or 13 t) Adhesive weight 36 long tons 8 cwt (81,500 lb or 37 t) Loco weight 45 long tons 2 cwt (101,000 lb or 45.8 t) Total weight 80 long tons 7 cwt (180,000 lb or 81.6 t) Fuel type Coal Fuel capacity New: 5 long tons 10 cwt (12,300 lb or 5.6 t) Water cap. New: 2,150 imperial gallons (9,800 L; 2,580 US gal) Firebox: ​  • Grate area 21 sq ft (2.0 m2) Boiler pressure New: 160 psi (1.10 MPa), Dec. 1921: 150 psi (1.03 MPa) Heating surface 1,240 sq ft (115 m2) Superheater None Cylinders Two, outside Cylinder size 18 in × 24 in (457 mm × 610 mm) Valve gear Walschaerts Valve type Slide valves
Performance figures Tractive effort New: 20,660 lbf (91.9 kN), Dec. 1921: 19,240 lbf (85.6 kN) Factor of adh. New: 3.97, Dec. 1921: 4.24
Career Operators New South Wales Public Works Department New South Wales Government Railways Class G1204, Z27 from 1924 Numbers PWD1-PWD8, 1204–1211, (2701–2708 from 1924) Retired 1957–1966 Disposition 1 preserved, 7 scrapped

The Z27 class (formerly G.1204 class) was a class of steam locomotives built by Hunslet Engine Company for the New South Wales Government Railways of Australia.^[1][2][3]

Eight 'Mogul' type locomotives were built in 1913 for the New South Wales Public Works Department as railway construction locomotives, working on lines such as Coffs Harbour to Glenreagh, Glenreagh to Dorrigo and the Tumbarumba railway line between Humula and Tumbarumba.^[4]

When the New South Wales Government Railways assumed responsibility for railway construction in 1917, these locomotives were transferred and became the (G)1204 class. These locomotives were considered too modern to be utilised on construction work and were transferred to more demanding duties. However they were found to be unsuitable for working lines which abounded in curves, having a tendency to shed their valve motion on anything other than the straightest of track. They were transferred to Narrabri West where they stayed for practically the whole of their remaining lives, working to Moree, Pokataroo, Walgett, Mungindi and Boggabilla.

The first two withdrawals occurred in 1957, a further four followed in 1963.