New South Wales D57 class locomotive

New South Wales D57 class

Class D57 Locomotive

Type and origin Power type Steam Builder Clyde Engineering, Granville Build date 1929-1930 Total produced 25

Specifications Configuration 4-8-2 UIC class 2'D1'h3 Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Driver dia. 5 ft 0 in (1.524 m) Axle load 23 ton Adhesive weight 201,600 lb (91,400 kg) Loco weight 310,710.4 lb (140,935.9 kg) Fuel type Coal Fuel capacity 14 tons Water cap 9000 gallons Firebox:  • Firegrate area 65 sq ft (6.0 m2) Boiler pressure 200 psi (1,379 kPa) Heating surface 3,390 sq ft (315 m2) Superheater: ​  • Heating area 775 sq ft (72.0 m2) Cylinders 3 Cylinder size 23.25 in × 28 in (591 mm × 711 mm) Valve gear Gresley conjugated

Performance figures Maximum speed 50 mph (80 km/h) Tractive effort 64,327 lbf (286.1 kN) Factor of adh. 3.82

Career Operators New South Wales Government Railways Class D57 Numbers 5701–5725 Nicknames Lazy Lizzies Withdrawn 1957–1961 Disposition 1 preserved, 24 scrapped

The D57 class was a class of 4-8-2 steam locomotives built by Clyde Engineering for the New South Wales Government Railways in Australia. The tenders were built by Mort's Dock.

The locomotives were among the heaviest of locomotives in Australia with a 23-long-ton (23.4 t; 25.8-short-ton) axle load and this along with their width restricted their sphere of operation to Thirroul on the Illawarra line, Wallerawang on the Main Western line and Junee on the Main South line.

They were not permitted to operate on the Main Northern line due to load limitations on some bridges and a tighter loading gauge. They had the highest tractive effort of any conventional engines used in Australia and were of approximately equal capability to the 60 class Garratt locomotives. They were very reliable and had the nickname Lazy Lizzies because they made heavy workings seem effortless. Another nickname was bestowed on the class, Chuckling Charlies due to their syncopated exhaust beat.

The three cylinder design fitted to the class gave it a distinctive off-beat exhaust sound when climbing upgrade. This design was also fitted to the 58 class. However, a couple of features, such as the Gresley conjugating valve gear fitted to these locomotives has been the source of debate as to its efficiency. A further 13 were built to a similar design in 1950 as the 58 class.