NZR X class

Specifications
Specifications
Configuration:;
• Whyte	4-8-2
Gauge	3 ft 6 in (1,067 mm)
Driver dia.	45 in (1.143 m)
Length	56 ft 9.75 in (17.32 m)
Adhesive weight	46.7 long tons (47.4 t; 52.3 short tons) (original); 45.6 long tons (46.3 t; 51.1 short tons) (rebuild)
Loco weight	66.7 long tons (67.8 t; 74.7 short tons) (original) ; 66.6 long tons (67.7 t; 74.6 short tons) (rebuild)
Tender weight	27.3 long tons (27.7 t; 30.6 short tons) (original) ; 28.55 long tons (29.01 t; 31.98 short tons) (rebuild)
Total weight	94.0 long tons (95.5 t; 105.3 short tons) (original) ; 95.15 long tons (96.68 t; 106.57 short tons) (rebuild)
Fuel type	Coal
Fuel capacity	4.0 long tons (4.1 t; 4.5 short tons) (original); 5.0 long tons (5.1 t; 5.6 short tons) (rebuild)
Water cap.	2,200 imp gal (10,000 L; 2,600 US gal)
Firebox:
• Grate area	37.1 square feet (3.4 m2) (original); 37.5 square feet (3.5 m2) (rebuild)
Boiler pressure	230 psi (1,586 kPa) (original); 215 psi (1,482 kPa) (rebuild)
Heating surface	2,066 sq ft (191.9 m2) (original); 1,185 sq ft (110.1 m2) (rebuild)
Superheater:;
• Heating area	None (original); 168 square feet (15.6 m2) (rebuild)
Cylinders	2 high pressure + 2 low pressure (original); 4 high pressure (rebuild)
High-pressure cylinder	13.5 in × 22 in (343 mm × 559 mm)
Low-pressure cylinder	22 in × 22 in (559 mm × 559 mm)

Type and origin
Type and origin
Power type	Steam
Builder	NZR Addington Workshops
Build date	1908 - 1909, 1913 - 1915 ; 1943 - 1949 (rebuild)

NZR X class
NZR X class
	X class 588, photographed leaving Petone Workshops circa 1913. Godber Collection, Alexander Turnbull Library.
Power type
Type and origin
Power type	Steam
Builder	NZR Addington Workshops
Build date	1908 - 1909, 1913 - 1915 ; 1943 - 1949 (rebuild)
Configuration:;
Specifications
Configuration:;
• Whyte	4-8-2
Gauge	3 ft 6 in (1,067 mm)
Driver dia.	45 in (1.143 m)
Length	56 ft 9.75 in (17.32 m)
Adhesive weight	46.7 long tons (47.4 t; 52.3 short tons) (original); 45.6 long tons (46.3 t; 51.1 short tons) (rebuild)
Loco weight	66.7 long tons (67.8 t; 74.7 short tons) (original) ; 66.6 long tons (67.7 t; 74.6 short tons) (rebuild)
Tender weight	27.3 long tons (27.7 t; 30.6 short tons) (original) ; 28.55 long tons (29.01 t; 31.98 short tons) (rebuild)
Total weight	94.0 long tons (95.5 t; 105.3 short tons) (original) ; 95.15 long tons (96.68 t; 106.57 short tons) (rebuild)
Fuel type	Coal
Fuel capacity	4.0 long tons (4.1 t; 4.5 short tons) (original); 5.0 long tons (5.1 t; 5.6 short tons) (rebuild)
Water cap.	2,200 imp gal (10,000 L; 2,600 US gal)
Firebox:
• Grate area	37.1 square feet (3.4 m2) (original); 37.5 square feet (3.5 m2) (rebuild)
Boiler pressure	230 psi (1,586 kPa) (original); 215 psi (1,482 kPa) (rebuild)
Heating surface	2,066 sq ft (191.9 m2) (original); 1,185 sq ft (110.1 m2) (rebuild)
Superheater:;
• Heating area	None (original); 168 square feet (15.6 m2) (rebuild)
Cylinders	2 high pressure + 2 low pressure (original); 4 high pressure (rebuild)
High-pressure cylinder	13.5 in × 22 in (343 mm × 559 mm)
Low-pressure cylinder	22 in × 22 in (559 mm × 559 mm)
Maximum speed
Performance figures
Maximum speed	30 mph (48 km/h)
Tractive effort	26,620 lbf (118.4 kN) (original) (31,150 lbf (138.6 kN) starting); 29,500 lbf (131 kN) (rebuild)
Number in class
Career
Number in class	18
Numbers	439–446 ; 588–597
Locale	North Island Main Trunk
First run	1909
Last run	1957
Retired	1935–1957
Current owner	Feilding & Districts Steam Rail Society (1)
Disposition	One preserved, remainder scrapped

The New Zealand X class was a pioneering class of eighteen 4-8-2 steam locomotives built for New Zealand Railways Department (NZR) and designed by A. L. Beattie that operated on the national rail network of New Zealand. In 1908, a heavy and powerful locomotive was required to haul traffic on the newly completed mountainous central section of the North Island Main Trunk Railway, and as a logical progression of the 4-6-2 Q class design, the 4-8-2 wheel arrangement was created for the X class.