NZR WAB class

NZR WAB class
WAB 794 on its first excursion after restoration, with the Capital Connection rolling stock. Photo by Joseph Christianson
Power type	Steam
Builder	NZR Addington Workshops, Christchurch (1+1) NZR Hillside Workshops, Dunedin (12+8) A & G Price Limited, Thames (3+5)
Build date	1939
Configuration	4-6-4T
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Wheel diameter	54 in (1.37 m)
Wheelbase	33 ft 1 in (10.1 m)
Length	44 ft 5 in (13.5 m)
Weight on drivers	42.0 long tons (42.7 t)
Locomotive weight	71.5 long tons (72.6 t)
Fuel type	Coal
Fuel capacity	3.0 long tons (3.0 t)
Water capacity	1,700 imp gal (7,700 L)
Boiler pressure	200 psi (1,400 kPa)
Firegrate area	33.0 sq ft (3.07 m2)
Heating surface: Total	1,146 sq ft (106.5 m2)
Superheater area	277 sq ft (25.7 m2)
Cylinders	Two
Cylinder size	18 in (46 cm) bore 26 in (66 cm) stroke
Top speed	60 mph (97 km/h)
Power output	1,000 bhp (750 kW)
Tractive effort	22,260 lbf (99.0 kN)
Number in class	30 (16 WAB+14 WS)
Number	687 - 798
Locale	All of New Zealand
First run	1918 - 1926
Retired	1967 - 1972
Scrapped	1969 - 1972
Current owner	Feilding and District Steam Rail Society (1)
Disposition	Withdrawn, 2 preserved

The W^AB class locomotives were steam locomotives designed, built and used by New Zealand Railways Department. Their wheel arrangement is described by the Whyte notation 4-6-4T. The locomotives were designed by NZR chief draughtsman S.H. Jenkinson as tank versions of the A^B class 4-6-2 Pacific locomotive. Initially, the locomotives were separated into two classes, designated W^AB for mainline work and W^S for suburban work.

The first locomotives, W^S 686 and W^AB 687, were built from the boilers, frames and engine units initially destined for A^B 666 and A^B 667. These entered service in 1917, W^S 686 in Wellington and W^AB 687 at Taumarunui in the central North Island. Fourteen W^S class locomotives were built between 1917 and 1925: one at Addington workshops (686), five at A & G Price Ltd, Thames (799-803) and eight at Hillside workshops, Dunedin (764-771). All the W^S class were converted to W^AB in 1932-4. Sixteen W^AB class were built between 1918 and 1926: one at Addington (687), 12 at Hillside (786-795) and three at A&G Price (796-798). Between 1947 and 1957 11 W^AB class were converted to A^B class.

The remaining locomotives were kept in service until the last days of steam, operating short-haul main line freight services and fast suburban services, particularly in Auckland. W^AB 794 was sold to the Ohai Railway Board in Southland for running heavy coal trains.

The locomotives were progressively withdrawn in the 1960s.

Preserved locomotives

Only three examples of the class remain, with two in their original form as W^ABs.

W^AB 794 is preserved at Feilding, and has been used on main line excursions and also on the regular Wellington - Auckland Overlander service.

W^AB (former W^S) 800 is owned by the Waikato Branch of New Zealand Railway and Locomotive Society and was stored for many years at the Te Awamutu Railway Museum. Following negotiation of a lease agreement, the engine has been moved to the Glenbrook Vintage Railway for eventual restoration to working order.

A^B (former W^AB) 795 is preserved at Kingston, for use on the "Kingston Flyer".

Class register

Key:	In service	Out of service	Auckland Transport service	Preserved	Overhaul	Scrapped

Number	Builder	Introduced[1]	Withdrawn[1]	Notes
686	NZR Addington	01917-04 April 1917	01966-01 January 1966
687	NZR Addington	01917-04 April 1917	01966-01 January 1966
763	NZR Hillside	01923-05 May 1923	01963-04 April 1963
772	NZR Hillside	01924-07 July 1924	01962-09 September 1962
786	NZR Hillside	01926-07 July 1926	01947-09 September 1947	Converted to AB class; withdrawn October 1968
787	NZR Hillside	01926-08 August 1926	01947-10 October 1947	Converted to AB class; withdrawn April 1966
788	NZR Hillside	01926-09 September 1926	01948-01 January 1948	Converted to AB class; withdrawn March 1969
789	NZR Hillside	01926-10 October 1926	01947-08 August 1947	Converted to AB class; withdrawn March 1969
790	NZR Hillside	01926-12 December 1926	01957-09 September 1957	Converted to AB class; withdrawn February 1966
791	NZR Hillside	01926-12 December 1926	01947-11 November 1947	Converted to AB class; withdrawn October 1967
792	NZR Hillside	01927-03 March 1927	01947-06 June 1947	Converted to AB class; withdrawn July 1969
793	NZR Hillside	01927-03 March 1927	01948-02 February 1948	Converted to AB class; withdrawn March 1969
794	NZR Hillside	01927-05 May 1927	01955-08-31 31 August 1955	Sold to Ohai Railway Board; withdrawn 1968. Preserved by Feilding and District Steam Rail Society, operating with mainline certification
795	NZR Hillside	01927-05 May 1927	01947-12 December 1947	Converted as AB class; withdrawn July 1969 Preserved (as AB) by Kingston Flyer
796	A & G Price	01926-09 September 1926	01962-09 September 1962
797	A & G Price	01926-09 September 1926	01963-05 May 1963
798	A & G Price	01926-11 November 1926	01969-03 March 1969
799	A & G Price	01927-11 November 1927	01969-04 April 1969
800	A & G Price	01927-11 November 1927	01969-04 April 1969	Stored at Glenbrook Vintage Railway.
801	A & G Price	01927-11 November 1927	01969-04 April 1969
802	A & G Price	01927-11 November 1927	01969-04 April 1969
803	A & G Price	01927-11 November 1927	01969-04 April 1969

References

1. ^ ^{a b} "Wab Class 4-6-4T Register". http://www.trainweb.org/nzsteam/wab_reg.htm. Retrieved 2009-07-03. 

See also

• Feilding and District Steam Rail Society

External links

• NZ Steam locomotives - W^AB class
• "Last Locomotive unable to get out under its own steam"