NZR Y class
Y 542 at MOTAT in 2020
Type and origin Power type Steam Builder Hunslet Engine Company Serial number 1443-1445 Build date 1923 Total produced 3
Specifications Configuration: ​  • Whyte 0-6-0T Gauge 3 ft 6 in (1,067 mm) Driver dia. 40 in (1.016 m) Wheelbase 9 ft 6 in (2.90 m) Length 22 ft 10.5 in (6.97 m) Loco weight 23 long tons (23.4 tonnes; 25.8 short tons) Fuel type Coal Fuel capacity 0.85 sq ft (0.079 m2) Water cap. 500 imp gal (2,300 L) Firebox: ​  • Grate area 9 sq ft (0.84 m2) Boiler pressure 160 lbf/in2 (1,103 kPa) Heating surface 522 sq ft (48.5 m2) Cylinders Two, outside Cylinder size 13 in × 20 in (330 mm × 508 mm) Valve gear Walschaerts Train brakes Westinghouse compressed air
Performance figures Tractive effort 10,140 lbf (45.10 kN)
Career Operators NZR Numbers 542-544 Locale Auckland area First run October 1923 (PWD), 1938 (NZR) Last run August 1945 (PWD), February 1958 (NZR) Withdrawn 1957–1958 Preserved 1 Disposition Two scrapped, one preserved

The NZR Y class was a class of three 0-6-0T tank steam locomotives. Built by the Hunslet Engine Company for the Public Works Department in 1923, all three were sold to NZR between 1938 and 1945.^[1]

In service

The three Y class locomotives were sold by the PWD to NZR in two batches, N^O 543 being purchased in October 1938 and N^Os 542 and 544 in August 1945. Originally they were allocated to the Way and Works Branch for construction work but later saw some use by the Mechanical Branch as shunting engines for hire to private industries whose own engines were under repair. The three engines were transferred to the Mechanical Branch in 1951 and received the class letter 'Y' in 1952.^[2] During their service life with the NZR, the locomotives retained their original PWD numbers.

In 1949, N^O 544 was loaned to the Whakatane Board Mills for use on their Matahina Tramway while their two ex-NZR F^A class locomotives were overhauled. This was the most notable use of one of these engines while on loan from NZR to private industry. While in NZR service, the Y class locomotives tended to be based out of the Auckland locomotive depot and were used for shunting purposes there.

Withdrawal

As a splinter class with very little useful capabilities on a modern railway, the Y class were relatively quickly withdrawn. Y 544 was noted at Wanganui in 1956 behind the locomotive depot with a worn-out boiler, before being finally written off on 17 August 1957.^[3] Y 543 remained in service as a working locomotive until withdrawn on 1 February 1958, but remained in semi-storage until sold to Pacific Steel at Otahuhu in early 1964 for scrap.

Y 542 was withdrawn in working order on 17 August 1957 but was then sold to Wilsons (NZ) Portland Cement for use on their private railway at Portland, south of Whangarei.

Industrial service

Aside from the locomotives' service to the Public Works Department, Y 542 was sold in 1957 to Wilsons (NZ) Portland Cement for use on their private railway between the cement factory near Portland station on the North Auckland Line and the company's quarries. Painted in the standard Wilsons livery of blue with red trim, 542 became the second Wilsons N^O 3 in place of an earlier ex-NZR locomotive, D 171, which was scrapped in 1957. 542 continued in industrial service until 1985, by which time it was held in store as a reserve for the company's fleet of Bagnall and Drewry diesel shunting locomotives.

Preservation

Y 542 (Hunslet 1444 of 1923) was sold to Wilsons Portland Cement in 1957 and was used on their internal railway network until 1985, by which time it was kept in reserve. The locomotive was purchased by MOTAT in 1985 and was restored to working order as Y 542. It is currently based on the museum's Western Springs Railway in occasional service.^[4]