NZR D class (1874)

NZR D class
D 140, preserved and in operation at the Ferrymead Railway
Power type	Steam
Builder	Dübs and Company (5), Neilson and Company (19), Scott Brothers (11)
Build date	1874–1890
Configuration	2-4-0T
UIC classification	1B nt
Gauge	3 ft 6 in (1,067 mm)
Driver diameter	36 in (914 mm)
Length	21 ft 6 in (6.55 m)
Weight on drivers	11 tons 10 cwt (25,800 lb or 11.7 t)
Locomotive weight	14 tons 14 cwt (32,900 lb or 14.9 t)
Fuel type	Coal
Fuel capacity	0 tons 11 cwt (1,200 lb or 0.5 t)
Water capacity	300 imp gal (1,400 l; 360 US gal)
Boiler pressure	130 psi (0.90 MPa)
Firegrate area	7.3 sq ft (0.68 m2)
Cylinders	Two, outside
Cylinder size	9.5 × 18 in (241 × 457 mm)
Tractive effort	4,693 lbf (20.88 kN)
Career	Public Works Department New Zealand Railways Department
Number in class	35
Number	6, 16, 18, 46-51, 108-9, 130-1, 137-145, 149, 169-171, 195-98, 221-2, 240, 315, 578
First run	May 1874
Last run	March 1927

The NZR D class was a class of tank steam locomotives that operated on New Zealand's national railway network. The first members of the class entered service in 1874, and all had left the service of NZR by the end of 1927, which allowed the D classification to be used again in 1929.

Introduction

The D class's boiler and cylinders were the same as the slightly earlier C class,^[1] but its driving wheels had a larger diameter^[2] and it was aesthetically different from the C. The locomotives were ordered in a number of separate batches:^[3] the first consisted of eight from Neilson and Company in 1874, five from Dübs and Company and four more from Neilson in 1878, another seven from Neilson in 1880, ten from Scott Brothers in 1887, and the final D from Scott Brothers in 1890. The order with Scott Brothers, placed in 1884, was the first large-scale construction project of locomotives in New Zealand.^[4]

Names

Four of the original 1874 locomotives were named:

• D 143: Trout
• D 144: Kingfisher
• D 169: Possum
• D 240: Snapper

Operation

The D class locomotives were used in a variety of locations. When they were first introduced to New Zealand, the railway network was young and fragmented, and each individual section had its own numbering pattern: this meant that transfers of locomotives from one section to another tended to result in the allocation of a new number, which creates a confusing history up to the point where numbers were nationally standardised. The Ds were not particularly powerful locomotives and were employed on light duties, sometimes achieving speeds of 72.4km/h (45mph) on a level grade.^[5] They often saw service on commuter trains between Christchurch and Lyttelton until superior locomotives took their place,^[6] and they were also utilised at other major locations up and down the South Island's east coast.^[7] In the North Island, one locomotive, D 137, was used in 1905 as part of a "railcar" trial service between Lower Hutt and Upper Hutt.^[8] This featured D 137 hauling a passenger carriage that seated 24 first class passengers, 48 second class passengers, and had a guard's compartment, and was inspired by locomotive/carriage combinations the General Manager of NZR witnessed in the eastern United States. However, the combination was overpowered and uneconomic and did not last long in service.^[9]

Withdrawal

The first D to leave NZR's service departed in 1899 for use with the Public Works Department, and three more followed in the next two years, one to the PWD and the other two to private businesses. However, the rest of the class continued to operate for over a decade. Withdrawal began to take place during World War I; the locomotives had long since been superseded by newer and more powerful engines on the national network, but they were ideally sized to operate private sidings and bush tramways, so many were sold rather than scrapped.^[10] Only eight of the class remained in service at the start of 1920, and the last left NZR in May 1927. The PWD and private industries continued to use D class locomotives for decades - a few examples survived into the 1960s. This included the aforementioned D 137, which operated until 1963 on the truncated portion of the Hutt Valley Line that remained as an industrial rail siding for the Gear Meat Preserving and Freezing Company.^[11]

Preservation

Seven members of the D class have been preserved, although only two are in operational condition. The first D to be returned to operational condition was D 16, owned by the Pleasant Point Museum and Railway,^[12] followed by D 140 at the Ferrymead Railway. Of the other five, D 6 is unrestored at the Ocean Beach Railway, D 137 and D 143 are under restoration at the Silver Stream Railway, D 170 is on static display at Helensville railway station, and D 221 is on static display in Centennial Park in Kaitaia and its sister train (number unknown) residing in a paddock in Kaingaroa.^[13]

References

1. ^ Eric Heath and Bob Stott, Classic Steam Locomotives of New Zealand (Wellington: Grantham House, 1993), 22.
2. ^ New Zealand Steam Locomotives, "D class 2-4-0T"
3. ^ New Zealand Steam Locomotives, "D class 2-4-0T register"
4. ^ D. B. Leitch, Railways of New Zealand (Melbourne: Lothian Publishing, 1972), 160.
5. ^ Heath and Stott, Classic Steam Locomotives of New Zealand, 22.
6. ^ Canterbury Railway Society, "D class no. 140"
7. ^ Pleasant Point Railway, "Locomotives"
8. ^ David Jones, Where Railcars Roamed (Wellington: Wellington Tramway Museum, 1999), 4.
9. ^ Leitch, Railways of New Zealand, 192.
10. ^ Heath and Stott, Classic Steam Locomotives of New Zealand, 22.
11. ^ Tony Hurst, Farewell to Steam: Four Decades of Change on New Zealand Railways (Auckland: HarperCollins, 1995), 131.
12. ^ Pleasant Point Railway, "Locomotives".
13. ^ . Weka Pass Railway's pages on the seven preserved D locomotives: D 6's page, with links at the bottom of the page to the other six locomotives