NZR DS class


The NZR DS class locomotive is a type of 16 diesel shunting locomotives built by the Vulcan Foundry and supplied by the Drewry Car Co from 1949–1955, for New Zealand Railways.

Introduction

In the late 1940s, NZR was looking for a more powerful type of diesel shunting locomotive to work in the Wellington railway yards. They had trialled a number of TR class shunting locomotives, none at the time were suitable with the most powerful being the five TR class 0-4-0DM shunting locomotives which produced 153 horsepower. These locomotives were too small for the large Wellington yards, where a more powerful locomotive would be needed.
In 1948, the Tasmanian Government Railways took delivery of four Drewry 0-6-0DM shunting locomotives based on the Class 04 shunting locomotives being built for British Railways. These locomotives, Tasmanian Government Railways V class, were powered by a Gardner 8L3 diesel engine producing 204 hp, and weighed 25.6 tonnes. These locomotives were of a standard Drewry design but built by English Electric at their Vulcan Works. A similar diesel locomotive had been built for the Ohai Railway Board in Southland, makers NO 2248/D68 of 1947.

Operation

The first batch of four Drewry 0-6-0DM DS class locomotives arrived in Wellington in 1949 for evaluation. They were allocated the numbers DS 205 - 208, with DS 205 and DS 206 entering service in August of that year, while DS 207 and DS 208 entered service in September 1949. All four locomotives were put to work in the Wellington railway yards immediately after entering into service.
Despite some teething troubles, the initial four locomotives were sufficiently capable of performing the work required. The Railways Department was pleased with the results, and in 1953 ordered seven more locomotives, of Drewry type A-1. At 26½ tons, the new arrivals were slightly heavier than the original four units, which weighed 25.5 tons. The locomotives were fitted with Westinghouse air-brakes, which were more powerful than the original locomotive brakes.
The new locomotives were given numbers DS 209 - 215 and were purchased for work in the South Island. However, two stayed in the North Island temporarily, while the other five were sent to Lyttelton. Here, the new DS class diesel locomotives replaced the F class 0-6-0ST steam tank locomotives used to shunt the wharves.
In 1954, NZR purchased another five A-1 type locomotives, numbers DS 200 - 204, for wharf shunting in the South Island. These locomotives were the last of the DS class to enter service in 1955, with the last being DS 204 in June 1955. The next class of shunting locomotives was classed DSA based on the Drewery "A-2" type. Another three similar locomotives were built for industrial users to a similar pattern.
All of the DS class locomotives and variants were powered by a Gardner 8L3 diesel engine producing 204 hp at 1200 rpm, coupled to a Wilson five-speed epicyclic gearbox with fluid transmission in turn connected to a final reduction and reverse unit. Power was transmitted to the wheels via a jackshaft, to which the wheels were connected by coupling rods. This jackshaft was located under the cab.
The locomotives had a tractive effort of 14,300 lb in low gear, which enabled it to move loads of up to 1000 tons in low gear at walking speed. In a higher gear, the locomotives could haul a lighter load at speeds of up to 30 mph, a respectable figure for a locomotive that had relatively small driving wheels.

Withdrawal and preservation

The withdrawal of the class began in the early 1980s. Several entered into industrial service, while three - DS 202, DS 203, and DS 207 were purchased for preservation by Steam Incorporated, Ocean Beach Railway, and the Glenbrook Vintage Railway. Since then, another four have entered preservation since, DS 213 and DS 215, with the Midland Rail Heritage Trust, DS 201 at the Ohai Railway Board Heritage Trust's site in Wairio, while DS 214 has now been turned into a Steampunk display in Oamaru.
Harry Andrews purchased the locomotive as a source of parts to restore mechanically similar Drewry DSA 234 which had worked for Alliance at their Pukeuri works in Otago. The locomotive was stripped of any similar parts to restore the DSA, and was later painted black before being placed on display at the Carriages Cafe in Glenavy. The DS replaced a four-wheeled Drewry, works 2153, now owned by the Canterbury Steam Preservation Society.
In 2009 the cafe closed, and the DS moved to Brian de Geest's yard in Oamaru. It was then turned into a steampunk sculpture and placed on display in Oamaru's main street in October 2010 during the annual Steampunk Festival. The locomotive is still painted in Glenavy black.