NZR WF Class - The Nelson Section WF

The Nelson Section WF

The isolated Nelson Section received four WF class locomotives from the 1920s onwards to replace its stud of smaller locomotives, primarily the D class 2-4-0T and FA 0-6-2T tank locomotives. These locomotives were smaller than the WF class locomotives, and the arrival of the larger engines allowed for the smaller D and FA class locomotives to be withdrawn, and in the case of the D class engines, transfer to other parts of the NZR network or sale to industrial users.

The first of an eventual four locomotives of this class to be brought to the Nelson Section, WF 404, arrived in 1915 and replaced D 144, one of the original locomotives on the Nelson Section. It was followed in turn by WF 62 in 1919 and WF 395 in 1925, with the last, WF 397 arriving from Auckland in July 1937. All four locomotives were fitted with non-superheated, or saturated, boilers.

The four Nelson locomotives were never fitted with superheaters. Instead, they were equipped with smokebox blowdown valves on the right-hand side of the locomotive, the only NZR locomotives to be fitted with this modification. This was intended to increase the steaming capacity of the locomotives, making it easier to eject the ash, cinders and soot that would collect in the smokeboxes of the locomotives. A small port on the left-hand side of the smokebox was opened to assist this process, allowing one of the crew to brush down the smokebox and clean the spark arrestor.

The locomotives were not known to be in the best condition due to decades of deferred maintenance at Nelson. One example of this is WF 62, which had its boiler inspected in 1926. It was found the boiler had only two years of life left, and notice was given that the engine should not be used after 1928. However, the locomotive soldiered on, and was the last engine in steam on the Nelson Section in 1956.

In 1955, Addington Workshops fitter Noel Mather was sent to Nelson due to the failure of all four WF class locomotives. At that time, WF 62 had been withdrawn earlier that year due to a badly cracked smokebox saddle, WF 395 had not run in some years and was now the spare parts source, WF 397 was out of service requiring valve repairs, new piston rings and side-rod brasses, and new trailing bogie flanges as well as unspecified repairs to sundry minor parts. WF 404, previously the only operable steam locomotive at Nelson, had been removed from service with small cracks in the smokebox saddle. It had been steaming poorly, and its valves were out of time, requiring some attention. Eventually 62, 397, and 404 were returned to service.

The first of the Nelson Section WF's to be scrapped was WF 395. There are no photographs showing WF 395 in service after 1951, indicating that it was probably withdrawn sometime during that year, although it lingered at Nelson as a source of spare parts for another five years. In March 1956, the hulk of 395 was stripped of all useful components and the rest was broken up for scrap.

WF's 62 and 404 were used to run the demolition trains, while WF 397 remained at Nelson as the spare engine. However, 397 was only used once on the demolition trains in April 1956, only to be failed when it dropped a fusible plug. The locomotive was not repaired as both 62 and 404 were in reasonable condition, and therefore 397 would only need to be resurrected should one of the other two locomotives fail.

All three remaining WF class locomotives were withdrawn in December 1956 when the dismantling of the railway was completed. At the time there was consideration to dismantling the locomotives and transporting them to Picton. This did not eventuate, and the three locomotives were scrapped in 1957. Any useful parts were then taken on to Picton and used as spares for their two WF class locomotives.

Although equipped with Westinghouse compressor pumps, photographs of the Nelson Section WF's show that the brake hoses had been removed, although WF 397 sported brake hoses for a time in 1956. Most of the Nelson Section's rolling stock was not air-braked, and so the brake hoses were removed. The remainder of the brake piping remained in case there was ever need to re-equip these locomotives to run with air-braked trains.