For visitors to Seddonville today, the main physical traces of the area's mining history are the Chasm Creek and Charming Creek walkways, both of which follow abandoned railway lines. These routes, driven through rugged country in the late 19th century, are reminders of the West Coast's rich rail heritage.
The Ngakawau-Seddonville branch line was built solely for the transport of coal from mines near Seddonville to Westport harbour, from where it was subsequently shipped around New Zealand by sea.
In contrast to many other railway lines built around the same time, it was not expected that the line would open up new country for settlement because the surrounding country was too rugged for farming. Although there were never any dedicated passenger trains, for many years passenger carriages were attached to freight trains that carried both coal and timber. After 1914 freight volumes gradually decreased, but in 1967 there was still enough freight for a daily train to Seddonville.
Until 1943 the railway line between Westport and Seddonville was isolated from the rest of the New Zealand network. All locomotives and other rolling stock had to be shipped in through the port of Westport.
The first steam engines, used when the line to Seddonville was opened in 1893, were C-class saddle-tank locomotives, supported by slightly larger F- and Fa-class locomotives. It was soon clear that greater power was needed, and in 1898 four Wb-class side-tank locomotives were introduced. In 1929 these were supplemented by larger Ww-class locomotives which became the main workhorses on the Seddonville line for almost 40 years. Steam engines were replaced by diesel locomotives in 1968-69.
With the gradual decrease in coal production, it is surprising that the Seddonville line continued to carry trains until the early 1980s. The section from Seddonville to the Mokihinui mine was closed in 1974, and the track from Ngakawau to Seddonville was closed in 1981. After that the small amount of coal produced from the Seddonville area was carried by road.
Ww 571, one of the last working steam locomotives on the Seddonville line, is now preserved at the Silver Stream Railway, near Wellington
A few years before the line to the Mokihinui mine was closed, two obsolete Baldwin Wb locomotives (built in 1898) were dumped in Coal Creek to protect the line from erosion. In later years there was great interest in these vintage locomotives, and they were subsequently salvaged in 1989. They are currently being restored.