2-4-2 Steam Locomotives in New Zealand

Class K (Locobase 1108)

See also "The Mud Rogers, the history" at [] and "The K88 Restoration" at [], last accessed 28 February 2014. See also Charles Rous-Marten, "The New Zealand Railways 3 ft 6 in Gauge-Their Progress and Results for 1884-Their Locomotive Practice, and New Departures in that Department", No 24575, English Mechanic and World of Science, No. 1,063 (7 August 1885), pp. 499-500; and Charles Rous-Marten, "New Zealand Railways: Their History, Engines and Work", The Railway Magazine (December 1899), pp. 567+. Works numbers were 2454-2455 in 1877, 2469-2474 in 1878.

This octet of narrow-gauge engines known on the railroad as Hudson Double Enders, the last of which was retired in 1929. The "Hudson" referred to in the name was William S Hudson, whose innovations at the Rogers Works included the very successful modification of Bissel's original leading two-wheel truck; see Locobase 16559 for a detailed description of this widely used feature.

Photos show a long wheelbase for these locomotives, a steam dome over the firebox and the sand dome well forward. She had a very straight line. Even the restored K 88 shows the Hudson truck in all its complexity.

Although first described contemptuously as "Yankee toys," according to OS Nock (RWC II, pl 130),"...the enginemen soon found they were capable of hard work, and they became warmly appreciated." This class gave very satisfactory performance. In one instance, a K pulled 90 grain cars and 10 gravel cars (total train load of 700 tons) from Lyttelton to Christchurch. They were also timed at 55 mph (89 km/h) even though the 40-lb (20 kg/metre) rail supposedly restricted speed to 35 mph (56 km/h). Leitch and Sinclair (Trains, September 1983) quote a British railway journalist as saying they looked like watches with all the moving parts on the outside.

All eight went to work on the North Island upon delivery. Rous-Marten's 1885 report, written when he lived in New Zealand, offered a mixed review. While they operated "admirably" heading light trains on mostly level gradients, the Ks were "not equal to heavy loads on the steeper gradients of 1 in 50 (2%) for many miles, which prevail near Dunedin."

As greater train loads overmatched the Ks, the NZR relocated them to express runs on secondary lines. At that time, K93 and K96 moved to the South Island.

See Locobase 1499 for the later rebuild and one member's restoration to service in the 1980s.

Class K rebuilds (Locobase 1499)

Data from "NZR K class (1877)" in Wikipedia at []), last accessed 21 June 2025. (Thanks to George Ferguson for his 12 July email correcting the builder's ID.) Works numbers were 2455-2455 in 1877 and 2468-2471, 2473-2474 in 1878.

After two decades of service, the NZR rebuilt the Hudson Double Enders (Locobase 1108) to the dimensions shown here. The six North Island Ks substituted a Belpaire-type boiler pressed to 160 psi () in place of the original wagon top. In the process, her steam dome moved forward. South Island's K93 and K96 also received higher-pressure boilers, but fitted with a round-top firebox. (Leitch and Sinclair (Trains, September 1983) note the original Rogers boilers were still sound enough to be used in stationary engines for years to come.)

After the rebuilds, these engines carried on until the late 1920s. K88 (Washington - works #2454) and three other Ks were dumped into the Oreti Estuary to shore up the river bank. In 1974, K88 was exhumed from her not-quite-final resting place and restored with much effort by Bob Anderson, a wool buyer and Secretary of the Plains Railway Museum. She required 10,000 man-hours over 6 years and ran again in November 8, 1981 (formal recommissioning coming a year later).

After its 1903 boiler failed in 1986, the PRM raided the necessary funds for Lyttleton Engineering to manufacture a new boiler and the K88 returned to service in 2002. The 2012 10-year inspection took the K88 out of service only briefly, but the 2022 10-year idled her again.

K94's recovery also saw her going to the PRM, but into storage. Fiordland Vintage Machinery Club recoverd K92 from Lake Te Anau in 1985 to rebuild it for museum service, but couldn't complete her restoration. Colin Smith's 1998 purchase finished the overhaul and the K92 served both the Plains Railway as well as visiting several others.