The Davies Guidewheel Locomotives

Gallery opened: 13 Nov 2017 Updated 26 Nov 2017 Lady Barklay added

The Oreti railway was built on the south island of New Zealand in 1864. To cut construction costs the rail were simply baulks of wood, and the locomotives used a guidewheel system introduced by J R Davies of Australia. It was virtually identical to (and probably copied from) the Arnoux guidewheel locomotives, which went into service much earlier in 1846.

The history of the railway is very well covered by this website and I will concentrate here solely on the technology.

Left: The Davies guidewheel locomotive: 1864 This is a Crampton configuration locomotive; it has a single pair of driving wheels at the rear. The locomotive was carried by unflanged wheels on top of the wooden rail. To keep it there, at each end there was a pair of angled V-groove wheels that bore on the inner corners of the rails. All the rolling stock was built in the same way. How much of the weight was carried by the angled wheels is speculative, but it is clear that only a small fraction of the total weight was available to the rear driving wheels for adhesion. This was an inherent drawback of the Crampton configuration, leading to its eventual abandonment worldwide.

Only two locomotives were built, confusingly called No 2 and No 3; possibly this was because an earlier and much smaller engine called the Lady Barklay was used during construction. No 2 was the only one of the pair to go into service. Apparently she could reach 20 mph, but damaged the wooden track when she did so. The real problem, however, was that the adhesion was wholly inadequate and when it was reduced by rain, snow, or mud she could not move even on level track.

Left: The Lady Barklay This was a very small locomotive for contractor's work. The inclined guidewheels are clearly visible.

The Oreti Railway quickly went bankrupt, in 1867, followed soon after by the provincial government itself. The two locomotives were sent to do useful jobs of work at two different sawmills, one surviving until 1917.

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