New Zealand Railways E 66

For the 1 in 15 (6.667%) Rimutaka incline on the North Island, the NZR needed a powerful locomotive at the beginning of the century that could haul trains without the assistance of another locomotive. Previously, these trains were hauled by two class W^F 2-6-4T locomotives which in turn were needed after the Fell locomotives of class H were not powerful anymore for grown train weights.

What the NZR built in their Petone shops in 1906 was a Mallet tender locomotive with a 2-6-6-0T wheel arrangement. What was special were the eight cylinders in total, with all cylinders mounted on the outside in a Vauclain arrangement. The rear cylinders were at the back of the locomotive like on a Kitson-Meyer, but it could be classified as a Mallet since the rear three driving axles were fixed to the main frame of the locomotive.

Built under the Chief Mechanical Engineer A.L. Beattie, it had been designed by Chief Draftsman G.A. Pearson and was dubbed “Pearson's Dream”. It was numbered 66 and assigned class designation E, after the two class E double Fairlies had been officially withdrawn. It was rated for 80 tons at the steepest part of the incline, what was only 15 tons more than the rating of the class H locomotives.

In 1908, the NZR bought the Wellington and Manawatu Railway and now had a flatter line to bypass the Rimutaka incline. Now, the class H was powerful enough to handle the reduced traffic on this incline. E 66 was now transferred to Wellington and worked as banker. Its eight cylinders led to high maintenance costs and so this unique locomotive was withdrawn in 1917.