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The Museum’s Patent Slip Engine is thought to be the oldest engine in New Zealand. Though the Patent Slip has been mentioned before on the website, several people have requested further information. The Slip itself, opened in 1873 with engine built in 1869, consisted of numerous parts: the slipway with track and cradle; the brick engine house at the head of the track; a boiler house which produced the steam to drive the engines; a reservoir with a 5000 cubic foot capacity which collected surface drainage water from nearby hills to supply the boilers; and a jetty running parallel with the underwater slipway. The engine housed double-coupled 25hp engines attached to a winch composed of seven gear wheels of various sizes. This arrangement worked in slow purchase to multiply the engines 17 times. This was combined with two 70 ton chains—one for hauling up and one for lowering. When not in use the chains were coiled in a well of seawater 10 metres deep in the engine house. The ship cradle ran on many wheels and weighed 250 tons. With regards to a definition of Patent Slip, the Oxford Companion to Ships and the Sea notes “a patent slip is an inclined plane on the shore extending into the water, usually gravelled or made of concrete, and fitted with rails up which a vessel, secured in a cradle, can be hauled.”

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