| 摘要 |
The cost of building a five thousand pound boat lift is substantially cut in half by using three pilings instead of four. The three pilings include a pair of outboard pilings and a single inboard piling. A boat-supporting cradle includes a leading frame member having an outboard end positioned near a leading piling of the pair of outboard pilings and an inboard end positioned near the single inboard piling. A trailing frame member has an outboard end positioned near a trailing piling of the pair of outboard pilings and an inboard end positioned near the single piling. A longitudinally disposed brace interconnects the leading and trailing frame members near their respective outboard ends and a longitudinally disposed plate interconnects the frame members near their respective inboard ends. An equalizer assembly is pivotally mounted to the plate and opposite ends of the equalizer assembly are connected by separate cables to a winch that surmounts the single piling. Another winch surmounts the pair of outboard pilings and supports separate cables that engage pulleys mounted to the respective free ends of the leading and trailing frame members. The winches lift a five thousand pound cradle-supported boat from the water and the equalizer assembly prevents the cradle from rotating about its transverse axis even though it is supported by only three pilings.
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