Trestle (mill)
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The Trestle of a Post mill is the arrangement of the Main post, crosstrees and quarterbars that form the substructure of this type of windmill. It may or may not be surrounded by a roundhouse. Post mills without a roundhouse are known as Open Trestle Post Mills.
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A Trestle Mill is a variety of Smock mill, usually without weatherboards, formerly used for drainage in the Norfolk Broads.