首页 > Term: shaft collar
shaft collar
A heavy wooden frame erected at the mouth of a rectangular shaft to provide a solid support for the timber sets. A more permanent structure consists of a concrete wall extending from two to eight sets in depth. On this concrete mass is bolted the bearer timbers that support the top heavy set or collar set. The term also applies to the heavy concrete ring at the mouth of a circular concrete-lined shaft.
- 词性: noun
- 行业/领域: 采矿
- 类别 一般矿业; Mineral mining
- Government Agency: USBM
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创建者
- ed.young
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(Milwaukee, United States)