ホーム > Term: four-piece set
four-piece set
Squared timber frame used in underground driving to give all around support to weak ground. A cap is supported by two posts on a sill-piece or sill.
- スピーチの一部 noun
- 産業/ドメイン 炭鉱
- カテゴリ 炭鉱全般; Mineral mining
- Government Agency: USBM
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作成者
- ed.young
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(V.I.P) 21084 ポイント - 100% positive feedback
(Milwaukee, United States)
