| 摘要 |
The safety pole consists of a metal tube 4.30 m long and 49 mm in diameter, held vertically and fastened to a tree trunk by two attachments (2) and straps (3) at about 0.30 m and 1.8 m above the ground. The top of the pole has a 16 mm diameter ring welded to it for fastening a safety line. Each of the attachments is in the form of a section of tube that fits over the pole, a spacer and a stirrup of 6 mm steel plate that is fastened to the trunk.
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