OAR 437-007-0825
Tree Jacking
(1)
Hydraulic tree jacks must have:(a)
An internal operable load check valve, velocity fuse or equivalent device. When using hoses with a jack, the device must be installed between the ram and the first piece of hose out from the jack.(b)
An operable pressure gauge.(2)
If two or more tree jacks are used and operated with one pump, a one-way flow valve must be used to isolate the hydraulic fluid from one jack to another jack should a failure in the system occur.(3)
A qualified person must determine if it is safe to jack a tree.(4)
Hydraulic tree jacks must have enough lift power for the trees to be jacked and felled.(5)
Two workers, one of whom must be qualified in the use of jacks, must be present at the tree when using hydraulic tree jacks.(6)
The jack seat of hydraulic tree jacks must be level.(7)
A metal plate or pad must be placed between the ram and the saw cuts when using a hydraulic tree jack. The metal plate or pad must be of sufficient area and have a surface design to prevent the plate or pad from sinking into the wood or from slipping.(8)
The hydraulic tree jack seat must be on solid wood inside the bark ring.
Source:
Rule 437-007-0825 — Tree Jacking, https://secure.sos.state.or.us/oard/view.action?ruleNumber=437-007-0825
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