1. (a) Hydraulic tree jacks purchased after January 1, 1980, shall be equipped with:

   1. (1) An operable load check valve, velocity fuse or equivalent device. When hoses are used with a jack, the device shall be installed between the ram and the first piece of hose out from the jack.
   2. (2) An operable pressure gauge.
2. (b) If two or more tree jacks are used and operated with one pump, a one way flow valve shall be used to isolate the hydraulic fluid from one jack to another jack, should failure occur in the system.
3. (c) Hydraulic tree jacks shall have enough lift power and be of sufficient in number for the trees to be jacked and felled.
4. (d) A metal plate shall be placed between the ram and the saw cuts when using a hydraulic jack. The metal plate or pad shall be of sufficient area and have a surface design to prevent the plate or pad from sinking into the wood or slipping.
5. (e) If the faller is pumping the jack at the base of the tree, wedges shall be used as a follow-up method while using tree jacks. The wedges shall be progressively moved in as the tree is jacked.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.