(1) Wood spar trees must be of sound material of sufficient size and strength to withstand any stresses which may be imposed by any equipment used for that specific logging operation.

(2) The top of the tree must not extend more than:

(a) Sixteen feet above the top guylines on spar trees over fifty feet tall; and

(b) Eight feet above the top guylines on spar trees less than fifty feet tall.

(3) School marms used as spar trees must be topped at the forks. Spar trees, except cedar, must be barked where guylines, straps, bull blocks, and tree plates are placed.

(4) Spar trees must be topped and limbs must be cut off close so that running lines will not foul or saw on protruding knots.

(5) At least four tree plates must be placed under top guylines on spar trees over fifty feet tall. At least three tree plates must be used on spar trees less than fifty feet tall.

(6) Tree plates must be equipped with lugs or other suitable means to hold them in place.

(7) Before raising spar trees, dummy trees must be topped and guyed with three guylines equivalent in breaking strength to the mainline.

(8) When spar trees are raised, stumps used for snubbing must be properly notched. Guylines must be held by a mechanical means. Snubbing by hand is prohibited.

(9) All rub trees must be limbed and topped.

(10) Loose material such as bark, spikes, straps or chains not in use and slabs caused by bumping logs or chafing straps must be removed from the spar trees. Heavy bark must be removed from trees used for a permanent installation.

(11) A person must ride only the passline to thread lines, to lubricate blocks, or to inspect rigging.

(12) When the friction lever and passline drum are on the opposite side of the machine from the operator, an experienced person operates the friction lever while the engineer operates the throttle. While being used, the passline drum must be properly attended by another person to guide the passline onto the passline drum with a tool suitable for the purpose.

(13) Using a gypsy drum to handle employees in the tree is prohibited.

(14) A climber's rope must encircle the tree before the climber leaves the ground, except when the climber is riding the passline.

(15) Spikes, used by the climber as a temporary aid in hanging rigging, must be removed before the tree is used for logging.

(16) Topping trees in windy weather is prohibited.

(17) Topping, rigging-up, or stripping is prohibited when visibility is impaired.

(18) When heel tackle is fastened near the machine, a safety line must be placed in such manner that in case of breakage, lines do not strike the power unit and endanger the operator.

(19) Yarding with more than one unit on any one head spar is prohibited.

(20) The angle between the power unit, the high lead block, and the mainline road must not exceed a square lead on rigged spars. When using portable spars or towers, the location of the machine or position of the operator must ensure that the operator is not endangered by incoming logs.