3342
THE NEW ZEALAND GAZETTE.
[No. 86

(3) All hoist-rope sheaves or pulley spindles and bearings shall be discarded when, in the opinion of the Inspector of Scaffolding, they show signs of excessive wear.
(4) All rope pulleys shall be grooved to a depth not less than one and a half times the diameter of the rope designed to pass through them.

STEEL-WIRE ROPES.

12. (1) This regulation shall apply to steel-wire ropes forming part of or used in connection with such appliances as are covered by these regulations.
    (2) The breaking load of any rope other than a rope used for guying purposes shall be not less than six times the maximum dead working load thereof.
    (3) No wire rope shall be used on any crane, winch, hoist, or derrick if it shows signs of excessive wear, corrosion, or other defect, or if in any length equal to eight diameters of the rope the total number of visible broken wires exceeds 10 per cent. of the total number of wires in such rope.
    (4) Eye-splices, sockets, and rope anchorages shall be capable of withstanding 95 per cent. of the guaranteed breaking strain of the rope or ropes to which they are attached.
    (5) An eye-splice shall be made around a thimble, and shall have at least three tucks with a whole strand of the rope and two tucks with one-half of the wires cut out of each strand and made over and under against the lay of the rope: Provided that approved clips may be used with the consent of the Inspector.

CHAIN.

13. (1) The safe-working loads for a short-link chain, and single slings and collar slings, and the safe-working loads for shackle iron shall be in accordance with Table A and Table B respectively in the First Schedule to these regulations.
    (2) Every chain, ring, hook, shackle, and swivel used for hoisting or lowering building material shall be annealed once every twelve months if made of iron and in general use.
    (3) A chain which has been worn so that the wear at any part exceeds 1/16 in. on chains up to 1/2 in. diameter, 5/64 in. for 5/8 in. chain, and 1/64 in. for every 1/8 in. increase in diameter up to 1 in., shall not be used until the work-worn parts have been renewed.
    (4) No chain which has a knot tied in it shall be used for lifting any load.
    (5) Where double or multiple slings are used for lifting or lowering, the upper ends of the slings shall be connected by means of a shackle or ring, and shall not be put separately on to a hook.

HOOKS.

14. (1) Every hook used for hoisting or lowering shall be—
    (a) Of such a shape as to reduce as far as possible the risk of the displacement of the sling from the hook:
    (b) Made of selected wrought iron or selected mild steel of suitable tensile strength and ductility (all hooks should be drawn out of the solid, and should be carefully annealed after forging):
    (c) Of a type approved by the Inspector when used for bucket work.
    (2) A hook shall be considered of sufficient strength if the working load in tons does not exceed the number of square inches of sectional area of the back of the curved portion of the hook; the shank of a hook shall not be subjected to a greater working-stress than 2½ tons per inch of section.

EXTERNAL SCAFFOLDING FOR BUILDINGS OTHER THAN TIMBER-FRAMED BUILDINGS.

15. External scaffolding for buildings other than timber-framed buildings shall be constructed and maintained as follows:—
    (1) Standards shall be not more than 9 ft. apart. Up to 35 ft. high they shall be of timber not less than 4 in. by 3 in. Over 35 ft. and up to 70 ft. from the ground the timber shall be not less than 4 in. by 3 in. for the top 35 ft. and not less than 5 in. by 3 in. for the bottom 35 ft.; if over 70 ft. from the base of the scaffold the timber for the two upper lifts shall be as above, and the lower timber shall be not less than 6 in. by 4 in.