Hoist ropes / factor of safety

(1) Each component of the suspension gear between a shaft conveyance or counterweight and a hoisting or tail rope, and any connections between conveyances, shall have a static factor of safety when new, of not less than 10. Welding of ropes (2) Components of a single suspension unit between a hoisting rope and a shaft conveyance shall not be welded. Rope connection (3) A shaft rope shall be attached to the suspension gear of a shaft conveyance or counterweight by a closed-type device that cannot be inadvertently disconnected. Drum and rope attachment. (4) In a drum hoist installation, the hoisting rope of a shaft conveyance or counterweight shall be attached to the drum of the hoist and there shall be not less than 3 rounds of rope on the drum when the shaft conveyance is at the lowest point in the Test trips after (5) When the attachments for a shaft hoisting rope are first installed or reinstalled after dismantling, the hoist operator shall make two test trips of the conveyance, carrying its normal load, through the working part of the shaft. The attachments shall be examined by a qualified person after the trips and a record of the test trips shall be made in the logbook. 139 (6) Before a shaft rope is installed, a 2.5 meter (9 feet) representative sample of the rope shall be destructively tested at a rope testing laboratory acceptable to the Inspector and the test certificate showing the actual breaking strength, the percent elongation at failure, and the results of torsion tests performed on individual wires shall be sent to the Inspector. Initial testing of rope samples. Six month destructive test. (7) Six months after installation of the hoisting rope and at six month intervals thereafter, a 2.5 meter (9 feet) length shall be cut from the lower end of the rope and destructively tested in accordance with paragraph (6) of this Regulation, and the test results shall be forwarded to the Inspector. Electromagnetic testing of ropes. (8) Electromagnetic testing of the entire rope shall be conducted within six months after installation of same and at six month intervals thereafter until the rope has been in service for two years when the interval for testing shall be reduced to every four months. (9) No rope shall be used as a hoisting rope if it has been spliced, reversed, or previously used in a shaft sinking Rope splicing (10) The minimum nominal diameter of a hoisting rope shall be 16 mm (0.64 ins) where a shaft conveyance is supported by a single rope, and 13 mm (0.5 ins) where more than one rope is used. Minimum rope diameters. (11) The factor of safety of a hoisting rope installed on a drum hoist when the conveyance is carrying its maximum permissible load shall not be less than 8.5 at the point where the rope is attached to the conveyance; 5.0 at the point where the rope leaves the head sheave; and 7.5 at the point where the rope is attached to a skip or counterweight, and the maximum load shall be accurately determined by weighing. for ropes on friction hoists. (12) The factor of safety of a friction hoist rope shall not be less than the greater of 5.5 or the value obtained from the for ropes and drum hoists. 140 formula 8.0 minus 0.00164d, where ‘d’ is the maximum length of rope, in meters, in the shaft compartment below the head sheave or friction hoist drum. for tail ropes. (13) The factor of safety of a tail or balance rope shall not be less than 7.0; and for a guide or rubbing rope it shall not be less than 5.0. Removal of rope from service. (14) No rope shall remain in service when its breaking strength is found to be– (a) less than 90 percent in any part of the rope; (b) 90 percent in any part of a multi-layer, multi- strand balance rope; (c) 85 percent in any part of a single layer, stranded balance rope; or (d) 75 percent in any part of a guide or rubbing rope. deteriorating ropes. (15) A hoist rope shall be removed where the destructive test of a piece of a hoist rope indicates that the extension has reduced to 60 % of the original extension test for that rope, and marked corrosion or a considerable loss in wire torsion has occurred; the number of broken wires in any section of the rope equal to one lay length; exceeds 5 % of the total number of wires in the rope, excluding filler wires from the calculations or the rate of stretch of a friction hoist rope shows a rapid increase in its normal rate of stretch.