Ala. Admin. Code r. 480-3-3-.08

Current through Register Vol. 43, No. 1, October 31, 2024

Section 480-3-3-.08 - Hoisting Ropes (Steel Or Iron)

(1) No rope for hoisting or lowering men shall be used when such hoisting or lowering is done by any means other than human or animal power, unless such rope shall be composed of metal wires with a factor of safety determined as hereinafter set forth; provided, however, that such metal wires may be laid around a hemp center. Such ropes shall be inspected daily.

(2)Safety Factor for Hoisting Ropes - The safety factor of a new rope shall be calculated by dividing the breaking strength of the rope as rated by the manufacturer, by the sum of the maximum load to be hoisted, plus the total weight of the rope in the shaft when fully let out.

(a) Hoisting rope safety factors for various depths of shafts shall continuously conform with the table given below:

Minimum

Minimum factor of

Length of rope factor of safety when

(vertical safety for rope must be or incline) new rope discarded

500 feet or less 8 6.4

500 to 1,000 feet 7 5.8

1,000 to 2,000 feet 6 5.0

2,000 to 3,000 feet 5 4.3

3,000 to more 4 3.6

(3)Shaft or Incline Rollers - The safety factor shall be calculated by dividing the breaking strength of rope (as rated by the manufacturer or in accordance with test of sample by the United States Bureau of Standards), by the maximum pull not including friction or acceleration-- that is, by the sum of the maximum weights to be hoisted including weight of skip or car and cage plus weight of material to be hoisted plus total weight of rope when extended to bottom of hoist way. If the hoist way is inclined, the calculated components of the weights parallel with the incline shall be used.

(a) At angle points in incline shafts, the rope shall be supported on rollers or sheave wheels.

(4)Hoist Rope Maintenance - No rope shall be used for hoisting or lowering men (1) if there are six broken wires in one strand of a rope lay (2) if the wires on the crown are worn to sixty-five (65) per cent of their original diameter; (3) if more than three (3) wires which have been reduced by wear more than thirty (30) percent in cross-section are broken in one strand of rope lay (4) if marked corrosion appears (5) if minimum safety factor falls below that specified in these rules. Where it is not practical to caliper accurately rope strands of wire in the field, then the test for wear and remaining strength shall be determined by measuring across the crown of the wire in accordance with methods approved by the Department.

(a) In all shafts containing acid waters, some acid resisting preservative shall be regularly used upon the rope.

(b) The rope shall be attached to the load by the thimble and clip method or the zinc socketing method.

1.Thimble and Clip Method

a. The rope shall be attached to the load by passing one end around an oval thimble that is attached to the load and bending the end back so that it is parallel to the long or "live" end of the rope and fastening the two parts of the rope together with clips.

b. The U-bolt of each clip shall encircle the short or "dead" end of the rope and the distance between clips shall not be less than the figures given in the table below:

c. The following number of caps shall be used for various diameters of six (6) strand nineteen (19) wire plow steel ropes:

(Follow manufacturer's recommendations for other kinds of wire rope).

Diameter Space of rope (inches) Number of clips between clips (inches)

3/4 5 4-1/2

7/8 5 4-1/4

1 5 6

1-1/8 5 7

1-1/4 6 8

1-3/8 7 9

1-1/2 8 10

1-5/8 8 10

1-3/4 8 11

1-7/8 8 12

2 8 12

d. For all wire ropes less than 3/4 inch in diameter, at least four clips shall be used.

2.Socketing Method

a. For wire ropes over 1 1/4 inches in diameter it is recommended that the zinc socketing method be used. If used, the work shall be done by a person experienced in this kind of work.

b. The rope should be securely seized or bound at the end with soft iron wire before the end is cut square. An additional seizing should be placed on the rope a distance equal to the length of the socket from the end. After the rope is trimmed off, the seizing on the end should be removed, the rope opened down to the second seizing, the hemp center cut out, and the wires broomed out; that is, all the wires should be untwisted but not straightened. Then the wires should be thoroughly cleaned in benzene, naphtha, or gasoline, as far as they are to be inserted in the socket, and dipped in commercial nuriatic acid for thirty (30) to sixty (60) seconds until the acid has cleaned each wire. Next, the end of the rope should be dipped in boiling water, to which a little soda has been added to clean off and neutralize the acid, and inserted in the socket and warmed, if the temperature is below sixty-five (65") degrees F. to prevent cooling the zinc too rapidly. The socket is placed with its axis vertical to and coinciding with the axis of the rope; the bottom is sealed with clay or putty; and molten zinc or spelter, heated to a temperature that will just char wood, is poured into the socket until it is full. The socket preferably should be forged from one piece of soft iron or steel without welds.

c. Babbit metal, lead, or other anti-friction material for socketing wire ropes is prohibited.

d. All hoisting rope in use for hoisting and lowering men and materials in shafts shall be examined once every three (3) months by cutting off from the lower end of such rope a section not less than five (5) feet in length (from above clips or socket) and having such section examined carefully both externally and internally for crystallization, wear, corrosion and breaks.

e. If, upon any inspection, a hoisting rope shall be found to be below the requirements set forth in this rule, the rope or that portion of it which is found to be defective shall be immediately discarded for such purposes.

(5)Hoist Rope Reports - In a book in the mine office the operator shall keep a record of every hoisting rope used for hoisting and lowering men, noting the length and cross-sectional dimensions of the rope, the breaking strength of the rope as given by the manufacturers, the name and address of the maker, the date of purchase, the date when put in use, the designation of the shaft and compartment or slope in which the rope is used, the dates of resocketing, re-clamping, and shortening, the length of rope cut off at each such operation, the dates of reversing ends, the date when discarded, the reason for discarding, and other items which appear to him to be pertinent to safe and efficient use of hoist rope.

(6)Lubrication of Hoist Ropes - Every hoisting rope used in shafts shall be lubricated at least twice monthly with a suitable lubricant. Only lubricants recommended by the rope manufacturer and developed as the result of tests shall be used.

Author: Marcus Davis, Workers' Compensation Examiner.

Ala. Admin. Code r. 480-3-3-.08

Statutory Authority:Code of Ala. 1975, § 25-2-13(2).