Wire ropes

Wire ropes are used extensively in the mining industry to help hoist equipment. Mine workers also depend on this rope for their safety. Wire rope undergoes both corrosion and abrasion, which will degrade the mechanical properties of the wire and thus reduce its load-bearing capability and cause it to fail. 

A statistical study of mine-hoist wire ropes showed that 66% of the ropes exhibited greatest loss in strength in the portion of the rope in contact with the shaft environment during its service life (26). The Mine Safety and Health Administration (MSHA) of the US Department of Labor requires that wire ropes in service be visually examined for structural damage, corrosion, and improper lubrication or dressing (27). MSHA also requires performance of careful nondestructive testing (NDT) every 6 months and cites one instance where a contractor reported that four ropes were in acceptable condition for use in an elevator shaft. However, less than 6 weeks later, one of the four 12.7 mm (0.5 in.) diameter ropes broke and another was severely corroded with several broken wires (28). 

Wire ropes within the mining industry are routinely replaced every 18-36 months depending on environmental conditions and use over time. The wire ropes are made of carbon steel however, because of their susceptibility to corrosion and wear, stainless steel and synthetic fiber ropes are becoming more widely used instead of carbon steel ropes (25). 

In the mining industry, roof bolts provide support in underground mines by tying the lower layer to a stronger layer located above the main roof. In the United States, 

According to the Connoisseur Corporation Pty. Ltd. (29), the effects of corrosion in electrical and electronic systems in modern mines are often overlooked however, the harsh environment of the mining industry often causes failure of electrical equipment after a short period of time. 

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Safe using of the various lifting machines like cranes, mine hoists, air rope ways, elevators etc. depends on steel wire ropes durability. Ropes are non repairable components of the machines. That is why the ropes worn or failed must be changed. 

Evaluation data taken from the more than 8 thousand reports of the laboratory and field wire ropes inspections show that the visual methods and life time criteria are non adequate to real durability of the ropes in service [4]. The data show that only a very small percentage of all ropes was replaced in a proper time, when one has used a visual inspection. 

Standard Practice for Electromagnetic Examination of Ferromagnetic Steel Wire Rope, ASTM Standard E 1571-94. 

Wire coating Wire, corded Wire covering Wire, electrical Wire enamel Wire insulation Wire materials Wire-rope machines Wires... 

Centering equipment is used to ensure that the impressed current anode is centrally situated in the borehole. The anode with the centering device can be inserted in the borehole by use of, for example, plastic-insulated wire ropes (see Fig. 9-11). After each of the anodes is inserted, the free space is filled with No. IV coke up to the level of the next anode about 50 kg of coke are necessary per meter of anode bed. The wire rope is fixed to a support above the borehole and provides offloading to the anode cable. The anode cables are laid to a junction box so that the... 

Drawworks 525. Drilling and Production Hoisting Equipment 530. Inspection 540. Hoist Tool Inspection and Maintenance Procedures 542. Wire Rope 544. 

Guy line A wire rope with one end attached to the derrick or mast assembly and the other end attached to a suitable anchor. 

Wire Rope. Wire rope for guy lines or erection purposes shall conform to API Specification 9A Specification for Wire Rope. ... 

Wire Rope. The size and type of wire rope shall be as specified in API Specification 9A and by API RP 9B (see section titled Hoisting System ). 

A mast raised and lowered by wire rope shall have the wire rope sized to have a nominal strength of at least 2- times the maximum load on the line during erection. 

Socketing. Socketing of raising, erecting, or telescoping mast wire ropes shall be performed in accordance with practices outlined by API RP 9B. 

A hoisting system, as shown in Figure 4-8, is composed of the drawworks, traveling block, crown block, extra line storage spool, various clamps, hooks, and wire rope. 

Traveling blocks A heavy duty pulley system that hangs in the derrick and travels up and down with the hoisted tools. It is connected to the crown block with a wire rope that ultimately runs to the hoisting drum. 

Deadline tiedowns The deadline is the nonmoving end of the wire rope from the hoisting down through the crown and traveling blocks. This end is anchored at ground level with a tiedown. 

The sheave diameter shall be the overall diameter D as shown in Figure 4-14. Sheave diameters shall, wherever practicable, be determined in accordance with recommendations given in the section titled Wire Rope,"... 

Wire Rope Wire Rope Wire Rope ... 

Wire Rope Nominal Size Radii Wire Rope Nominal Size Radii Wire Rope Nominal Size Radii... 

Inspection and maintenance (lubrication) of wire rope used in hoisting should be carried out on a regular basis. Wire rope inspection and maintenance... 

Wire used in the manufacture of wire rope is made from (1) acid or basic open-hearth steel, (2) basic oxygen steel, or (3) electric furnace steel. Wire tested before and after fabrication shall meet different tensile and torsional requirements as specified in Tables 4-9 and 4-10. 

Selection and testing of wire prior to rope fabrication will be adequate to ensure the after-fabrication wire rope breaking strength and wire requirements can be met. Prior to fabrication, wire tests should meet the requirements of Table 4-10. 

The minimum torsions for individual bright (uncoated) or drawn-galvanized wire of the grades and sizes shown in Columns 7, 12, and 17 of Tables 4-9 and 4-10 shall be the number of 360° (6.28 rad) twists in an 8-in. (203 mm) length that the wire must withstand before breakage occurs. Torsion tests of individual wires in galvanized wire rope and of individual wires in strand cores and independent wire rope cores are not required. 

When testing finished wire-rope tensile test specimens to their breaking strength, suitable sockets shall be attached by the correct method. The length of test specimen shall not be less than 3 ft (0.91 m) between sockets for wire ropes up to 1-in. (25.4 mm) diameter and not less than 5 ft (1.52 m) between sockets for wire ropes 1 -J-in. (28.6 mm) to 3-in. (77 mm) diameter. On wire ropes larger than 3 in. (77 mm), the clear length of the test specimen shall be at least 20 times the rope diameter. The test shall be valid if failure occurs 2 in. (50.8 mm) from the sockets or holding mechanism. 

Classification Wire Rope, Bright (Uncoated) or Drawn-Galvanized Wire, Fiber Core [12]... 

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