Ropes, strength

The clip method of making wire-rope attachments is widely used. Drop-forged clips of either the U-bolt or the double-saddle type are recommended. When properly applied as described herein, the method develops about 80% of the rope strength in the case of six strand ropes. 

All calculations are compared to the reference case with steel ropes. Strength and mass values for synthetic ropes are taken as an average representation of the technology while steel rope data is referenced from those ropes which are currently in use at LKAB. 

Figure 6. Hoist rope—strength (Fr) vs. iinear mass (m r)...

Rochelle salt 48-9, 56, 570 rock(s) 821 analysis 394 crystal — see quartz salt, coloured 602 soap 581 ropes, strength of 61 rosacic acid 644 roselite 716 Rose s metal 659... 

SAE J959-1966, Lifting Crane Wire-Rope Strength Factors, 1966 ( SAE J959-1966 ), IBR approved for 1926.1501 (a). 

Henequen. Agavefourcroydes grows ia Mexico where it was first cultivated by the Mayans ia the Yucatan (Yucatan Sisal). The plant produces for 20—30 years. The lower bottom leaves, which are up to 2 m long and 10—15 cm wide, are cut, machine decorticated, and cleaned. Henequen fibers are white to yellowish red and are inferior to sisal ia strength, cleanliness, texture, and length, the other grading criteria. Henequen is grown for local use ia Cuba (Cuban Sisal) and El Salvador. Twiae, small ropes, coarse mgs, and sacks are made commercially from henequen. 

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. 

There is no way of judging the remaining strength of a rusty rope therefore, rusty sling lines should be replaced. Areas adjacent to end connections should be examined closely for any evidence of corrosion. 

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. 

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. 

These strengths tpply only when t test is conducted with both ends fixed. When in use, the strength of these ropes may be significantly reduced if one end is free to rotate. 

A question may develop as to whether or not the wire rope complies with the oversize tolerance. In such cases, a tension of not less than 10% nor more than 20% of nominal required breaking strength is applied to the rope, and the rope is measured while under this tension. 

The nominal strength of torpedo lines shall be as specified in Tables 4-26 and 4-27. When testing finished ropes to their breaking strength, suitable sockets... 

Nominal Diameter of Rope in. mm Approx. Mass Ib/IOOft kg/tOOm Nominal Strength ... 

Performance of Cured Resin Sockets. Poured resin sockets may be moved when the resin has hardened. After ambient or elevated temperature cure recommended by the manufacturer, resin sockets should develop the nominal strength of the rope and should also withstand, without cracking or breakage, shock loading sufficient to break the rope. Manufacturers of resin socketing material should be required to test to these criteria before resin materials are approved for this end use. 

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