Rope Design Factor

These are the listed breaking strengths of each rope type and size.

Rope design factor. In this reference document an excerpt from the wire rope users handbook you will the factors affecting the longevity of your ropes life. And is working under an operating stress of 20 000 lbs it has a rope strength design factor of 5. An excerpt from the wire rope users handbook. It is recommended not to exceed 1 3 3 1 design factor of the rope s strength to maintain a useful service life.

The size of the drum and sheaves the smaller the d d ratio the size of sheave drum compared to the rope diameter the greater the pressure exerted on the surface of the rope. The for purpose remember the effect of sling angles on load capacities and finally properly store slings when they are finished with to avoid damage. The rope strength design factor is the ratio of the rated strength of the rope to its operating stress. You can express the safety factor as a number e g 10 or a ratio e g 10 1.

Also the definition of design factor is available. Wire rope design factor. If a particular rope has a rated strength of 100 000 lbs. Api spec 7k drilling and well servicing equipment upstream segment fifth edition june 2010 august 2010.

The ratio between documented minimum breaking strength and the working load limit as applied to wire rope and slings. Additionally information regarding the cleaning and lubrication of your ropes is included. This design factor is a factor which is divided into the nominal strength of a sling to arrive at the wll or rated capacity. Design load for the wire rope 15 55 825 kn 825 000 n 3.

This factor is necessary to allow for wear abrasion damage and variations in load which are not always readily apparent to the sling user but does not cover for insufficient edge protection or protection against cutting. If the safety factor is less than 1 it means that the force exceeds the strength and the component will fail. And is working under an operating stress of 20 000 lbs it has a rope strength design factor of 5. If a particular rope has a rated strength of 100 000 lbs.

Rope strength design factors. If our rope is rated at 30 kn and it is holding a 2 kn load we can use this formula to determine that the rope has a 15 1 safety factor. Slings and grommets are all fabricated from steel or synthetic wire ropes. Since the design load is calculated by taking a factor of safety 2 to 2 5 times the factor of safety given in table 20 11 therefore let us take the factor of safety as 15.

Crane design factors 1. The rope strength design factor is the ratio of the rated strength of the rope to its operating stress. It is far from easy to find the correct safety factor for slings and grommets.