The choice of rope for the equipment of a winch largely determines the safety of the handling facility. Therefore it’s essential to consider it as the starting point for any sizing of a winch. This choice is a science in its own right, as industrial players (metallurgists, chemists, drawers, cable and rope manufacturers) have developed for decades multiple metallic and synthetic materials, processes and technologies, aimed at improving the physical and mechanical characteristics of ropes such its breaking strength, flexibility, density, abrasion resistance or corrosion resistance.
First, we can guide the choice of a rope by answering the 3 following questions:
- Application: Pulling? Lifting? For what type of machine?
- Utilisation: Timely? Intensive? Stable? Varied? Whit impact? Without impact?
- Environment: Inside? Outside? Moist atmosphere? Dusty atmosphere? Marine atmosphere ?
Based on the answers, the 5 following technical characteristics will need to be defined:
- Material: steel, polyethylene or polyamide
- Protection: light, greased or galvanised
- Constitution: number of strands and number of wire
- Standing: right, left or torsion-free
- Finishing: standard, compacted or impregnated
Remains to answer an important question, which is often approached at first glance, but it should rather be treated as here, that is to say at the end of the analysis: what should be the Minimum Breaking Load (MBL)? This will depend on the answers given to the 3 questions above but also on the regulatory and normative reference framework on which the customer and the supplier will have agreed in advance. In general, this MBL will be determined by multiplying the Maximum Working Load (SWL) of the winch by a safety coefficient, which can be between 1.5 for simple use to more than 10 for high risk situation.
The choice of a rope remains paramount for the safety, performance and longevity of a cable handling system. It must therefore be entrusted to a professional who not only knows the existing products on the market but also and especially the applications and uses that are made in the different industrial sectors.