Coal Age Magazine - For nearly 100 years, Coal Age has been the magazine that readers can trust for guidance and insight on this important industry.
Issue link: https://coal.epubxp.com/i/130908
underground mining Synthetic Rope vs. Wire Rope What underground coal operators should know BY BILL PUTNAM By embracing new technology, companies are striving not only to serve their seasoned experts, but also to protect their younger workers and improve their chances of attracting new talent. Today, workers under the age of 30 have been raised around technology, are comfortable with its changing pace, and tend to prefer working with innovative techniques and materials that maximize efficiency. The high-tech rope industry has also participated in this movement by driving the transformation of one fundamental tool—the line. Specialty rope manufacturers are now venturing below ground to help miners transition from using steel cable to custom-engineered synthetic rope for some of their most crucial tasks. Mining is one of the highest-stake tasks rope technology can be applied to, so it's been one that the industry's engineers have taken up with vigor. As a result, synthetic mining cables have been developed that enhance occupational safety for the underground miner. Aside from the intrigue of a good challenge, there are a few other reasons why the synthetic rope industry felt the need to apply application-specific technology to the world of longwall mining. Ergonomic Advantages Mining is a physically demanding trade, and with the average age of underground miners on the rise, companies are smart to do everything they can to take care of their most irreplaceable assets—their people. It is from that mentality that a trend toward more ergonomic products and tools has emerged. It would not come as a surprise to anyone in the field that back injuries in particular are the most common—and most costly—musculoskeletal injury in mining, comprising 31% of claims in a 10-year study conducted by the Mine Safety and Health Administration (MSHA). Choosing the right task-specific cable system can have a huge impact on ergonomics, particularly with regard to the weight and flexibility of cables hauled and manipulated by workers. When it comes to weight, synthetic rope offers an undeniable 48 www.coalage.com Cable Breaking Strength and Weight Diameter (inches) 1/2 9/16 5/8 3/4 7/8 1 1-1/8 1-1/4 1-1/2 1-5/8 1-3/4 2 Breaking Stength (lb) Weight (lb per 100 ft) Cat's Eye Wire Rope* Cat's Eye Wire Rope* 37,400 45,000 53,000 75,000 98,000 120,000 148,000 172,000 230,000 285,000 330,000 390,000 26,600 33,600 41,200 58,800 79,600 103,400 130,000 159,800 228,000 264,000 306,000 396,000 6.2 7.5 9.5 13.5 19.5 23.5 32.0 38.0 57.0 65.0 78.0 92.0 46 59 72 104 142 185 234 289 416 488 567 739 *Wire Rope = Extra Improved Plow Steel with IWRC core advantage. Synthetic ropes are eight times lighter than traditional wire rope, meaning that a 100-lb load of wire-based cable could be reduced to 12.5 lb of synthetic rope, without any loss of functionality or breaking strength. In terms of flexibility, the fibers used in synthetic mining-specific ropes are extremely forgiving and lend distinctly better bend-over-sheave cycling capabilities than their steel counterparts. And with zero water absorption, these ropes are able to maintain their flexibility even in freezing conditions. These factors alleviate the conditions that lead to many lower back ailments, and help keep workers safe, healthy and productive. ing and attaching the clevis can be significantly prolonged by the weight of traditional material. The synthetics industry saw this process as an opportunity to create a better system. In instances like these, lightweight synthetic ropes provide a distinct safety advantage over traditional wire. Lightweight synthetics allow miners to work with maximum speed and agility as they complete this dangerous task. The faster the rope is transported and hooked to the shield and retriever, the sooner the worker can exit the danger zone and the extraction process can resume, minimizing exposure to the gob edge and saving critical extraction time. Reduced Time Spent in the Danger Zone Enhanced Visibility Despite increased use of machinery for the most dangerous parts of a mining expedition, the task of moving a 20- to 30-ton hydraulic shield is still one precarious task in which miners must play the principal role, and in doing so expose themselves to a high level of risk. Since this work involves venturing into an unprotected area where an unpredictable gob edge could collapse, the goal is to keep the miner's window of exposure as short as possible. But in confined, dim conditions, the process of find- The lack of light underground impairs visibility levels and poses an increased occupational safety risk among miners. Most people experience vision changes with age, with the most typical changes involving difficulty adapting to the dark and decreased peripheral vision. This sensorial change amplifies the danger of trip hazards and other threats posed by steel lines, which can camouflage themselves against a dark backdrop. Yale Cordage has addressed this problem with its Cat's Eye reflective rope, which is enhanced with luminous reflective strands and has May 2013