Chain and Cable SafetyDec 4th, 2013 | By Editorial Staff | Category: From our latest issue
By Edward D. Johnson
Editor’s Note: The following article is a more in-depth version of the December issue Tow Times Learning Center topic: Chain and Cable Safety.
Chains and cables (wire rope, synthetic rope) are vital tools in the towing industry, but proper care and maintenance are frequently ignored by tow operators. Both chains and cables should receive a quick inspection before each use and thorough inspections should be scheduled every week or month depending on the severity or frequency of use. Any rope (synthetic or wire) should be certified in writing as to its breaking strength and safe workload and it should be purchased with factory-installed attachments to ensure high quality.
Cables bear great stress during winching and can break and fly through the air to cause severe injury or death. When a cable breaks, it becomes a flying object that can cause hooks or snatch blocks to fly in unpredictable paths. When using wire rope, if a heavy blanket (such as those used by moving companies) is folded over the center area of the rope during winching, there is much less risk of injury if the rope breaks. Blankets made for this purpose are available on the internet. They serve to absorb much of the energy that is released if a wire rope breaks during winching. No person not engaged in the actual winch-out should be allowed anywhere near the tow truck, the vehicle to be recovered, or the rope or chains being used.
Synthetic rope has only recently been marketed to the towing industry and it has advantages and disadvantages when compared to wire rope. Maintenance instructions should come with the rope or be available from the manufacturer when it is purchased. Some winch manufacturers are not convinced that synthetic rope is as good as wire rope for recovery and you should check with the manufacturer of your winch before changing from wire rope to synthetic. Standards for when a synthetic rope should be replaced are not as clear as those for wire rope. Synthetics are less likely to cause serious injury if they break during winching because they quickly lose tension and fall to the ground and they are much lighter. Their safe workload limit is higher than wire rope of the same size and are less likely to cut your hands during use, but they cost about twice as much as wire rope. They are less likely to be damaged during “bird nesting” (when a rope climbs over itself during winching). Synthetics are susceptible to damage from light and can be damaged if exposed to certain chemicals. Care must be used to ensure that synthetic rope does not rub against anything during use. When switching to synthetic rope, you should thoroughly wire brush sheaves to make sure no rough areas or burrs are left that can cut or shave the rope. Synthetic rope is more susceptible to damage from grit than wire rope and greater care must be taken to keep it clean. Use soap and water to wash synthetic rope anytime it has grit or mud in or on it. Do not use chemicals for cleaning.
Chains and wire or synthetic rope should be inspected before each use and thorough inspections should be scheduled every week or month depending on the severity or frequency of use. Any rope (synthetic or wire) should be certified in writing as to its breaking strength and safe workload and it should be purchased with factory installed attachments. Any part not rated or for which instruction and maintenance documents are not available should be deleted from your equipment inventory.
Chains or hooks should be rated by their manufacturer. Chains have traditionally come with specification marks on them but not on hooks, but a welcome trend toward stamping or molding specifications is coming to our industry. Hooks and chains should be kept clean of rust and dirt so they can be easily inspected before and after use for cracks. Any hook that has been stretched from its original shape should be replaced immediately. Chain manufacturers commonly make charts available to assist in determining when their chains have sufficient wear to warrant replacement. If you do not have or cannot get a chart for your chain, the best rule is to replace it if you see any twisted, worn, stretched or out of shape links.