Stuck Equipment Can Stretch Safety Limits
Rain can turn fields into muddy danger zones. Tractors, trucks and equipment can become mired among the crops and as time grows short so can patience.
Don't let waning patience sap prudence. Ag workers should know that tow chains, cables and ropes can turn into deadly slingshots if they're stretched beyond their limits. Every towing device has a breaking point and any combination of chains, cables, ropes and hooks will break at its weakest link when overstressed.
Extra care needs to be used when selecting towing equipment for pulling out mired equipment. Make sure the equipment is strong enough to take the strain."
There is deadly force in every towing device when it is stretched to its limit. And tremendous energy is released when the tensile strength is exceeded. A hook or other heavy metal fixture at the end of the rope can rocket through the air with enough speed and force to damage equipment and injure or kill bystanders.
A one-inch nylon rope is likely to break at about 25,000 pounds. The average tow rope used for large farm equipment has a hook with a lower breaking strength. The hook usually breaks first since the rope is much stronger than the hook. When it does, the rope, chain or cable will fling the hook with deadly force, easily injuring any human in its path.
Note that tractor cab windows and back walls are no barrier to broken hooks, cables, ropes and chains. These projectiles will easily pass through those obstructions and still have enough energy to cause severe or fatal injury.
Towing devices react differently and unpredictably when they
Break. Chain flings wildly and will wrap viciously around anything in its path. Steel cable tends to whip about wildly. Nylon rope frequently rebounds in a somewhat straight line toward the other end.
Selecting the minimum safe sizes of towing components to use in freeing stuck equipment is difficult and dangerous. The power of the pulling vehicles, the weight of the stuck machine, how much pull is needed to overcome the rolling resistance in mud, and the breaking strength of the towing materials all need to be considered.
You can increase your safety margin by following some basic rules when pulling stuck equipment from the mud.
· Only tow ropes, cables or chains that are in excellent condition should be used.
· Inspect every inch of your towing equipment before using it.
· Ropes or cables with breaks in the fibers or frayed, worn spots should not be used.
· Cables with kinks are also dangerous.
· Never use chains that have been repaired.
· A thimble should always be used on ropes and cables, never just a hook because it causes the rope or cable to bend too much.
· Never use a hook that has been stretched, bent or cracked. Never trust a hook that has been reshaped or repaired.
· Damaged hooks and clevises should be destroyed.
· Attach tow ropes and chains only to the drawbar on the pulling tractor and to an equally strong location on the stuck equipment.
· Take advantage of drawbar leverage by attaching as low as possible to the pulling tractor. This reduces the chance that the tractor will tip over backwards. It is generally much safer to pull with a standard four-wheel drive tractor than with a two-wheel drive tractor or a front-wheel drive assist tractor.
· When possible, pull in a straight line to the mired equipment. Pulling done at an angle to the stuck machinery will increase stress on equipment and towing devices and boost the danger level.
· Apply power slowly and smoothly. Sudden applications of power and jerks strain tow ropes and chains past their limits. Lunging with a nylon rope to use its rebound energy is an extremely dangerous practice.
· When a pulling tractor appears to be loaded to it limit or the wheels slip, get another tractor to add to the effort. Each tractor must have its own towing equipment. Use a side-by-side arrangement when adding another tractor to prevent overstressing the tow rope or chain and the pulling tractors. Coordinate the drivers for maximum pull and safety.
