Backhoe-loaders and excavators are made primarily for moving dirt or powering attachments. But at times they are used in lifting applications, such as laying pipe or installing trench boxes. Using this equipment in such situations often makes more sense than bringing a crane onto a jobsite.
“Machine utilization, time restrictions and machine costs are some of the factors that contractors use for choosing an excavator over a crane,” says Michael Boyle, product consultant with John Deere Construction and Forestry Division. “The excavator can dig the trench, pull the trench box, spread the bedding material, set the pipe and backfill. The crane can only set pipe and lift the trench box.”
These advantages can bring profit and time savings to your company. However, rigging up your excavator or backhoe-loader for lifting applications also means taking on a new set of safety guidelines.
Built for safety
Manufacturers of excavators and backhoe-loaders understand that their equipment may be used for occasional lifting tasks. “We design our backhoes knowing that a portion of the time they will be used for lifting,” says Bob Tyler, product marketing manager for backhoes at John Deere. “On the backhoe, our PowerCurve boom narrows in the center of the boom for better visibility to the rear of the tractor. Our system pressure, cylinder sizes and component geometry make the Deere backhoes very capable in lifting and craning.”
Kobelco excavators also have several features that aid an operator during lifting applications, including Heavy-lift Hydraulics and Independent Travel, which gives the travel system one pump, eliminating multi-functioning loss of pump flow. “In craning, power and control are the most important criteria. Speed is secondary,” says Bret Berghoefer, marketing manager with Kobelco Construction Machinery. “The Independent Travel feature on Kobelco conventional heavy excavators separates the flow of the two pumps. One is dedicated to the travel system. The other provides hydraulic power to the other functions. This permits craning operations to be performed without requiring the operator to ‘feather’ the controls in order to maintain a constant speed.”
During craning applications with backhoe-loaders and excavators, a lift may be performed with or without the bucket mounted on the machine. “By removing the bucket, the operator can maximize the lift capacity and also improve the visibility,” says Rusty Schaefer, marketing manager at Case Construction Equipment. Case hydraulic backhoe-loaders have a coupler that allows for quick and easy hooking and unhooking of a bucket, with a lift point built right in the coupler linkage.
Caterpillar excavators work with a similar system consisting of a pin grabber mechanism that makes it easy for an operator to drop a bucket and pick up another tool. The pin grabber also has a convenient hole onto which you can hook the clevis. “With the bucket dropped, the operator has an unbelievably clear view when he’s lowering down to the laborers,” says Ken Karpuleon, demonstrator instructor, Caterpillar Inc. “Secondly, you’ve just gotten rid of 1,500 lbs. of weight, so now it’s much easier for your machine to pick that pipe.”
Every excavator and backhoe-loader is rated for a certain load capacity at different lengths of the boom and arm. Load capacities will change depending on whether the load is suspended across or along the undercarriage, the distance from the lifting hook to the ground and the length of the reach. Load charts listing how much your machine can lift in different situations should always be available in the cab. They are also included in the equipment’s operator manual.
Berghoefer notes that the ground the machine is sitting on can affect its lift capacity. “Consider the angle of incline carefully when making a lift,” he says. “A machine sitting on an incline will not be able to lift the same load at a given radius as a machine sitting on flat ground.”