Nine times out of 10, the arm/boom never changes on an excavator," says Michael Boyle, product consultant - excavators, John Deere. Yet, there are situations where added reach is needed, and switching to a larger size class is not an option.
Dredging operations on water are a prime example. Lake Services, Inc., Stafford, VA, is a modest-sized mechanical dredging contractor working off of small sectional barges placed in ponds, lakes, channels and other waterways. Given its typical jobsite, moving to a larger machine is generally out of the question.
"With working on the water, you're faced with a physical constraint," says Martin Firth, owner of Lake Services. As the excavator goes up in size class, a larger barge is needed to carry it. But as barge size increases, any gain in excavator reach is negated. "You really lose a lot of capacity because much of the functional area the machine should work in is actually lost to the deck of the barge.
"The solution is to find an excavator that weighs as much as other machines, but can reach further," he continues. "Therein lies the reason for going to the long reach. It fills the constraint for working on a barge that can't be matched by a conventional, more compact machine."
Advantages of extensions
"Long fronts or super-long fronts can add value for many jobs, including grading over extended surfaces, slope/canal maintenance, barge loading/unloading or light dredging," says Tony den Hoed, marketing communications and product launch specialist - excavators, Volvo Construction Equipment. They are also effective for demolition work at heights, trenching to extended depths, scrap and material-handling operations, etc.
They may also prove more efficient at certain tasks compared to traditional equipment. Again, dredging serves as an example.
"Historically, those applications were handled by a dragline, which was effective, but very inefficient," says Chris Neville, marketing general manager, Doosan Infracore America. "Many customers have said that switching from a dragline to a super-long-reach excavator has reduced the time to clean a retention pond from a week to a day. Moreover, fuel consumption and maintenance are substantially less than a dragline."
Cal Hoffman, co-owner of Kemp & Hoffman, Inc., Denver, CO, began its switch from a dragline to an excavator with a long-reach boom attachment back in 1994. It now owns two Paul Wever Construction Equipment Extendavator attachments, which are typically mounted on a Caterpillar 330L hydraulic excavator. This configuration is used exclusively on drainage projects.
"We clean a lot of ponds and big irrigation canals where you have to have a lot of reach," he explains. "The dragline was getting hard to move around and was pretty big. Some of our jobs are fairly small time-wise, so it was getting inefficient to mobilize it for these smaller jobs."
The excavator with long-reach attachment is now used for sediment removal in small ponds or canals, where the surface of the bank may be too soft to position a machine closer to the work. It also facilitates easier truck loading. "We load trucks a lot because very few of our jobs allow you to stockpile on site," says Hoffman. "So you have the ability to reach not only into the excavation site, but also to the truck, which may not be able to get quite as close without a lot of road work."
Specialized long-front configurations are also available tailored to the task. "Material-handling applications may benefit from straight/long fronts, where the working envelope is mostly above ground vs. digging below ground level," says den Hoed. "If a grapple or magnet is used, a special material-handling arm can make for more effective operation."
Two-piece booms (mounted to the stick) are another, more unique alternative. "This configuration is most popular on our wheeled excavators, which are often used in close quarters — highway jobs, high traffic areas or in urban situations," says den Hoed. "It allows the machine to lift, dig or grade in confined areas with minimal movement of the base machine."