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Updated: October 1st, 2008 10:38 AM EDT

Safely Stretch Out

Hydraulic Excavators

Cat Excavator
Long-reach sticks and booms require a skilled operator who can finesse the excavator and work within the limits.
Deere Excavator
Extra reach comes with a trade-off in terms of crowd force and lift capacity.
When matching an attachment to a long-front excavator, calculate the total load weight (attachment and material), then check the lift capacity chart to see if it falls within the maximum capacity the excavator can safely lift at maximum reach.

Curt Bennink
By Curt Bennink
Senior Field Editor

Almost every excavator manufacturer offers long boom and stick configurations, ranging from a few feet of added reach to in excess of 60 ft. "Super Long Front excavators stretch the digging reach of regular excavators by as much as double," notes Matthew Hendry, product consultant - hydraulic excavators and ADTs, Deere & Company.

Aftermarket attachments are also available in a range of lengths. For example, Paul Wever Construction Equipment engineers sticks and booms from 8 up to 100 ft. of additional reach. "I am a custom builder, so people come to me with their specific needs and we build the extensions that meet the specific job," says Paul Wever.

Such attachments provide more flexibility than OEM long-reach setups, which tend to be dedicated machines. "Obviously, you cannot start lifting manhole covers with a machine that has 60 ft. of reach. So it is hard for some end users to justify having that single tool if they don’t have work for it all of the time," says Wever. "With our attachment, they can add it to the excavator, do their job, then take it off and go back to normal trench digging." The switch takes about three to four hours with a typical 40,000- to 70,000-lb. excavator.

Whether you choose a dedicated machine or aftermarket attachment, there are trade-offs associated with the additional reach. "Lift capacity will be reduced and dynamic instability increased, resulting in the perception of tippiness," says Lew Miller, director of engineering, LBX Co., supplier of Link-Belt excavators.

In addition, long sticks and booms are more easily damaged if not used properly. "Longer booms and sticks are more susceptible to twisting forces than standard-length attachments," says Bret Jacobson, product manager, earthmoving excavators, Liebherr Construction Equipment Co. "Side loads induced through the bucket into the stick and boom will fatigue these structures over time... In some cases, for very long attachments, the stick cylinders and bucket cylinders are downsized to keep forces on the attachment within a range that the boom and stick can safely withstand."

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