Boom Designs Extend Backhoe Performance

Customers always demand more performance out of their backhoe-loaders, particularly on the back end. “In North America, the backhoe end of the machine is used about 70% of the time the machine is operating, so it’s always been an area of focus for our product teams,” says Kevin Hershberger, BHL marketing, Caterpillar.

Several criteria define backhoe performance. “Consider performance specs such as digging depth, forward reach and lift height for truck loading, lift capacity and breakout forces,” says George MacIntyre, global product marketing manager, Case Construction Equipment. “Other important characteristics include machine stability while roading, boom height for transport/working in confined spaces, overall machine dimensions and visibility.”

Other considerations include how much trench you can dig without repositioning the machine, and whether you can see past the boom in the trench or as it’s swinging up and over the side of a truck. “The biggest complaint from the field is the size of the boom, as operators have to look past them into the trench or over them when loading a truck,” says Jim Blower, JCB. The JCB boom is narrow in width and depth to address this issue.

Then there is the issue of strength vs. weight. “The boom has to be able to withstand all of the digging and lifting forces while being as light as possible to get the best performance,” says Blower.

“Strength is a very important attribute when designing the boom,” agrees Jamie Wright, product manager, Terex Construction Americas. “Terex uses an 8mm-thick steel tubular design with its booms, which adds considerable strength and durability to the product. Forged steel at each pivot point reduces wear on pins and bushings.”

A box-style boom design, such as found on Volvo backhoe-loaders, can combine both rigidity and light weight. “The boom is basically a box section with a forging on the bottom and the same forging on the top. It is enclosed,” explains Marcello Bargellini, backhoe product specialist, Volvo Construction Equipment.

Keeping hydraulic lines safe is another priority on any good backhoe design. For instance, many manufacturers route hydraulic lines inside the boom so they are protected, and pay special attention to areas where plumbing has to be exposed. “To the extent that is possible, we always try to use tubes (vs. hoses) for longer life,” says Bargellini.

“Neat routing of hydraulic hoses increases visibility and reduces hose damage,” says Wright. “Visibility to both the loader and backhoe is important for overall efficient operation. A well-dimensioned boom and boom placement give the operator an excellent view into the trench at any position.”

Visibility was one of the focal points in development of Case’s N Series backhoes. “Engineering put great emphasis on making sure that any modifications to the boom design to improve performance would not interfere with the operator’s line of sight to the backhoe’s work area,” says MacIntyre. “Case engineering mapped the line-of-site visibility with new boom design concepts to better understand the impact to visibility with any potential changes to the boom design.”