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Backhoe loaders: 4 to <15 foot dig depth

June 12, 2007 |

In many ways, you could say the whole versatility revolution in construction equipment started with the backhoe loader. Before the backhoe first appeared in the late 1950s, construction equipment was, for the most part, designed, built and used for single-purpose applications. The backhoe loader, however, was different: One half dedicated loader, and one half digging machine, it did both jobs equally well, with rubber-tire mobility to boot. And it was easy to trailer longer distances. Small contracting firms – including single-man operations – took to backhoes in droves because of the huge amount of diversity they offered.

Today, backhoes remain popular among North American contractors. In addition to the features that first attracted contractors 50 years ago, modern backhoes offer a host of performance-enhancing features, modern comforts and powerful front-and-rear attachment versatility that have allowed them to stave off a host of newer and smaller machines seeking to steal the jobsite spotlight.

Side-shift and extenda-dig options increase backhoe flexibility
Backhoe loaders in the 14- to <15-foot-dig-depth class are used in a wide variety of construction applications including truck loading, grading, backfilling, material handling, site preparation and cleanup, trenching, craning, demolition, etc.

Most manufacturers today say the rear portion of the backhoe is used slightly more than the front loader. Chris Giorgianni, midrange product sales manager for JCB, thinks this usage split is roughly 60 percent backhoe and 40 percent front loader. "That's why we're targeting both the front and rear cab areas for ergonomic upgrades and productivity-enhancing features," he says. "Some of these enhancements include improved operator comfort, better sightlines to the boom and bucket and our new Precision Control System."

Pilot hydraulic control systems and open- or closed-center piston pumps are also standard backhoe offerings. Pilot controls offer contractors greater flexibility as they can be easily switched from backhoe- to excavator-control patterns, usually with a simple flip of a lever. This reduces the amount of training and adjustment time needed when an operator schooled on one type of pattern climbs into the seat and starts to dig.

Both open- and closed-center hydraulic systems offer productive digging and lifting characteristics. Open-system hydraulics use gear-driven hydraulic pumps to propel oil through the hydraulic system. Closed-center systems use piston-driven hydraulic pumps. "Closed-center piston pumps provide full digging and breakout force at any engine speed," explains Paul Grohsmeyer, marketing manager, Caterpillar. "They also give backhoe operators more stick 'feel,' thanks to the feathered hydraulic profile. They allow more precision for tasks like setting pipe when the machine is idling, letting the operator communicate with the ground crew. "Piston pumps also generate less heat and wear due to their design. This helps increase pump efficiency and life, as well as extend hydraulic oil life."

But other OEMs say there are equally important advantages to open-center hydraulic systems, namely lower cost and better hydraulic "feel." "Open-center hydraulic systems use fixed-displacement hydraulic gear pumps," explains Rusty Schaefer, product manager, Case. "These pumps provide maximum feel while maintaining full hydraulic flows at high pressure. This characteristic gives you increased productivity because the pumps provide an optimal balance of power and precision for delicate operations like working around buried utility lines. Gear pumps are also less sensitive to contamination so they're more durable in the field and they're easier and less costly to rebuild, both of which contribute to their lower overall operating costs for backhoes equipped with them."

"Closed-center piston pump hydraulic systems give more precise control, and they also allow an operator to input multiple functions at the same time, without compromising other hydraulic circuits," notes Paul Kindelspire, district sales manager, Midwest region, Komatsu. "These closed-center systems are even more precise and efficient when they are tied in and managed by an onboard electronics system. These systems offer various work modes to exactly match the hydraulics system to the task being performed. On a Komatsu backhoe, for example, selecting the 'power' mode cuts boom movement flow in half, while optimizing lift circuits. This ensures adequate power for the lift and precise placing of materials."