Two very different kinds of backhoe-loader buyers dominate sales of full-sized machines (dig depths of 14 feet and larger), and their very different expectations may have polarized the hydraulic-system designs in this most popular of true earthmovers. The relatively small group of volume buyers from government agencies and large rental fleets are looking for a bombproof machine and tend to be price sensitive. Owner/operators and small-business buyers, while certainly motivated by value, are willing to pay a little extra for proven production-improving features.
In order to take market share in this relatively high-dollar, high-volume machine category, manufacturers must appeal to both groups. They've done so admirably with technologies that can be added to machines as standard equipment. For example, the most recent new backhoe designs (from Caterpillar, New Holland and JCB) have replaced foot controls for extending sticks and auxiliary hydraulics with switches mounted on control levers. They employ finger and thumb dexterity to improve control and clear the floor for more comfortable footing.
Pilot hydraulic controls represent another kind of challenge to backhoe OEMs. These circuits are plumbed in between control levers and the valves on the backhoe's main operating circuits. When you move a joystick in the cab, it activates a pilot hydraulic circuit, which in turn moves a spool on the main-pressure valve. Pilot hydraulics require less lever effort to manipulate the backhoe.
Main pressures in backhoes have climbed to a point where lever effort can influence productivity. Eight of the 35 backhoe models 14-foot and larger have hydraulic-system pressures of 3,500 psi or higher. All eight are available with pilot hydraulic controls, mostly as an option.
Why not make pilot hydraulics standard equipment? One reason is operator preference. Backhoe-loaders have been controlled by levers linked to main valves since their invention, and lots of operators claim they can feel pressure spikes in the hydraulic system when a bucket hits a hard object, like a natural-gas line. Some say pilot hydraulics insulate the control levers to that feedback from the bucket.
Another reason for keeping pilot hydraulics optional is their cost. Nevertheless, most manufacturers (Cat, Deere, JCB, Komatsu, Terex and Volvo) sell at least some of their machines with standard pilot-operated hydraulic controls.
"The inclusion of pilot controls has had the biggest impact on the industry in the last 24 months," says Bob Tyler, with John Deere. "Operator comfort becomes increasingly more important as businesses try to keep their best operators. With pilot controls, operators are less fatigued at the end of the day, and more productive as a result."
Deere makes pilot hydraulics standard on the 17-foot 710G, a machine that, by virtue of its size, is clearly targeted at buyers who are willing to pay for backhoe productivity. But pilot hydraulics are optional on the 15-foot 410G and 14-foot 310SG. They're not offered on the base-model 310G.
Only JCB and Komatsu make pilot hydraulics standard across their full-sized backhoe offering. The other manufacturers retain some models without the feature. Caterpillar, for instance, doesn't offer pilot controls on the 416E, but makes them standard on the 420E and 430E.
Splitting the product line has become common in recent months. Since the first of this year, Volvo made pilot hydraulics standard equipment on the BL70 but doesn't offer the option on the lower-spec'd BL60. Terex announced that it would begin installing pilot controls as standard equipment on the TX970 and TX870, leaving the feature as an option on the smaller TX860 and TX760.
If this is indeed an indication of OEMs fielding a price leader for one set of buyers and a full-featured machine for another, it's also possible that the buyer dichotomy may shape some backhoes' basic DNA.
There is notable inconsistency in hydraulic-system designs used on today's full-sized backhoes. Long-time backhoe-loader OEMs such as JCB, Case and New Holland use open-centered hydraulic circuits with fixed-displacement gear pumps. Those who began manufacturing backhoes more recently, such as Caterpillar, Komatsu and Terex, use closed-center hydraulics.
John Deere started a shakeup several years ago by adding machines with closed-center hydraulics to a lineup that had always used open-center designs.
For Deere — one of the venerable names in backhoe-loader manufacture — to design larger backhoe-loaders with closed-center systems and retain 14-foot machines (the 310G and SG) with open-center hydraulics, there must have been convincing market research measuring a significant customer base for both.
The newest entrant to the backhoe market, Volvo, is making similar moves. Volvo first brought the BL70 with a closed-center system, but followed with open-center hydraulics in the BL60. The two machines are nearly identical structurally — same dig depth and basic dimensions — but the BL60 has a little less engine and hydraulic horsepower.
It's extremely unlikely that an OEM would redesign a system with a higher-cost pump that has even the slightest perception, right or wrong, of shorter life if there was also a strong operator preference for another type of system.
It's much more likely that a closed-center circuit — technology that drives all full-sized excavators — is a very good choice for production earthmoving. Thanks to Caterpillar bringing it to backhoe-loaders in the 1980s, the challenge to other OEMs competing in the product category has been to either make their open-center systems perform more like closed-center systems, or to build a closed-center system that's cost effective for these smaller machines.
All of the JCB backhoes, New Holland's B115, and Volvo's BL60 use open-center circuits with load-sensing valves that can vary pump flow with oil demand. When flow requirements fall, the valve signals one of these machines' twin hydraulic pumps to shut down, reducing the amount of energy the machine wastes pushing hydraulic oil over relief. The feature is similar to the interaction between a variable-displacement pump and the main valve in a closed-center system.
There should be lots of new machines to evaluate between now and the end of 2007, when under-100-hp engines will have to comply with EPA's Tier 3 emissions limits. Real-world issues such as dealer support and operator acceptance should influence those purchase decisions more than pilot hydraulics or closed-center circuits, but it is encouraging to see that sophisticated technologies are shaping the kind of backhoes available. In the end, the industry gets a choice of more-productive backhoes.
|Average Backhoe Costs|
|Dig Depth (feet)||List Price||Hourly Rate*|
|Monthly ownership cost (based on list price and 4.25 percent interest) plus operating expenses (including fuel at $2.49 per gallon and $40.18 per hour for mechanic's wages) divided by 176 hours.
List price jumps to nearly $135,000 for machines over 17 feet in backhoe dig depth, with an hourly rate of more than $54.
|Source: www.EquipmentWatch.com, 800-669-3282.|
|14 to < 15||$71,964||$29.53|
|15 to < 16||$87,759||$36.23|
|16 to < 17||$94,813||$38.35|
|14-Foot Backhoe Specs (by dig depth)|
|Model||Dipper Stick Lift* (lb.)||Loader Breakout Force (lbf)||Hydraulic Flow (gpm)/Pressure (psi)||Operating Weight (lb.)|
|* Lift capacity at 8-foot height|
|This sample includes machines with 14- to 15-foot standard dig depths, the biggest-selling size range. All are powered by diesels in the 80- to 90-net-hp range, with the exception of Deere's base-model 310G and Cat's 416E with 70 and 74 horses, respectively. Komatsu and JCB also build 14-footers with all-wheel steer and four equal-sized tires.|
|New Holland B95||5,870||15,057||40/3,045||14,440|
|John Deere 315SG||5,785||10,300||28/3,625||14,700|
|Case 580M 2||3,750||9,480||28.5/3,050||13,359|
|Case 580M Turbo 2||3,750||9,480||28.5/3,050||13,359|
|John Deere 310G||4,446||8,100||28/2,750||12,800|
|Case 580 Super M Plus 2||4,680||9,480||28.5/3,050||14,905|
|Case 580 Super M 2||4,680||9,480||28.5/3,050||14,285|
|John Deere 310SG||5,785||10,210||28/3,625||13,500|
|Caterpillar www.cat.com||JCB www.jcb.com|
|John Deere www.deere.com||Komatsu www.komatsuamerica.com|
|New Holland www.newhollandconstruction.com||Terex Construction www.terexca.com|