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Productivity Guide: Excavators 45 to 50 metric tons

June 12, 2007 |

The usefulness – and profitability – of an excavator directly corresponds to a correct sizing of the machine to the jobs it is expected to perform. Underestimating this particular bit of alchemy can be disastrous for a contractor: Spec a machine too small, and you get to watch it underperform and – worse – tear itself apart in the process. Get a machine that’s too big, and it sits idle because you can’t get it into the places you need to work or because it’s out-produced its support equipment.

The bottom line for a successful equipment strategy is utilization. There are lots of high-falutin’ ways of charting equipment use, but they can all be summed up easily: If a machine is in action on your jobsite, odds are it’s making you money. If another machine is sitting idle in your yard, shop or on a job, it’s costing you money (unless it’s old and you paid it off years ago – but that’s another story altogether).

It’s these basic equipment use principles that make excavators in the 45- to 50-metric-ton class so desirable to contractors. These machines are slightly larger than the most popular class of excavators currently used in North America. So, in many ways, they’re not much different from the machines you’re probably using on your jobs – they’re a bit bigger, more expensive and can dig and lift more, but it’s not like you’re moving into a mining-class machine. So what’re the advantages of moving up in size from machines in the 30- to 40-ton class?

Productivity, as it turns out. “If a contractor’s not using these machines now, he’s certainly thinking about or dreaming of the day when he will,” says Carl Heggen, product manager, hydraulic excavators, Komatsu America. “Generally, when a contractor upgrades from 20- to 40-ton excavators, he’s looking for the capability of loading slightly bigger trucks, bidding on larger mass-excavation jobs or larger size pipeline work. He can tackle these new applications because excavators in the 45- to 50-ton class have the ability to move more material per hour, lift larger pipe and structures, and power through more severe digging conditions. And hopefully, this additional performance will provide an edge on his competition not available if he were bidding work with smaller excavators.”

Getting through current projects quicker and at a higher production level is also an undeniable competitive advantage. “The idea is that a larger machine, through basic economies of scale, lowers your operating costs per yard and therefore makes you more competitive on the jobs you’re already bidding,” Heggen says.

A 45- to 50-ton excavator has additional weight and higher engine horsepower and more powerful hydraulics to enhance its digging forces, Heggen notes. This means higher production when you encounter tougher digging conditions. A larger machine will allow your operators to break through tough areas more quickly with less stress on the machine than if you struggled along with a machine one or two size classes smaller.

“You’ve got to remember, though, that the acquisition cost is higher than a machine in the 20-ton size class,” Heggen adds. “So a hard, cold look at your business – where it is now and where you predict it’s going – is absolutely essential when you’re considering adding a 45- or 50-ton excavator to your fleet. They can do a lot to enhance your profitability, provided high utilization can be maintained.”

Beware of physics
One reason excavators in this class are so productive in such a wide array of applications is they have the size and power to handle a range of different boom arm and stick configurations. “These machines are great all-around performers,” notes Dave Hardwick, product manager, JCB. “They are powerful digging machines, but can also be spec’d with long dippers, making them ideal for long-reach or below-grade digging applications, or high-reach demolition work with hammers. Other machines can use grapples to place rocks in shoreline or harbor protection work.”