Encourage the use of "scoring" to penetrate material - in other words, break in one spot, move the tool over, break in another spot and so on. "Sometimes, the rock or concrete will not break the first time," says Sherwin, "so keep repositioning every 15 to 30 seconds until it breaks."
Operators should also be instructed to keep blank firing to a minimum. Blank firing occurs when the breaker is operated with the tool suspended in the air, causing the piston to fire inside the housing. This can be hard on tie rods.
"Blank or dry firing is somewhat inevitable," Sherwin states. "But [it] should be kept to an absolute minimum, as this can potentially cause major internal damage, and at the very least tie rod breakage."
Raking or prying with the tool bit to maneuver material is another common operating mistake. "Operators should avoid excessive prying as it can cause tool point breakage and damage to the hammer," Smith cautions.
"Excessive side loading, or prying, at the same time as firing the hammer will result in tool breakage," Sherwin agrees. "Using the tool to move the broken material around too aggressively will cause damage on the surface of the tool, resulting - in extreme circumstances - in failure of the tool at the point of damage."
The cost of replacing a broken tool can range anywhere from around $400 for a backhoe-loader up to $5,000+ for a large excavator. But the cost to replace other components is significantly higher. "There, you start running into more dollars," says Steck. "You lessen the life you get out of that breaker. You're faced with having to rebuild the breaker sooner than anticipated, and the bill to rebuild gets steeper.
"It's like any piece of equipment," he adds. "Treat it well and you're going to have a better payback."
Minimizing damage by design
No matter how diligent you are in training, or policing, your operators, breaker misuse will periodically occur.
"You can sit there and say don't pry or don't blank fire, but the real world is guys are going to go out there and do it," says Steck. "So it's up to the manufacturers to lessen the damage when that happens."
To start with, breaker manufacturers are simplifying the daily service operators are required to perform. For example, most breaker attachments require greasing of the lower tool holder bushings and tool every two to three hours to prevent metal on metal contact that can cause premature tool bushing wear. Auto lube systems are available to help eliminate manual greasing requirements.
"Auto lube systems - either onboard or excavator mounted - are a worthwhile addition to any hammer package," says Sherwin. "When larger hammers and excavators are being used, the working tool and bushing life are improved significantly by installing auto lubrication."
Allied's latest breaker design takes this a step further by incorporating lubrication into the attachment. "The Allied in-Series Sandvik (Rammer) hammers are sealed to keep lubrication in the hammer and contamination out," says Smith. "This means the operator never has to lubricate (grease) the hammer. This design innovation makes the hammer 'daily maintenance-free'."
Other features in today's breaker designs are intended to minimize the wear and tear encountered during operation. For example, vibration dampening helps to protect both the breaker and the carrier.
"The development of highly effective vibration reduction systems in hammers today does limit the amount of stress that is put on the boom and the excavator in general," says Sherwin.
Arrowhead Rockdrill 'S' series breakers use oversized polyurethane isolators to support the power cell at the top and bottom, eliminating metal-to-metal contact. The compression system also improves vibration dampening, "virtually eliminating any transmission of vibration or recoil up through the boom," Sherwin explains. An added benefit is tie-rod protection. "TRP (tie-rod protection) technology gives increased protection of the power cell against the effects of side loading and excessive blank firing."
Stanley Hydraulic Tools offers features that minimize the negative effects of both blank firing and prying. "We allow the tool bit to drop out of the way so that it's not always in the line of fire if the operator continues to blank fire," Thompson points out. "The tie-rod design has been improved and the lower bodies have been changed to make parts stronger so the lower body can withstand some of the blank firing."