Kobelco has been producing Mass Excavators for over 16 years. The original intention of the Mass Excavator is to move the maximum cubic yardage, with the fewest possible passes, using very large buckets.  The machine uses a specially designed extremely stout boom and arm.

These attachments are designed for maximum durability, required to withstand the high stress imposed by the huge buckets: up to six cubic yard capacity on the SK480LC ME and up to four cubic yard capacity on the SK330LC ME. These are the largest rated loads, for dirt and truck loading, on the market for these machine classes.

The Mass Excavator, a most useful machine for moving large quantities of materials, has proven to be a powerhouse in yet another application: breaking quarried rocks too large for a crusher.

In April 2001, Kobelco’s South Carolina dealer, A.E. Finley, worked with a local rock quarry to specify a machine capable of working a large hammer to break up rocks that were too big for the crusher.  That is not such an unusual request, unless you are faced with rocks up to 8 feet thick! For that you need a hammer of approximately 6,000 foot-pounds of energy, like the Allied Model 805CS.  The problem is that no 30-ton machine’s standard boom or arm could survive such a hammer’s power. The hammer is almost 12 feet tall and weighs approximately 9,500 pounds.  The 30-ton class machine is desired because, for this application, the machine must be transported between six different sites.  This must be done without overweight permits or trucks because it moves so frequently.

A.E. Finley contacted Kobelco for help accomplishing this task. Kobelco decided that the SK330LC Mass Excavator attachment was up to the job, but there were still a few hurdles to overcome. This hammer is sized for horsepower and flow of a 40-ton class machine.  It was never really intended for a 30-ton machine.  Modifications to produce the required flow were easy on the Kobelco Dynamic Acera.  Selectable double pump flow to the auxiliary attachment is standard equipment on these versatile machines.   Normally, this is only used for shears and is would not be used on a hammer mounted to a standard boom and arm.   The high durability afforded by the thickly constructed mass excavator attachment group permits the use of a hammer that would normally be considered oversize for a 30-ton class machine.

The large quantity of return oil also presented a challenge. However, the Kobelco Dynamic Acera’s superior cooling system, with some minor modifications specific to this task, was more than enough to handle the job.  The system was modified to route a portion of the return oil immediately through the machine’s oil cooler, with the remainder going directly to tank, to reduce back pressure and properly cool the oil.  Large diameter return lines were installed to accommodate the oil flow.

The Mass Excavator attachment is designed to use the standard machine counterweight. No additional counterweight was required.  

Front window guarding was also custom designed and installed by A.E. Finley. This is a must on any large hammer application.

The customer projected it would take up to two years to clear up the backlog of over-size rocks in the six quarry sites. However, once the Kobelco SK330LC ME got on the job, the machine completed the clean up in only six months.  The machine now easily serves the needs of all six quarries.

The SK330LC ME has operated for three years in this very harsh environment with excellent results.  Sometimes the special applications market is worth exploring. 

Let Kobelco help with your special applications. To help find a Kobelco dealer near you, use our dealer locator!