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Rock Grinder Proves Faster Than Hammering In Chicago.  Who? What? Why?

Posted by Mike Booth & Chip Kogelmann

May 31, 2022 6:16:42 PM

Scott Russ had seen Rockwheel drum-style cutters at trade shows and online, but he was unconvinced they could do more than the hydraulic hammers typically employed. J Russ and Company is a forward thinking, full-service site civil contractor who has been working in the Chicagoland area since 1979. From their Lockport, IL headquarters they specialize in mass grading, excavation, site utilities and ground stabilization. 

Scott contacted Rockwheel Americas (Bellefonte, PA), to learn more. While reviewing the job demands and available excavators with the Rockwheel team, it was determined that he needed a high power, aggressive Rockwheel for their Caterpillar 352 Next Gen (55t). Because Rockwheel Americas offers rent-purchase-option (RPO), he decided to rent the monster 300hp G60 twin drum Rockwheel to go after the notoriously challenging limestone in the Joliet, IL area which can reach into the 20,000+ psi compressive strength range. The Rockwheel G60 is the only model in its class with gear reduction boasting up to 47,300 ft lb of torque and nearly 40,000 lbs of pick force, so it offered an opportunity to directly assess rock grinding vs. impact hammering. The job, trenching in rock for the installation of sanitary sewer 3-10 feet deep, was already a handful for the 14,000 ft. lb. hammer which was not meeting their production requirements, so why not take a chance on the newer method.

 Rock grinders have conical carbide teeth installed at a 45° angle which attacks the rock differently than a hammer. This angle of attack goes after the tensile and shear strength of the rock which is much lower (~10-15% of compressive strength) than the compressive strength which a hammers attack. This is a result of the microscopic structure of rock: it contains microscopic cracks which are forced open and enlarged by tension and shear but which are forced closed by compression. (https://en.wikibooks.org/wiki/Historical_Geology/Physical_properties_of_rocks)

 tension compression shear  

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With approximately 60 teeth (depending on specific model) rotating continuously at a typical 60-65 rpm with very high torque, there can be 3000-4000 “bites” per minute. So, although an individual “bite” may not seem significant, the cumulative effect is remarkable! This also explains how a crushed stone product results from the grinding action and frequently this stone is reused onsite rather than hauled away as is the case with hammered rock.

 

On the job site, the result exceeded expectations with the Rockwheel G60 generating two major benefits: a significant increase in production compared to the hammer and the ability to reuse the 2-3 inch backfill created by the grinding process. Moreover, as the photos make clear, the precision of cut and absence of overbreak mean no unnecessary excavation was done.   He was very pleased with the G60 and may soon be adding another Rockwheel for a 40-ton excavator as the work of J Russ and Company expands. The RPO was a low risk path to proving the effectiveness of the rock grinding approach. It allowed use of the tool for an extended period on an active job with their own equipment and operators with the option, but not obligation, of converting to a purchase.

 G60 Rockwheel Trenching

Cuttings from Rock Grinding

 

When it comes to the Rockwheel drum cutters, as more units are successfully deployed nationwide, it’s hard to deny their advantages over hammers for many applications, especially rock trenching. From trenching to foundations, concrete removal to general rock excavation and beyond, Rockwheel offers a faster, higher precision, quieter, and more effective solution. Rockwheel Americas has a national rental fleet, complete inventory of units and parts, nationwide service support and the most experienced team in the business.
For more information visit www.RockwheelAmericas.com or contact direct at tel. 814-466-7134 or email
info@alpinecutters.com.

 

 

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Topics: Trenching, rock grinder, rock trenching, drum cutter, rock cutting

When off-the-shelf drums won't cut it, customize!

Posted by Chip Kogelmann

Apr 29, 2021 5:48:00 PM

While the vast majority of the Rockwheel drum cutters are delivered with our standard bomb proof, hard rock drums, sometimes a job has requirements where special solutions are called for.  Our team is well equipped to design and build custom cutting drums and we welcome the challenge!  Close collaboration with the customer along with our nearly 50-years of experience in rock cutting, provides for application specific drum designs. 

Here we're highlighting a few recent projects but first check out Jeremy Foust, among the best in the biz, laying down some tight passes on a set of XHD severe duty rock cutting drums.

Rockwheel Drum Cutter Welding

70" wide drums.  A quarry in Texas which specializes in producing road base material for the oil fields was replacing an obsolete cutter and needed to boost production.  They had a 50+ ton excavator which had the power, weight, and hydraulic capacity to run the uber-powerful G60 Rockwheel drum cutter.  This 300-hp gear driven, rock eating, base pumping, Rockwheel has a gear reduction ratio of 1.2.  This means that every ft-lb of motor torque is magnified by 20% for the highest pick penetration force on the market.  With this power and an assessment of the rock physical properties we were able to increase drum width to 70" (1.8m) without sacrificing cutting performance.  The result was a massive increase in cutting rate (CY/hr).  Take a look...

Special drums for ladder dredge.  Once again, in Texas a unique project.  A cutter head was needed for cutting hard abrasive sandy material to be mounted on a ladder dredge.  A 200-hp G40 Rockwheel hydraulic rock ginder was selected and custom 50" drums with optimal pick lacing (the pattern of the teeth on drum) were designed and built.  The photos below show how this was just the right fit for dredge. Note the wear protection blocks. 

Rockwheel rock grinding attachment

G40 Rockwheel drumcutter

Narrow cutting drum options are available as well.  These are frequently requested for trenching operations.

Rockwheel Americas is the go-to source for hydraulic excavator-mounted rock cutting attachments.   With the largest Rockwheel drumcutter rental fleet in North America and unmatched support we're grinding it out on a daily basis to change the way hard ground is excavated.  Contact us direct or have your local equipment dealer give us a call.  814-466-7134 or visit www.alpinecutters.com  DEALER INQUIRIES ENCOURAGED

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Topics: Rockwheel, drumcutter, rock grinder, rock trenching, Antraquip, rock cutting

Low disturbance and rapid removal of concrete walls

Posted by Chip Kogelmann

May 14, 2018 6:28:55 PM

 

The Challenge:  Along a vital waterway managed by the USACE (United States Army Corps of Engineers) a customer needed to remove several sections of 4-ft thick x 8-ft high concrete walls.  Concrete was unreinforced with a compressive strength of 4000-psi ( 27.5 MPa).  Vibrations needed to be kept to a minimum to ensure no disturbance to adjacent structures.  Access was limited to an earthen bench about 25-ft away on the opposite side of  a cut.  Hydraulic hammers would cause too much disturbance via vibrations and shock waves and were not permitted plus they did not have the capability to provided the desired profiled finished surface.  How best to remove these ?

Concrete monoliths that need to be carefully removed

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The Solution:  In consultation with Rockwheel Americas a model D20 Rockwheel (95hp) rock and concrete drum cutter was selected to be installed on a CAT320EL excavator.  The Rockwheel was in-stock and ready to go thanks to Rockwheel Americas extensive inventory and national rental fleet.  We advised the excavator technician on setting hydraulic flow and pressure for optimal performance.  It is always worth the time on the front-end to get the auxilliary hydraulics dialed in so drum speed (rpm) and torque suit the task while making sure multi-functionality on the excavator is not compromised.   The Rockwheel installation was  "plug and play" thanks to clean hose routing that matches that of the excavator hydraulic lines.  No case drain line required and no long hoses crossing the stick.

Rockwheel rotary concrete drum cutter in action

 

Performance:  The customer was very pleased with the performance and expects to speed up the process as the operator becomes increasingly skilled with the Rockwheel.  The high torque Rockwheel rotary drum cutter was the ideal solution.  Smooth and continuous concrete grinding was rapid and precise.  Moreover, after two 34-yd3 sections of the wall were removed the customer remarked: "teeth wear is virtually zero right now, tips look great after 2 monoliths".  High quality carbide conical teeth are always in-stock and can be overnighted anywhere in the country but we recommend keeping a few sets on the job at all times.  Clean up was easy thanks to a cutting by-product typically 2" or less in size.  Compare this to the blocky remains after hammering which are difficult to haul and dispose.

The base of the cut was smooth and flat, ready for the next phase of the job.  It's cliche but its all about "the right tool for the job".    Excavator mounted rock and concrete grinders are one of the fastest growing attachments on the market.  No longer a tool for mining and underground construction, these are a versatile attachments that should have a place in every serious contractors toolkit.  Add one to your arsenal.   www.alpinecutters.com  Rockwheel is the original rotary cutter...get only the best.

Remaining wall base after grinding by Alpine Rockwheel

 

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Topics: Concrete Grinding, Rockwheel, drumcutter, rock grinder, rock trenching

No Hammering?  No Blasting?  No problem! ... when you have a Rockwheel

Posted by Chip Kogelmann

Oct 24, 2017 4:26:16 PM

Just last week I was in Hamilton, Ontario, Canada on the western shore of Lake Ontario.  Beautiful part of the world.  Much of Hamilton is perched on karst topography which involves geological formations with  subsurface drainage, caverns and passages caused by dissolving rock, especially prevalent in limestone formations like the Niagara Escarpment.  We were at a site where underground infrastructure was being installed for water and sewer services.  This means trenching and you didn't have to go very deep until shelf rock was encountered.  Where it was permitted the contractor was blasting the rock.  Elsewhere hydraulic hammers were in use along with excavator mounted hydraulic rotary drum cutters (i.e. Rockwheels).  In some areas of the site, due to the presence of underground karst features, blasting and hammering was explicitly prohibited.  In these areas the only option was the Alpine Rockwheel drum cutter.  Rockwheels are the lowest vibration method of rock removal.  Precise and rapid grinding of the rock limits the disturbance to the surrounding rock mass.   A Rockwheel model G40 (200hp) was utilized.  Production rates varied depending where we were on the site.  Rockwheel rock grinders excel where there are natural fractures and weakness planes but even in the solid rock the rock cutting attachment got the job done.  The trench was cut to exact specifications with no overbreak which is a problem with hammers.  Cuttings could be reused as backfill saving hauling costs.   Rockwheel Americas a division of Alpine has a large inventory of units for rental and purchase.  Call 1-814-466-7134 or email info@alpinecutters.com to get more information.  You can alwasy find us online at www.alpinecutters.com 

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Topics: Cutter Heads, drumcutter, rock grinder, rock trenching

About this blog

This blog is a resource for research, how-to's, and general news regarding rock grinders, transverse cutter heads, roadheaders, and alternatives to hydraulic hammers. 

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