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Rockwheel D20 trenching in West Virginia sandstone and blue rock...a microcosm on the paradigm shift in rock excavation

Posted by Chip Kogelmann

Apr 13, 2017 6:40:13 AM

With winter finally coming to a close the construction season in the Mid-Atlantic region is picking up steam.  With this seasonal uptick we at Alpine Rockwheel are getting more and more calls as excavation contractors and engineers recognize the benefit of Rockwheels as an alternative to hydraulic hammers in many rock removal applications. Excavator mounted rock grinding attachments (Rockwheels) have reached a tipping point where it has become clear that something has been missing from the toolbox for economical removal of rock.

Here it is in a nutshell:  Ground strength varies along a continuum starting from soft ground that can be excavated with buckets (with or without ripper teeth) to extremely hard rock that requires heavy hammers or drill-and-blast.  Between these two extremes is a wide range of rock strength from approx. 1200 to 15,000-psi where excavator mounted rock cutting attachments are the most effective tool.  They are more efficient because:

  • Continuos grinding:  Less time re-positioning the tool compared to hammers
  • Higher production:  3-5x the producting of hammers in suitable rock (especially in layered rock!)
  • Precision:  eliminate overbreak and dont excavate more than you have to
  • Reusable cuttings:  ground rock can be recyled onsite as backfill or more easily transported


Case in point is a recent rock trenching job in West Virginia.  The contractor had to trench through 3-ft of sandstone underlain by  3 1/2 ft  of blue rock (limestone).  In addition, they were crossing some existing utilites that could not be disturbed.   Knowing the limitations of hydraulic hammers in terms of ability to cut smooth trench walls and flat bottoms he decided to use a D20 Rockwheel hydraulic rotary rock grinding attachment.  Installed on a 20-ton excavator the Rockwheel exceeded expectations in terms of productivity and finished product.  In the photo below you can see the rock layers, smooth exact side walls, and a crossing utility line that was undisturbed.  


Could a hammer have done this job?  Sure, but it would have been much less efficient and cost effective.   Hammers will always have a place in the the excavation of rock but the current paradigm shift is raising awareness that there is a better option for a wide range of rock types.  It's all about the right tool for the job and having a toolbox equipped with a range of options.

Alpine maintains a national rental fleet so you can try this equipment for yourself without a purchase commitment. Excavator dealers and rental houses can utilize our rental fleet to offer their excavators equipped with Rockwheel rock cutting attachments.    From our long history in the mining and underground contruction markets we are excited to bring rock grinding technology to your excavator!  Contact us to let us know how we can help.  Tel.  814-466-7134  email.  chip@alpinecutters.com  www.alpinecutters.com 


Topics: Cutter Heads, Trenching, Excavation, Rockwheel

D20 Rockwheel for rapidly removes outcropping limestone....then grinds some large stumps!

Posted by Chip Kogelmann

Mar 11, 2017 10:40:32 AM




If you live in Pennsylvania, USA chances are there is underlying bedrock which at times is exposed at the surface as outcroppings.  This prevalence of rock (limestone, shale, & sandstone) presents a challenge for any form of earth work be it trenching (sewer and water), preparation of foundations for buildings, grading along roads, and even farming where outcropping rock can damage expensive planting and harvesting machinery.  

The traditional solution to this problem is to use hydraulic hammers.  While these tools can get the job done, drawbacks exist.  Hammers (a.k.a. breakers or hoerams) are very loud and have high vibrations which affects the surrounding rock mass and upsets neighbors. In addition, hammers are not capable of precise removal of the rock.  Overbreak is a common problem resulting in extra time and expense.  Moverover, the large chunks of broken rock cannot be reused without additional crushing otherwise it musted be hauled offsite which is costly.  There is frequently a need to remove only a thin layer of rock, say 6"-12", but with hydraulic hammers twice that can in inadvertantly removed.

There is a far more efficient and economical option.  Alpine Rockwheel rock and concrete grinding attachments are the solution.  These excavator mounted rock and concrete cutting attachments can rapidly remove the rock to a precise cut line (within 1"-2" with a skilled operator, or better when a depth control guide is used).    Moreover, in trenching or footer jobs, rock grinding attachments leave smooth walls, sharp corners and flat bottoms.  Trench profiles with rock cutting attachments are slot shaped compared to the V shape common with hammer.  This means you're not excavating unnecessary material.  Finally, you're left with a crushed stone that can be reused as backfill.

This winter a business owner in Shippensburg, PA wanted to expand his builiding but immediately adjacent to the existing struture was a 6-8 ft thick limestone bedrock outcrop in the way.   The customer decided to use a D20 (95-hp) Rockwheel excavator mounted rock grinder (Rockwheel) on a Volvo EC220.  The Rockwheel is powered by the standard auxilliary hydrualic kit of the excavator and installs like a hammer with a simple two line system.  With a peak torque of over 13,000 ft lb, the Rockwheel was very affective and made quick work of the rock removal.  The excavator operator quickly learned the correct down pressure to maximize rock cutting performance and was impressed by how smooth the D20 cut, espeically compared to using a hammer.  Once the main job was done, they installed a set of wood cutting teeth and removed several large diameter stumps. 

All in all, it was a very successful job!



Topics: Cutter Heads, Excavation

G45 Rockwheel takes 14,000 psi rock to task in New York wastewater treatment plant construction

Posted by Chip Kogelmann

Nov 1, 2016 9:51:49 AM

Two 200-hp G45 Rockwheels installed on CAT349 excavators have helped the contactor complete a challenging rock excavation project in New York state.  Geo technical data indicated rock to be in the 14,000 psi range.  Because they were excavating next to an operating treatment plant, hammers and explosives were too risky because of possible collateral damage.  In addition the rock excavation went right up to newly set caisson walls and concrete support pillars.  The G45 rockwheels were favored because of low disturbance to surrounding structures and becasue of their ability to cut continuously.  In additon to the two G45 Rockwheels a smaller AX20 and D10 were used where even more precision was required.  Excavator mounted rock cutting tools from Alpine Rockwheel are available world wide.  www.alpinecutters.com




Topics: Excavation, Rockwheel

High precision rock removal with D30 Rockwheel

Posted by Chip Kogelmann

Aug 9, 2016 7:10:33 PM

The Rockwheel D30 is getting some great press from down under.  Extremely precise rock grinding with minimum disturbance to the adjacent material.  The same applies to tunneling work and concrete removal on sensitve structures. Alpine stocks the full line of Rockwheels for excavators in every size class.  Rental rock grinders are always available as well so you can try them on your equipment at your jobsite.  The Rockwheel will prove its worth!Australia.jpg

Topics: Roadheaders, Tunneling, Excavation, Rockwheel

Precision rock removal with Alpine Rockwheel

Posted by Chip Kogelmann

May 31, 2016 4:57:16 PM

An interesting project is underway in the State of Indiana in the USA.  The contractor is using an Alpine D30 Rockwheel installed on a CAT336 excavator to precisely remove 4-ft of hard limestone shelf rock in order to place 96-ft long concrete box culverts in a river tributary.  The job required rapid and precise rock removal as well as a smooth, flat finished surface.  The D30 rock grinder was the ideal tool for this job.  Hydraulic hammers were not an option because of the rough irregular surface they create and inability to cut accurately within inches to get the final grade right.  A further benefit was the generation of ground rock which can be reused onsite rather than hauled away.  Alpine Rockwheels are the go-to tool for rapid and precise rock cutting.  See video:  https://youtu.be/a1PdLC_feac 



Topics: Excavation, Rockwheel

How Deep into Rock Will a RockWheel Cut?

Posted by Ryan Leech

Apr 14, 2015 10:30:00 AM

deep_cutterheadWhen you are placing a bid on an excavation project there are an abundance of factors that you are taking into consideration.

There are concerns about the geographical location of the project site and the conditions you will potentially face and what equipment and manpower will be necessary to complete the task to the customer’s highest level of satisfaction.

One piece of equipment that is extremely useful in a variety of excavation applications is a cutterhead.

Like most tools, cutterheads come in a variety of options, including specialized custom cutterheads available for particularly challenging or unique situations.

Cutterheads offer numerous advantages over simpler excavating products such as hydraulic hammers.

The enhanced functionality of a cutterhead will give you more precise control over the quality and structure of your Rockwheel_foundationexcavationexcavation projects.

In addition to better overall performance, cutterheads also have the ability to lower costs and improve the efficiency of your project as well.

How deep will a cutterhead cut?

Today we’re going to look specifically at one aspect of cutterhead performance that is important to excavation projects, namely, how deep will a cutterhead cut?

The short answer is that cutterheads theoretically have the ability to operate at any depth, but they are dependent on the excavator or carrier machine they are attached to for reach and depth.

The power and rate at which a cutterhead operates should be constant, so the biggest restriction to a cutterhead’s ability to cut is how far the carrier machine can physically put the cutterhead into the ground.

This means the machine type will obviously have an impact on how the cutterhead performs. Knowing what excavator or carrier machine you have will affect the scope of your project.

Know beforehand what type of excavator or carrier machine you will be attaching your cutterhead to and you’ll be able to determine how deep your cutterhead will be equipped to cut.

Different machines have different capabilities, and even factors such as the machine’s weight and dimensions will change the way a cutterhead performs.

If you have any specific questions about an attachment or need help installing a cutterhead, feel free to contact one of our team members here at Alpine.

There are a few other factors that will directly impact the depth at which a cutterhead will perform.

These include the specific type of cutterhead you select as well as the surrounding conditions of the project site.

The soil type and the surrounding landscape such as the presence of fault lines, utility lines, and any other obstacles will have a direct correlation to how deep the cutterhead can safely excavate.

Cutterheads have the capability to operate at any depth you need to get the job done, and most scenarios will need to be evaluated on a case by case basis.

Find out everything you need to know about rock grinding with a cutterhead



Topics: Cutter Heads, Trenching, Excavation

Bedrock Excavation with Adjacent Sensitive Structures

Posted by Ryan Leech

Oct 13, 2014 11:27:00 AM


Excavation of bedrock adjacent to aging or historic historic structures on problematic foundations is not a task for the faint of heart. Blasting is definitely a no-go and large impact hammers can cause seismic waves that propagate and cause micro or macro fractures well away from the work zone, potentially weakening the existing foundation leading to cracking or in the worst case, collapse. Moreover, hydraulic hammers are not suited for such “dental work” where precision rock removal is required. Unintended overbreak is also a significant risk. 

This is a case where Alpine rock grinding attachments (aka RockWheels) are often the tool of choice. 


Through a high-torque (up to 41,400 ft lb),  low-speed (60-120 rpm) cutting action rock grinders attack the shear strength of the rock by “raking” at a 45°-50° angle with conical carbide tipped teeth (picks). Cutting drums typically have 50-80 picks depending on width. Picks are arranged in a spiral fashion with successive picks offset laterally.  As the rotating drum cuts, picks overlap the fracture zone created by the ones ahead. 

The result is an excavation mechanism vastly different from hammers (cutting vs. breaking) and much lower vibrations compared hammers. Smooth, continuous cutting keeps disturbance to surrounding rock and structures to a minimum. Rock can be removed rapidly and with a precision simply not possible with hammers. Tight corners can be milled and walls and bottoms can be made smooth.  Another benefit is the usability of the cuttings. Instead of hauling off large rocks and crushing and disposal, the milled rock (typically 1”-3”) can be reused on site as bedding or back fill eliminating costs associated with transport.

Recently an Alpine TC-E (190-hp) was successfully on a Komatsu PC390 in Bellefonte, Pennsylvania just across the street from the historic courthouse built in 1805. Limestone bedrock with a strength of 15,000-20,000 psi was successfully cut without disturbance to adjacent historic brick buildings or the underlying rock. 



Topics: Excavation

Hyundai and Volvo Use July to Introduce New Excavation Products

Posted by Ryan Leech

Jul 31, 2014 7:00:00 AM


Hyundai Construction Equipment Americas, Inc., long recognized as one of the leaders in earth moving and material handling equipment manufacturing has expanded their offerings in the North American market.

The company announced this past week that it will be rolling out a line of attachments to accompany their supply of excavators.

The new series of attachments boasts 15 models and marks the first time Hyundai has offered these products in North America.

To mark their entry in the new market, Hyundai announced a new HDB hydraulic breaker series.

With 15 different models and a variety of features, the breakers offer a significant amount of versatility and can be useful in a wide range of applications.

The attachments have a powerful capacity, operating with a chisel diameter ranging from 1.6 to 7.9 inches. Other specs from the breakers include operating weight ranges from 271 to 21,401lbs and lengths range from 44.4 to 159.8 inches.

The HDB series breakers also come equipped with innovative technology to improve productivity. Some key features include an Anti Blank Firing (ABF) system designed to stop the breaker to continue breaking material after it has been crushed. Another feature that gives operators improved control in the field is a Two Stroke Selector system that comes standard on most of the models.

The Two Stroke Selector System gives operators the ability to decide whether they want long strokes or short strokes depending on the circumstances.

While Hyundai expands their offerings to attachments, Volvo Construction Equipment announced recently a launch of crawler excavators that put an emphasis on fuel efficiency.

The two crawler excavators are the Tier 4 Final EC250E and the EC300E.

These two excavators come outfitted with a full set of technologically advanced features.

These features enhance efficiency and give manual control the flow to hydraulics by implementing an integrated work mode system. By giving operators the ability to vary their approach based on the conditions of the current job they can work more productively.

One of the excavator’s best design features is that they reduce fuel consumption without compromising performance.

Volvo has designed an ECO mode for their excavators. This mode allows operators to set idle controls that will automatically reduce engine speed if the machine is idle for too long and shut down completely if the machine remains inactive for 5 minutes.

Several other features make these excavators fuel efficient options that several companies could find appealing.

These new products come at a time when construction projects are on the rise and demand is growing. Continuing to invest in innovative solutions will help deal with the increasing number of projects in the best way possible.

July was a big month for new excavation product offerings in the North American market. As companies continue to develop creative solutions to problems in the industry, expect more to come.

Find out everything you need to know about rock grinding with a cutterhead


Topics: Excavation

Cat Demonstrates Mini Excavator Versatility with Latest Viral Video

Posted by Ryan Leech

Jun 13, 2014 7:30:00 AM

cat-demonstrates-mini-excavator-versatility-with-latest-viral-videoAs construction companies face the reality of an aging workforce and the difficulty of finding young skilled workers, they also face the task of changing the public perception of the industry.

The German Engineering Foundation, VDMA, is a good example of taking a proactive approach to adjusting perception at the Bauma 2013 conference in Munich with their Think Big campaign.

The focus was less on directly recruiting young people into vocational fields, and more about showing them how the industry has developed and the advanced technology that has changed the landscape of the day-to-day construction career.

Another company that is doing a great job of demonstrating usefulness and creativity is Caterpillar.

Caterpillar made waves last month when they released a video that went viral of five of their machines playing the world’s largest game of Jenga.

They were at it again recently, releasing this clip of an operator expertly maneuvering a 301.7 CR mini excavator around a China shop that Caterpillar created special for the video.

Equipment world called the video one of the most impressive displays of operator skill they’ve seen.

The video lasts less than two minutes and shows Ryan Neal, a senior demonstrator instructor at Cat, carefully using the bucket of the machine to transfer a glass onto the top of a pyramid champagne of glasses.  
This type of video is a great way to demonstrate both the unique experience of operating this type of equipment and also the extreme functionality that the equipment can provide their customers.

While it is doubtful that many construction companies will be erecting champagne pyramids, excavation projects or trenching around utilities in urban areas are both situations where precision and control are premium qualities. 

In addition to demonstrating the valuable qualities of the machine, the video also conveys the many advantages there are to devoting sufficient time to train your workers on these advanced machines so they have the ability to operate them as efficiently as possible.

Investing in your employees training will make advanced machinery even more beneficial to your company and you will run more efficiently than ever.

If you are about to start a job that requires precision and control, a mini excavator could be a great piece of equipment. If your next project involves trenching, tunneling, or excavating our wide selection of cutterhead attachments could provide you with even more control over your operation.

The more control you have, the more confident you can be in the results you expect to produce.

Find out everything you need to know about rock grinding with a cutterhead


Topics: Excavation, Construction

3 Tips for Excavating a Foundation with a Rockwheel

Posted by Ryan Leech

May 26, 2014 7:30:00 AM


In a competitive industry such as construction, every detail matters.

This makes the planning and evaluation process so crucial. Construction teams do diligent work on the front end to evaluate the specifications of a project and submit a competitive bid.

By accurately determining the tools necessary to complete the job, companies take an important step towards setting themselves up for success.

A company that submits a winning bid has obviously done the requisite research to put together a viable plan, so what is the difference between successful and unsuccessful projects?

In any construction project, one of the most critical components to being successful is time.

Seemingly inconsequential details can drastically change the nature of a project by creating time-killing delays or by increasing efficiency.

This is especially true for excavation projects.

There are several reasons that using a RockWheel will provide you with a performance advantage over competing tools, but simply choosing to use a RockWheel will not make your project as efficient as possible.

Here are three tips for excavating a foundation with a RockWheel that will improve your efficiency and cut down on unnecessary delays.

Pay Attention to Operator Form

Ensuring that your operator understands the best way to operate a RockWheel will create a better, more consistent rockwall that will improve the quality of the operation.

Proper technique will also allow for a cleaner precision cut.

Precision cut footers or foundations mean less money spent on over breaking, rock crushing and backfill.  

Giving operator form the attention it deserves will save time and money.

Plan Out the Best Procedure

Since getting the best vertical walls will take some excavator maneuvering, it is important to plan out your procedure.

If you just start operating without planning your movement, you may start creating an uneven wall. Without the proper strategy, it is easy to create a situation that cannot be easily corrected.

By failing to create a proper game plan you will end up using more time correcting situations that could have been entirely avoided in the first place.

If you can identify the maneuvers you will have to perform, you can adjust your worksite to make those movements as fluid as possible.

This can be done by moving equipment and other objects to ensure the necessary pathways remain open.

Plan Muck RemovalJG_Rents_demo_023

Equally important to excavating the material is having a process in place to remove the excess excavated material.

The great thing about using a RockWheel is that this material will be finely crushed and can often be used as backfill directly on site.

Instead of the large, uneven chunks that are the result of using hammers, the excavated material of a RockWheel does not need to be transported.

This eliminates an expense from the project and it also saves valuable time, which will help meet deadlines.

Removing muck is a simple step in the project that is easy to overlook, but neglecting to have a process in place beforehand can result in a costly halt in production.

To prevent any unnecessary delays, detail a muck removal plan that can be implemented immediately following excavation.

By implementing these three tips you will get the most out of your RockWheel and take a big step towards becoming more productive and efficient.


Find out everything you need to know about rock grinding with a cutterhead



Topics: Excavation, Rockwheel

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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