THE ULTIMATE GUIDE TO ROCK GRINDING

This comprehensive guide covers every major type of

project that would use a cutterhead, including trenching, tunneling,

excavation, and scaling projects.

ABOUT THE AUTHOR

Ryan splits his time between design and sales at Alpine. He

has a passion for industrial design, furniture building, and anything with two wheels and

peddles. He regularly helps business owners, engineers,

and contractors find the best equipment for their unique

project challenges.

This guide is your go-to resource for everything you need to know about rock grinding, gathered in one convenient location. In The Ultimate Guide to Rock Grinding, you’ll find answers to the most commonly asked questions about cutterhead attachments.

This comprehensive guide covers every major type of project that would use a cutterhead, including trenching, tunneling, excavation, and scaling projects.

OVERVIEW

In the right situation, cutterheads have the ability to greatly improve the effectiveness and efficiency of your operation. This informational resource will equip you with the knowledge you need to make an informed decision based on whether or not investing in a cutterhead attachment would provide a useful return for your project. Keep reading to learn the best uses, attributes, and advantages of cutterheads.

OVERVIEW

TRENCHINGGrinder heads are engineered with consistent dimensions that optimize speed and cutting size capability. The grinder head’s consistency creates smooth, vertical trench walls that leave the surrounding rock mass undisturbed. The vertical nature of the trench walls limits the volume of excavated material, regardless of depth.

Grinder heads provide incredibly precise cuts that enhance the ability to form flat bottomed trenches and improve the ability to control grade. The level of precision that grinder heads allow make it safer to trench around existing utilities and other obstacles.

Each cutterhead will have a slightly unique cutting width, but traditional units will run anywhere from 19” to 55” in width. The cutterhead’s design requires a gear case that leaves a gap, also known as the no-cut zone, in the middle of the drums.

This gap results in an actual cutting width that is a few inches larger than the unit width on the specs. An uncommon but potential alternative is to mount the cutterhead at a 90-degree angle. In this case the cutting width would be the drum radius.

WIDTH OF CUTTER (RELATES TO DESIRED TRENCH WIDTH)?

Cutterheads have the ability to operate at any depth. They’re only dependent on the excavator or carrier machine for reach and depth. Since power remains constant at any depth, the only real constriction is how far the carrier machine can put the cuttterhead into the ground.

It is important to remember, however, that the trench will need to be cleared as debris is cut and builds up. The safe and efficient removal of this debris is an important factor when determining the depth of your trenching project.

HOW DEEP WILL IT CUT?

Cutterheads improve functionality, quality, and efficiency in a trenching operation. Superior cutting precision enables vertical wall trenches instead of the “V-shaped” trenches that hammers require. Cutterheads also ensure consistent, clean walls and smooth bottoms. Over-breaking is greatly minimized compared to hammers, resulting in more stable walls and a highly controlled work zone.

Additionally, the cut rock debris, typically -2 size gravel, is usable backfill that can be applied directly on-site. Converting debris into useable backfill reduces transportation costs and backfill.

ADVANTAGES OF TRENCHING WITH A CUTTERHEAD

EXCAVATIONThe Alpine Transverse Cutterhead’s perfect blend of cutting force and cutting precision make it an ideal tool for excavating soil, rock, asphalt, and concrete. !No matter what your excavation needs are, Alpine cutterheads provide an economical and efficient attachment.

Cutterheads have the ability to operate at any depth, but they are dependent on the excavator or carrier machine for reach and depth.

Since power remains constant at any depth, the only real constriction is how far the carrier machine can put the cuttterhead into the ground.

HOW DEEP WILL IT CUT?

Pick wear is one of the most difficult predictions to make due to all of the potential factors that can impact pick life. Naturally, if the rock is hard and abrasive, the picks will wear down more quickly.

Even the presence of certain amounts of minerals in the rock can also negatively impact pick life. It is very difficult to know exactly how many picks per square yard will be necessary for a given project.

HOW MANY TEETH WILL I USE?

Alpine cutterheads come with a couple key benefits. New cutterheads boast powerful low-speed/high torque capability that is borrowed from underground mining and tunneling technology.

Cutterheads are also equipped to perform precision cuts that create ideal vertical walls, footers, and foundations with minimal overbreaking. The efficient cutting provided by a cutterhead creates reusable backfill onsite, making expensive transportation off-site for further crushing unnecessary.

ADVANTAGES OF EXCAVATING WITH A CUTTERHEAD:

TUNNELINGAlpine cutterheads have a long history of successfully completed tunnel expansions and new tunnel construction. Suitable for almost every condition, from railroad tunnel enlargement to wine cave tunneling, Alpine has the go-to attachment. !With a wide range of rotary cutterhead sizes, Alpine can outfit any of your machines to accommodate small tunnel work with skid steer loaders, Brokks, mini excavators, and backhoes all the way up to large excavators or other hydraulic-ready carriers.

Similar to trenching and excavating, in a tunneling project the reach is dependent on the carrier machine and the ability to clear the accumulating debris as the rock is cut.

The key with these projects is to find an excavator that is small enough, but powerful enough to run a good-sized attachment because tunnels have constraints on size.

HOW FAR CAN IT REACH?

Production rates can vary considerably depending on the size and power of the cutterhead that is being employed and the compressive strength of the rock that is being cut. As a general baseline, the largest cutterheads can offer over 60 cu/yards/hr. in production in soft rock.

Rock compressive strengths can vary greatly so if you would like specific production estimates, we will be happy to deliver if you provide specific compressive strength values for your project.

WHAT PRODUCTION RATES CAN I EXPECT?

Cutterheads can cut virtually all varieties of rock. However, there are some rock surfaces that are impractical for a cutterhead attachment. The effectiveness and rate of production will determine if a cutterhead is worth the investment.

Typically igneous rocks are extremely hard and production rates are low. Shales on the other hand are softer and much easier to cut. Concrete and very weathered rock also tend to make good matches for cutterheads.

CAN IT CUT___ TYPE ROCK?

With proper attention cutterheads can provide great company value by offering low-maintenance utility. Daily checks and drum greasing are simple tasks that will help ensure that the cutterhead continues to operate smoothly. Drum greasing should occur 1-2x daily.

Daily gear oil checks and bolt checks should also be conducted. Finally, keeping your excavator’s hydraulic system clean and free of all dust and other debris is essential for the maintenance of any cutterhead.

MAINTENANCE

Lower start-up costs and flexibility and precision in cutting the tunnel profile are just two of the benefits that Alpine offers companies looking for assistance on tunneling projects.

With the right selection and the proper maintenance, a cutterhead could be a highly efficient tool in tunneling projects.

ADVANTAGES OF TUNNELING WITH A CUTTERHEAD:

SCALINGIn addition to excavating and tunneling, the transverse cutter head can be used for the rehabilitation of sensitive concrete structures such as foundations and bridge abutments and for excavation near lock gates. !When scaling with a cutterhead, the impact angle between the tips of the cutter bits, or picks, and the concrete surface does not exceed 45 degrees. The smooth, low-noise, vibration-free machining action of the bits works ideally because it neither destroys nor causes micro-cracks in the underlying sound concrete. In addition to concrete scaling, several mining operations utilize cutterheads for scaling loose debris after drill and blast operations.

Cutterheads operate at a low speed, only 60-120 rpm, but they have high torque which allows them to operate very efficiently.

HOW FAST DOES IT SPIN?

During a scaling project it is good to have an attachment with the versatility of a cutterhead. With its mix of precision and power, the cutterhead’s rotating action leaves walls consistent and stable while not creating any further overbreaking.

Another unique advantage cutterheads provide is that their drums provide a large area of contact which enables more thorough scaling to occur. These advantages make Alpine cutterheads the perfect tool for your scaling project.

ADVANTAGES OF SCALING WITH A CUTTERHEAD:

We hope you found the information in this guide helpful. At Alpine, we place a high priority on customer service and stand completely committed to helping you find the right solution for the unique conditions of your project.

If you are considering a cutterhead for your next job, contact our team for an expert consultation. With our help, we’ll fit you with the proper cutterhead to increase the quality and efficiency of your next project.

THANK YOU

TALK WITH AN EXPERTIf you’re interested in learning more about expectations, capabilities, and costs associated with a cutterhead, set up a complimentary consultation with one of our experts. !We walk you through the process and help you make the best decision for your unique situation.