Compared to wheels and its skid steer cousin, a track loader’s dedicated undercarriage gives it added weight, traction and balance, making it great in dozing operations. On a construction, landscape or ag project, dirt work is an aggressive and rugged application that requires pushing, digging, loading and sometimes extreme precision.
Compact track loaders (those tool carriers that look like skid steers but have tracks instead of wheels) are gaining popularity with contractors specializing in dirt operations. Rolling onto a jobsite like a tiny tank, compact track loaders can spearhead earth works (excavating, grading, site prep or load-and-carry applications), with dirt beneath the blade, soil stuck to the tracks and muddy sod sitting in the bucket.
When it comes to site preparation specifically, compact track loaders are maybe the smallest, most productive precision grade machines on the market. All you need is the addition of a machine control system. Attach a grading attachment, equipped with masts, lasers, a control box and maybe a global positioning system (GPS) or universal total station (UTS) system, and you can control elevation and grades with an accuracy of ¼ of an inch.
“Trimble’s grade control systems for compact loaders and their attachments show very high value in any surface prep work prior to concreting or paving,” explains Scott Crozier, director of marketing for Site Positioning and Machine Control in Trimble’s Civil Engineering and Construction division. “We see it utilized a lot for sports facilities projects and in residential and commercial construction, specifically for fine grading work for footpaths, car parks, subdivisions, large building pads, inner city road works, horse arenas and tracks, sports fields, golf greens and tee areas.”
Trimble is one of many brands and players in the grade control arena — for both big and small construction equipment. Trimble offers its own 3D GPS and UTS machine control solutions for a range of compact track loader attachments. Trimble offers products for a lot of the popular players too — the Bobcat HD Grader, ATI Level best box blade, Hitch Doc box blade, Yelton box blade and the Spektra SK200 box blade.
In fact, the Trimble GCS900 Grade Control System can provide manual and automatic control for almost any compact track loader grading attachment in the industry.
The compact track loader itself is a utility machine, which means it can shift, change and adapt to your specific dirt operation using its regular-flow (19- to 23-gpm) or high-flow (up to 40-gpm) hydraulic attachment system. Some of the improved productivity in a track loader can be traced to the loader’s operating weight when using these implements. The extra weight allows the machine to have higher pushing forces, so compact track loaders particularly excel at grading applications.
Attachments such as dozer blades, graders, box blades, landplanes, soil conditioners and landscape rakes are great choices for owners who have this dedicated track machine in their fleet. When it comes to precision grading:
“The size of the track loader required depends on the size of the attachment,” says Crozier. “Typically, we see loaders of greater than 70 hp used with grading attachments. Loaders with greater than 100 hp are becoming more common, and we typically see these machines using the larger grading attachments with some form of machine control solution on them.”
Machine Control Solutions
Compact track loader owners with precision grading attachments using machine control solutions will see a big bump in productivity. Finish grading attachments such as the box blade, landplane or landscape rake already benefit from the track loader’s lower ground pressure. The loader’s flotation helps reduce the impressions or marks caused by the machine to the soil or subbase for a smoother surface when the project is finished. Add a machine control solution for grading, and it’ll mean even less rework, less staking, lower operating costs, improved material usage and faster job cycles. In fact, the most high-tech systems can even display point data, machine diagnostics and jobsite progress live from the field to an office computer. For starters, there are various grader attachment sizes.
“HitchDoc’s bi-directional Dual Dozer offers sizes of 6-, 7- and 8-ft models,” explains Chad Mohns, vice president of sales and marketing with HitchDoc. “All models come ready with standard plug-and-play sensors. This makes it easy for owners to choose and switch between lasers, slope sensor, sonic, GPS or UTS. There are a lot of various applications for our machine, and we’re geared to keep it as simple as possible for the end-user. Our base models start under $15,000 and go as high as $80,000, with 3D sensor capability. However, our base models can be upgraded with new and different electronics after many years of service. The owner doesn’t need to be concerned with the base model being outdated as fast as the technology evolves.”
Like the Dual Dozer, there is a good selection of interesting systems on the marketplace, utilizing GPS, 3D, UTS or just laser systems to provide distinctive levels of accuracy and price point. Bobcat offers three solid systems when it comes to precision grading attachments. For the lowest price point, Bobcat offers its laser guided system: A laser transmitter is used to emit a plane of laser light across the jobsite. The plane mirrors the completed jobsite and is used as a reference point to ensure the blade is on-grade at all times. The blade moves up and down automatically to keep the base materials on-grade. Laser transmitters and rod-mounted laser receivers can also quickly determine the amount of material that needs to be added or removed from the site.
“On the jobsite, the laser transmitter is mounted on a tripod to provide a 360-degree plane of reference at a set elevation and slope,” explains Jason Archbold, marketing manager with Bobcat. “Laser receivers, mounted on a mast attached to the box blade or grader attachment, capture the light from the laser transmitter. In manual control mode, the receivers inform the operator via LED lights when the blade needs to move up or down or to notify that the blade is on grade. In automatic control mode, the receiver informs the blade that it needs to move up or down to stay on grade. With the box blade attachment, one receiver — mounted in the middle — moves the entire blade up or down. With the grader attachment, two receivers are mounted so that each side of the blade will adjust independently.”
Moving up in tech and size, Bobcat also offers a sonic/slope tracer system for its larger grader attachments. Whereas the laser-guided systems require a laser transmitter and can only follow a plane of light, the sonic/slope system will follow the terrain below the sonic tracer (mounted on one side) and maintain a consistent cross-slope that has been predetermined. This system works well on jobsites in which the transmitter may not have complete visibility to the receivers at all times. Sonic/slope systems have three main components:
- Sonic tracer: Controls the elevation of that side of the moldboard.
- Cross-slope sensor: Mounted to the back of the moldboard to maintain a set cross-slope on the opposite side of the moldboard.
- Deluxe instrumentation panel: Used as a control box to operate the system.
Of course, Bobcat’s most high-tech piece of equipment would be its 3D-ready system. Using GPS or UTS, the system has the ability to complete complex design projects including parking lots, sports fields and road work.
“Users have the ability to choose between a satellite option for outdoor applications and a universal total station option for indoor applications,” says Archbold. “After a computer-generated model is loaded into the loader’s control box, the system automatically grades the ground with remarkable accuracy. With the 3D-ready system, the office and jobsite are brought together. To set it up, a user simply loads a software-generated model file to the CB450 control box. The loader will take care of the rest. Job progress can be monitored from the office using our Connected Site software. It also gives the ability to make updates to designs, wirelessly loading the new model file to the loader on the jobsite in real time.”
Remember that 3D systems will also require the use of software to process and create a digital model for the grade work.
“Our system will require a 3D digital design or terrain model to be created,” explains Crozier. “The models can be created in many design software packages including Trimble SketchUp or Trimble Business Center. Trimble Business Center will then export the design with a local calibration file in a format optimized for machine control performance. The file can be loaded on the control box over the air through Trimble’s Connected Community service or via a USB stick.”
The cost range for these systems is pretty significant, going up to $80,000, depending on size and tech. That includes both the attachment ($10,000 to $20,000) and grading system ($25,000 to $50,000). Installation of a grading system’s base-level components such as mounting brackets and harnesses to the machine and attachment are often installed prior to delivery to the customer, with no additional welding, drilling or re-painting required. Systems on the compact track loader may include the addition of a control box, sensor kits, harnesses and perhaps an extra monitor for the cab. Most systems only need a 12-volt power and hydraulic source from the machine.
“The Trimble GCS900 system is installed on the attachment and loader in less than eight hours,” says Crozier.
“In the case of the Trimble Ready attachments like Bobcat’s HD Grader, the system can be installed and up and running in less than four hours, including machine set up and valve calibration, which ensures optimum grading performance.”
Compact loaders offer a light footprint with extreme traction for finish work in dozing applications versus conventional wheeled machines. Contractors can’t go wrong with lasers if they are doing flat/sloped subgrades, parking lots or sports fields. GPS and 3D systems are great on uneven finished terrain, yet are able to do flat/sloped work, as well. These amazing systems can actually automate the blade attachment, taking precision grade work out of human hands. Of course, the operator still needs to steer the machine, manage the material flow by rotating the blade and set the design offsets correctly to ensure the machine is not pushing more material than it is capable of. Like any grading job with large cuts, it’s important to understand your machine, technology and your target design elevation.
“Actually, there is very little training required,” says Crozier. “On receipt of the system, a SITECH [Trimble’s global dealer network] representative can have an operator trained within 15 to 30 minutes, getting them comfortable with operating the system, utilizing its core functionality.”
Keith Gribbins is associate publisher of Utility Contractor.