Workhorses of the Woods

The Big Four equipment manufacturers in the forest harvesting space discuss product offerings and technological advancements to improve emissions, operator comfort and safety, productivity and efficiency.
By Ron Kotrba | May 20, 2016

Certain terrains, smaller timber tracks and larger tree diameters still call for chainsaw-wielding lumberjacks to fell trees, but an increasing number of forestry operations today are run by operators of heavy machinery used to fell, cut, skid, forward, process, load and transport wood. These machines are the stuff little boys dream of. Hulking, dauntingly powerful, cool-looking and even cooler-named forestry equipment are the most uniquely designed and specialized heavy-duty vehicles around.

By all accounts, the four major equipment providers in this space are John Deere, Caterpillar, Komatsu and Tigercat. Biomass Magazine talks forest harvesting equipment with each of them to paint a picture of what the sector looks like, and what advancements have been made in recent years.

Although a myriad of site-prep tractors, bulldozers, loaders, excavators and other machines such as knuckle booms and dangle head processors are integral to forestry operations, what are considered perhaps the most ubiquitous, specialized machines in the field are feller bunchers, skidders, harvesters and forwarders.

A harvester is a self-propelled machine with a cutting head attachment that is used to fell and process—or delimb and buck—trees in cut-to-length operations. Harvesters come in track or wheel configurations, and which one is preferred depends on the terrain. Caterpillar makes track harvesters, according to Antonio Solano Jr., the global commercial manager for Caterpillar Forest Products, while Steve Yolitz, forestry marketing manager for Komatsu America Corp., says Komatsu manufactures cut-to-length wheeled and track harvesters. Mike Schmidt, the forestry tactical marketing manager for John Deere Construction and Forestry-North America, says track harvesters are better-suited for soft, wet ground because they exert less pressure per square inch on the soil, and track equipment is safer on steeper slopes. “Operations are trying to get away from hand-falling on steep slopes because it’s dangerous,” Schmidt says. “Some even use track harvesters on slopes that are tethered by a cable to a bulldozer with a wench.”

Yolitz says Komatsu also provides a broad range of harvesting and processing head attachments designed for everything from thinning to final felling applications.  “This includes heads with multistem harvesting capabilities for thinning projects and heads that excel in the recovery of wind-blown timber,” he says.

A feller buncher is self-propelled with a cutting head designed to hold more than one tree at a time. Unlike a harvester, most feller bunchers are used solely for cutting, holding, and placing whole felled trees on the ground, and they do not have the ability to process. Wheeled feller bunchers are sometimes called “drive-to-tree” and have the cutting head mounted directly to the carrier without a swing boom, whereas track feller bunchers are boom-equipped and do not have to drive to each tree to fell. While a feller buncher is typically used only to cut, hold and place, Yolitz says Komatsu’s XT-3 series machines can also be equipped with a harvesting head and perform cut-to-length harvesting and processing.

“Komatsu’s XT-3 Series track feller bunchers are for tree-length logging, and offer an automated four-way leveling system for maximizing operator productivity while operating on sloped or rough terrain,” Yolitz says. “Models feature a state-of-the-art cab with dramatic widescreen visibility and first-in-forest use of the advanced IQAN-MD4 control system.” Models include the nonleveling XT430-3 and the cab-leveling XT430L-3, XT445L-3 and the largest XT-460L-3.

Skidders are typically used to drag whole, felled trees to a landing or roadside with either a cable configuration or grapple, or both. Schmidt says they also help keep the landing clean, as most have front blades used to push material away and take limbs from the processing area at the landing back out to the forest to be spread out. While most skidders are wheeled, there are some track skidders that are either custom- or purpose-built. A skidder takes piles of trees left by the feller buncher and brings to processing at the landing.

Forwarders operate in conjunction with a harvester to haul cut-to-length logs processed in the woods to the landing. Typically they are wheeled units with a cab, a bunk for hauling and a grapple to load and unload material.

Technological Advancements
Ongoing improvements in the forest harvesting space have focused on lower emissions to meet stringent regulations, better safety, increased efficiency and productivity, and greater operator comfort.

“Komatsu was the ‘first in the North American forest’ to offer a complete line of harvesters with powerful, fuel-efficient Tier 4 Final engines,” Yolitz says. Tier 4 emissions standards for off-road diesels, implemented by U.S. EPA in the past few years, significantly reduce allowable levels of NOx, particulate matter (soot) and hydrocarbon emissions. Tigercat’s international factory sales representative Gary Olsen says, “The biggest challenge for all forestry equipment manufacturers over the past couple of years has been complying with the new Tier 4 environmental emission level requirements.” Though manufacturers of diesel equipment utilize many different configurations to meet the new standards, Olsen says Tigercat has tackled this challenge through teaming up with FPT Innovations to develop an engine series that meets the stringent requirements without the need for a variable geometry turbocharger, an exhaust gas recirculation system, a higher capacity cooling system, an intake throttle body or a diesel particulate filter (DPF). “No ‘regens’ are required,” he says, referring to regeneration of a soot-loaded DPF. “In addition, the engine series offers proven reliability and lower long-term maintenance costs. Most of the new emission equipment is found in the exhaust or aftertreatment system. The key is the selective catalyst reduction (SCR) system, which converts the harmful components of the exhaust gas stream into water, nitrogen and carbon dioxide.”

Caterpillar’s new engines not only meet the more stringent EPA standards, but Solano says they are also more fuel-efficient and productive. “Operating modes that give the logger the choice of running a machine for maximum fuel economy or maximum power are another example [of how technology is advancing],” he says.

Logging companies are saying it’s getting harder to find labor, Schmidt points out, so forestry equipment manufacturers are charged with making their machines capable of doing more while providing greater safety and comfort to the operators. “The Komatsu 855.1 forwarder is available with the advanced ‘Comfort-Ride’ hydraulic cab suspension system option, which effectively dampens the bumps and jarring effects of rough terrain normally felt by the operator,” Yolitz says. “This four-point cab suspension system is more effective than other three-point systems.”

As Caterpillar continues to focus on safety, the company has delivered what it calls an Operator Safety Fatigue Monitoring system. “This creates an operator awareness and reduces the risk of fatigue,” Solano says. “Also, our ergonomically friendly cabs contribute to operator comfort. This allows our customers to get more out of their equipment.” Caterpillar Forest Products is also introducing a seat suspension technology for D Series wheel skidders that Solano says will provide unmatched comfort for operators and help improve the bottom line for logging contractors. “The Cat Advanced Ride Management seat suspension system is a semiactive suspension that dampens vibration and minimizes end stop events, significantly improving operator comfort,” he says. “Semiactive means the suspension can adjust the rate of damping in real time—a breakthrough technology.”

John Deere recently released innovative software technologies for its forest harvesting equipment: TimberNavi and JDLink. JDLink transfers information between the customer and the dealer to identify and preempt any problems developing in the machine, Schmidt says. Before the problem causes downtime, Schmidt says they can get in front of it and prevent more significant damage. “That technology is pretty new and evolving rapidly,” he says. TimberNavi allows monitoring locations of machines in real time to optimize operations. “It provides information, and the more information you have, the better your decisions can be,” Schmidt says. For instance, a job can be structured to use the same skid trails to reduce impact to soil on a particular parcel; or to predict volume and schedule trucking.

Caterpillar also utilizes telematics, or technology that uses wireless communications and GPS tracking, to monitor and manage equipment. “This technology is underutilized in the logging community now, but will gain acceptance as loggers see what it can do for their bottom line,” Solano says. “With Cat Product Link, customers can more effectively manage their business by, for example, reducing equipment idling time, identifying less productive operators and avoiding catastrophic failures. Cat dealers can monitor their customers’ machines and watch for issues and alert customers when maintenance is due. The system can also ensure operations occur within agreed boundaries to avoid potential liability or sanctions.” Caterpillar forestry machines are even being utilized via remote control for the first time, in a project that Solano says may ultimately may pave the way for wider application of the technology to increase operator safety in the logging industry. “Although remote operation has been used in Cat mining and construction equipment in the past, this is the first use of the technology with Cat forestry equipment,” Solano says.

Tigercat advancements and innovations include TurnAround technology, which allows the operator to drive blade-forward or grapple-forward with full control of all functions. The full speed range and maximum-tractive effort is available in both directions. Its ER boom system technology allows the operator to actuate the boom with optimal hydraulic efficiency, extending and retracting on a horizontal plane quickly and smoothly with a single joystick. Tigercat also reports that its low-wide bunk system is unique to the industry. The bunks are angled to reduce overall gate height and to eliminate the need for a vertical sliding gate.

Solano adds, “Caterpillar has also made significant design improvements in something as simple as the grapple tongs to make it easier to grab more per load, thus reducing the amount of cycles that a skidder needs to go through, increasing productivity and burning less fuel.”

While equipment design, reliability, efficiency and productivity are paramount to customers and operators, virtually all the manufacturers Biomass Magazine talked with boast their dealer network and customer service as top-tiered and second-to-none.

Ultimately, the improvements made to the variety of machines in the forest harvesting space over the years are as varied and wide as the international landscapes on which they operate.

Author: Ron Kotrba
Senior Editor, Biomass Magazine