April 2005 - The Logging and Sawmilling Journal
Beefing up the Deere
Alberta’s C & C Isley Logging is seeing first-hand how John Deere has improved its shift-tilt feller buncher, including beefing up the entire shift-tilt leveling mechanism with more steel.
By Tony Kryzanowski
The next generation of one of Alberta’s premier logging families—the Isley’s—has taken on the task of conducting the acid test on a new generation of feller bunchers with John Deere’s patented shift-tilt leveling technology. Now that the technology has been on the market since 1999, John Deere has had ample opportunity to identify any weaknesses in this four-way leveling system that is essentially unrivaled in the industry due to its uniqueness. While they are capable of performing equally well on level ground and on steep slopes, it is on extreme slopes where feller bunchers with shift-tilt technology really deliver value for the extra investment. C & C Isley Logging of Grande Prairie, Alberta, is owned by brothers Cory and Celsy Isley. They recently purchased a John Deere 759G feller buncher with zero tail swing and shift-tilt leveling technology. In addition, the company also operates John Deere model 853 and 903 feller bunchers, and a 748-GIII skidder.
They sub-contract their harvesting and skidding services to D & J Isley and Sons Contracting Ltd, which is Alberta’s largest logging contractor. Owned by Roy and Morgan Isley, the company harvests about 850,000 cubic metres of softwood and hardwood annually. Some of that timber, destined for Canfor’s mill in Grande Prairie, is on extremely hilly terrain in the Rocky Mountain foothills near Grande Cache.
Roy’s sons Cory and Celsy have the responsibility of harvesting that timber and have opted for a shift-tilt leveling feller buncher. Of the 350,000 cubic metres they harvest annually, about 100,000 cubic metres is on steep terrain. Cory says the slope can reach as high as 65 per cent in the Grande Cache foothills, where feller bunching is essentially the only mechanical option to harvest the wood. The terrain is not suitable for a high lead system because the landscape has too much pitch to obtain proper deflection. “The 759G gives us access to ground that we couldn’t have accessed without a tilter,” he says. “Using shift-tilt leveling technology is definitely a safer option to logging that ground versus other tilters. Your weight is shifted to the front of the machine, so you will actually stick to the hill and sit there.”
He adds that the 759G is also the right machine size for the timber in that area, which is typically in the 15-inch diameter range.He is helping to provide input on what initiatives the government can put in place to assist the industry. Lemay is a member of the government of Alberta’s Secondary Manufacturing Advisory Committee. “We’re in the middle of doing a study with the Alberta government to see what the drivers and detractors will be for the secondary manufacturing industry for the next 10 to 15 years,” Lemay says. Two of the more immediate issues that are impacting growth and development within the secondary manufacturing sector are the ongoing softwood lumber dispute with the United States as well as the rising value of the Canadian dollar.
While any operator can learn how to use a feller buncher equipped with this technology, Isley emphasizes that it is important to have an experienced operator working in an environment with extreme slope. The method C & C Isley Logging uses is to start harvesting logs at the bottom of the hill and then follow a path up the hill. To maintain a safe working environment, the operator walks the feller buncher back down the hill and starts harvesting logs from the bottom up all over again. “Shift-tilt leveling works well in this application because the feller buncher is designed to tilt forward and cut up the hill,” says Isley.
What’s important from a productivity standpoint is to equip the feller buncher with a high rotation head because of the different angles that it works at poised on the side of a hill. “We have a felling head that will essentially flip upside down,” says Isley. “Over the course of a year, we build a lot of bridges. Having a high rotation head is great for maneuverability in both unfavorable ground and for building bridges.”
This is the logging company’s second feller buncher with shift-tilt leveling technology, having put an older 753 feller buncher with an earlier version of this technology to extensive use on extreme slopes. The company also worked with a prototype of the new 759G. Isley says there are many noticeable improvements in this new model. For example, John Deere has beefed up the entire shift-tilt leveling mechanism with more steel, making it a lot stronger. It has also switched to a different bushing style. “We did have some breakage in the structural design of the older 753 model,” says Isley, “but it wasn’t extreme.
Some of the components just needed improvement and John Deere has done that.” Among the improvements that John Deere lists on the 759G are: heavier and stronger structural components; adjustable side clearance of links; improved serviceability and lubrication; heavy guarding for all critical components; and an improved rotary manifold for increased reliability and durability. Also, the cab is now both wider and taller, with isolation mountings to reduce noise and vibration for a more pleasant operating environment. Isley agrees that the cab is much more comfortable. “With most of the bunchers I’ve operated, you are usually sweating in your upper body while your feet are frozen,” he says. “This 759G is the first buncher I have ever run where your feet are warm. They’ve put venting all over so that it is much easier to regulate the heat in the cab.”
There is also more padding around the cab’s steel structural components, which contributes to noise abatement. One additional bonus with shift-tilt leveling is that even on lesser slopes of 10 to 15 per cent, the operator is able to work in a level position, which helps reduce operator fatigue. Isley expects to achieve more productivity from the 759G because it has more horsepower, more lifting capability and responds faster. However, he has just put the unit into production so it is too early to tell just how much more it will deliver. He says he has noticed that the 759G burns about the same amount of fuel as the older 753 model.
The 759G is powered by a Deere model 6081H, 241 horsepower, 8.1 litre Tier II engine that provides 4.8 per cent more horsepower at 2,000 rpm. How the shift-tilt leveling system works is that the upper structure shifts forward in direct proportion to the slope’s grade. It is a four-way leveling system that can level 27 degrees forward on 51 per cent slope, 20 degrees to the side on 36 per cent slope, and 10 degrees to the rear on 18 per cent slope. Complementing its leveling ability is 360-degree continuous upper rotation.
Shift-tilt leveling technology was originally adapted to forestry use by Timberjack design engineers from a basic concept used in agricultural applications. John Deere now owns Timberjack. Engineers wanted to find a way to better manage the centre of gravity on zero tail swing feller bunchers, increase productivity, and enhance stability while harvesting on hillsides. By repositioning the engine, fuel tank, hydraulic tank and components to achieve zero tail swing, this created the problem of moving the centre of gravity forward considerably in relation to the felling head. This was particularly problematic if a zero tail swing feller buncher was perched on the side of a hill and swung around to the side or back to set down a tree. The centre of gravity would sometimes move twice the distance ahead of the centre of rotation.
The challenge was to find a leveling system that kept the centre of gravity in an optimal position whether the load was facing forward or backward. The only way that could be accomplished was if the upper could be shifted relative to the tracks. Timberjack’s design engineers discovered a four-bar linkage system developed by two United States Department of Agriculture employees. It was based on the principle of using unequal length front and rear links. As the twin tilt cylinders extend, the upper tilts and moves forward, relative to the tracks and to the hillside, thus moving the centre of gravity more toward the hill and creating more stability.
Luckily the US patent on this technology expired, allowing the engineers to develop a system for use in forestry. Suffice it to say that when shift-tilt leveling technology arrived on the market, loggers faced with harvesting logs on steep slopes liked the concept, but had concerns about wear and tear on all the moving parts. Isley says what made it easier for him to initially try and then continue using this technology was the parts and service support from John Deere dealer, Brandt Tractor. “We shopped around a bit for a tilter, but we stuck with John Deere because we liked the product and Brandt Tractor looks after us exceptionally well,” says Isley. “In my opinion, their service support and personnel are second to none. All of our machinery is John Deere. It kind of works both ways. We get the service support and they get our business.”
This page and all contents
©1996-2007 Logging and Sawmilling
Journal (L&S J) and TimberWest Journal.
last modified on
Thursday, June 16, 2005