September October, 2004




Mulching Toward Healthier Forests 

Rotary disc mulchers used to decrease fires and improve habitat

By Kurt Glaeseman

Mixed species before the mulching and thinning operation

With today’s specialized forestry issues, technology that promises better service and performance will invariably get second looks at equipment shows and field operations. The rotary disc mulchers offered by Advanced Forest Equipment are certainly collecting their share of ribbons. The RDMs (rotary disc mulchers) are proving useful and efficient in fuels reduction, planned thinning, brush chopping and general clearing of gas and electricity easements. It’s mastication at work!

Creating the Ideal RDM
Jon Moffet, of Hayden, Idaho, spent five years designing and perfecting the mulchers, which are manufactured in Idaho but are also available in Eugene, Ore. The RDMs come in two different series — one for use with an excavator and the other with a skid steer. Compact enough to tow behind a pickup, the RDMs are portable and can be moved quickly for the first pass, a blow-and-go attack that will break down 15-inch trees into debris no larger than 4 foot by 3/4 inches. If specs call for a less ragged look, a second pass will result in finer chips and a more manicured finish. Ryan Mallery is a regional supervisor for Environmental Forestry, Inc., sometimes referred to as EFI. He loves working with the mulchers and training others to work with them. Both his grandfathers worked for Weyerhaeuser, and Mallery admits that logging is in his blood as well. Of course the technology has changed, but he actively enjoys the 10-12 hour days, often seven days a week.

315C CAT Excavator with Rotary Disc Mulcher made by Advanced Forest Equip.

Training a good crew
Mallery grew up near Caldwell and Coeur d’Alene, where he learned to run a skidder, a danglehead, and various strokers. He is always on the lookout for additions to his crew, but he insists that they have some logging background and are willing to work hard. “It’s actually difficult to find qualified guys who can be trained as operators,” says Mallery, “even though we hear a lot about high rates of unemployment.” He chuckles a little as he remembers his own first years: “I’d better not be too hard on the new guys. I tipped over a skidder for my first logging boss, and he didn’t fire me. He was convinced that I had potential, that I could make it in logging.” His crewmembers tend to be from Idaho, even though he is running two operations in California, down near the south end of Highway 49. Mike, Scott, Curtis and Lance are all loggers or ex-loggers, willing to give long hours to a job that demands attention to detail, perseverance, and just plain hard work.

Ryan Mallery, Supervisor for Environmental Forestry, Inc.

EFI is working with brand new Cat equipment, so there is no shop or yard. The crew lives out of campers or trailers and travels from job site to job site. Mallery does the employee hiring and training. He looks for guys with a logging background, people who understand the woods and know the different species of trees. The first several days he asks the new guy just to watch — how he takes down trees, how he cuts brush, how he positions the Cat on varying slopes. When the novice actually runs the machine, Mallery follows up, putting ribbons on anything that does not pass specs. At this point Mallery feels it is not necessary to involve the Forester. “We’ll clean up any errors and soon get the guy on a 90 percent compliance rate. Of course we’ll push for 100 percent! When the Forester checks our progress, we want to show we are professional, to show something we are proud of.” Mallery admits that he is a perfectionist: “When I see a wall of brush, I want to make a park out of it. I want to make a difference, a good difference.”

Above: Scott Fairchild, Operator, ready for work.

Thinned, mulched and safer
This California job outside of Oakhurst is for the Sierra National Forest, whose plan calls for fuels reductions and urban interphase requirements that make it easier to keep fires away from homes and buildings. Targeted trees are from 12 inches to 20 feet high (over the cab!) and may be from one inch to 12 inches around. The area is currently too thickly treed; specs call for 15 x 15 or 17 x 17 foot spacing. The operators make the decisions about which trees to take —diseased trees, trees with forked tops, trees with heavy mistletoe. The variety includes manzanita, buckbrush, ponderosa pine, cedar and other miscellaneous brush. Wild lilacs are generally kept, and of course riparian zones are respected. What starts as a brushed-over area soon develops into an evenly spaced park-like forest. No limb longer than six foot and no stump higher than 12 inches can be left. The thinned and mulched area has some definite benefits:
• Forest fires are easier to control, since the fires tend to stay on the ground rather than leap to the tops and crown.
• Water is absorbed by the mulch and remains longer for the soil to utilize.
• The mulch salvages nutrients that can go back into the soil.
• Wildlife habitat is enhanced with variable growth stages.

The Rotary Disc Mulcher at rest.

Challenging terrain
The basic terrain in this part of the Sierras can present some difficult problems, but Mallery has found that the Cat 315 and the 9044 Excavator Series can get the job done. On the Oakhurst job the maximum slope is 35 percent, but at some job sites it is higher — up to 63 percent. “We have the capability with the thumb and spade on the back of the mulcher. The spade goes into the ground and gives stability and allows the head to pull up stumps or pick up logs or rocks. The slopes aren’t much of a problem unless we get a lot of snow — you can’t mulch brush under five foot of snow!” Tom Wright, the Advanced Forest rep in Eugene, is always willing to answer questions, but he often defers to Mallery’s in-the-field enthusiasm. As Mallery points out, the application of the rotary disc mulcher is a new concept, designed specifically for today’s forests. Like the word “mastication,” the RDMs have become a vital part of the present-day logger’s working vocabulary.


9034 SS & 9044 EX

The RDMs are complex and versatile yet user-friendly. The 9034 SS (Skid Steer) series has a complete boom mounting system and can use existing carrier and hydraulic flow and controls. The full reduction shroud guarantees safety and uniform mulching. The top and side teeth—heat-treated beaver teeth—are easy to replace, and the carbide bottom teeth are rock resistant. A strong feature is the oilbathed, high speed, high shock-bearing box.

Total weight of the head and boom assembly — 1800 pounds. The 9044 EX (Excavators) Series is designed for 12, 15, and 20 metric ton excavators. It too uses existing carrier hydraulic flow and controls, and it features the full reduction shroud. It has the same top, side and bottom teeth and the high shock-bearing box. Added are the spade feature for low impact maneuverability, the wedge locks for quick changes, and the ability to work with factory thumbs. The total attachment weight — from1600 to 2200 pounds.


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This page was last updated on Saturday, November 20, 2004