The Missoula Equipment Development Center (MEDC) has developed a miniyarder that is making it possible to cost-effectively yard light slash, thinnings, and small stems from steep slopes, This small yarder operates on terrain and soils that may prevent conventional ground skidding or where larger cable systems are inefficient and uneconomical because of the materials' small size.
MEDC developed this yarder concept for the Bitterroot National Forest. Bob McKee, fire management officer on the Darby Ranger District, wanted a small yarder that could cost-effectively reduce the fire hazard while making residues available for firewood.
"The Bitterroot Miniyarder gives us an alternative to burning," McKee says. "Because we have this machine to clear slash, it becomes another factor we consider when laying out timber sales."
The Bitterroot Miniyarder is a compact, two-drum skyline yarder that weighs 1,600 pounds fully rigged. Despite its size, it can pull 2,000-pound loads at line speeds of about 160 feet per minute, with a maximum line speed of 400 feet per minute. McKee says in heavy slash concentrations he can skid a load-typically three pieces measuring 8 inches by 16 feet-to the landing every 3 minutes with this miniyarder.
"Anyone who has been involved with this machine on the Bitterroot is convinced it is here to stay," he says. "It's easy to set up, cheap to operate, and has proven maintenance free."
This miniyarder mounts easily in the bed of a ¾-ton pickup truck or on a trailer. And it is light enough to be transported by helicopter. It can also be put on skids and towed or self-skidded, or can be mounted on a frame with tracks to propel itself.
The yarder's rugged construction and simple operation allow regular forest crews to operate and maintain it.
The miniyarder is small and efficient. It requires a minimum crew of two and uses lightweight; 4-inch cable. This, combined with its mobility and simple set up, make the Bitterroot Miniyarder an easy-to-operate machine.
Currently, Bitterroot Miniyarders are operating on National Forests in Montana, Oregon, Idaho, Alaska, and the South. The Alaska unit is designed to be disassembled and transported by small airplane or riverboat to remote areas.
Parts and materials for a fully rigged Bitterroot Miniyarder cost about $7,500. A complete set of fabrication drawings is available; request drawing MEDC-718. Persons interested in this miniyarder can obtain more information from MEDC. Write or call:
USDA Forest Service
Missoula Technology and Development Center
5785 HWY 10 West
Missoula, MT 59808
(406) 329-3900
- Can be built in small shops.
- Uses many commercial parts.
- Rugged, low-maintenance design.
- Compact, lightweight, easily mounted on ¾-ton pickup, trailer, skids, or tracks.
- Helicopter transportable.
- Rapid, simple set up.
- Easily operated by regular forest crews.
- Lightweight cable reduces crew workload.
- Hydrostat lets operator use maximum engine horsepower on every turn by balancing line speed with pull for top efficiency.
- Mechanical controls permit simple, dependable operation.
- Remote controls improve safety and operator view of operation.
- Double drum with independent brakes; mainline clutch for free wheel operation.
- Fairlead has double block sheave with roller bearings and swivel.
- Adjustable angle A-frame boom.
- Live skyline.
- Fuel-efficient engine.
Weight: 1,600 lb rigged
Engine: 18-hp Briggs & Stratton, twin cylinder, air cooled, electric start; remote fuel tank
Transmission: Sundstrand series 15 hydrostat
Axle: Dana Spicer GT -20 with n-tooth spur gear
Skyline & Mainline Drums:
800 ft of 14-inch cable
0- to 2,000-lb line pull
0- to 400-fpm line speed
Mainline Clutch: Dog type
Brakes: Band type, mechanically operated, 12-3/5-inch diameter
Boom: 2½-inch pipe A-frame, 17½,-ft long, 180o fairlead swivel, manually raised and lowered
Controls: 15-ft mechanical push/pull cable
For additional information contact MTDC:
USDA Forest Service
Missoula Technology and Development Center
5785 Hwy. 10 West
Missoula, MT 59808-9361
Phone: 406–329–3900
Fax: 406–329–3719
Electronic copies of MTDC’s publications are available on the Internet at:
http://www.fs.fed.us/eng/pubs
Forest Service and Bureau of Land Management employees can search MTDC’s documents, CDs, DVDs, and videos on their internal computer networks at:
http://fsweb.mtdc.wo.fs.fed.us/search/
