Clearwater Yarder Operator's Manual , Introduction

Clearwater Yarder Operator's Manual

Introduction

The accumulation of fuels on forested lands, whether by natural causes or man's management activities, creates a potential fire hazard. Many of the most devastating forest fires known to this country started in or were accentuated by logging or thinning slash. Growing demands for wood make harvesting techniques and residues utilization imperative. Terrain and soils or small logs can make traditional yarding equipment too costly to use.

Engineers at the Missoula Equipment Development Center (MEDC) have developed the Clearwater Yarder, a small cable yarding system, to remove slash, dead or diseased timber, and small trees from steep, rugged terrain (figure 1). Even where accessibility is aggravated by small volumes per acre, this yarder is economical because it is relatively inexpensive to build and can be rapidly set up (figure 2).

Photo of the Clearwater Yarder in use.
Figure 1—Clearwater Yarder.

MEDC developed this yarder for the Clearwater National Forest in Idaho. Harry Cummings, fire management officer on the Canyon Ranger District, faced a difficult problem-reduce the fire hazard from slash on c1earcuts that also contain new growth. Instead of destroying the slash-and new trees-by prescribed fire, he decided to yard out the dead wood. After an unsuccessful search for suitable equipment he came to MEDC with his idea and performance requirements for a yarder.

Photo of the Clearwater Yarder in use.
Figure 2—Operating Clearwater Yarder.

This operator's manual contains detailed instructions for the startup, operation, and maintenance of the Clearwater Yarder.

The three-drum yarder weighs only 13,000 pounds, yet can pull loads up to 3,500 pounds and has maximum line speeds of 1,000 feet per minute. It can operate on steep slopes and at yarding distances of 800 feet. Its design meets accepted logging industry safety practices.

Features

Designed to be built in small shops using standard parts.
Design meets accepted logging industry safety practices.
Live skyline.
Easily mounted on a suitable flatbed truck or trailer.
Uphill and downhill yarding up to 800 feet.
Line speeds to 1,000 feet per minute.
Each level-wind winch can be powered independently in both directions, free wheeled, or braked.
Dual axis controller provides mainline and haulback interlock.
Hydrostatic transmissions balance load and speed at maximum engine power.
Remote control operation for safety, improved visibility, and minimum crew size.
Slack pulling capability when operated with Christy carriage.
Designed for rapid, simple setup.
Mast hydraulically raised and lowered.

Specifications

Overall Weight:
13,000 lb fully rigged

Engine:
Ford industrial model LSG-633 P 6 cylinder, 200 cu in, 68 hp @ 2,800 rpm

Hydrostatic Transmission:
Dynapower pumps with Hagglund & Soner wheel motors, 300 rpm maximum

Yarding Distance:
Up to 800 ft

Brakes:
Drum type, hydraulically operated

Skyline:
800 ft of ½-in cable
7,500 lb maximum line pull
0-500 fpm line speed

Mainline:
900 ft of 3/8-in cable
3,500 lb maximum line pull
0-1,000 fpm line speed

Haulback:
1,800 ft of 3/8-in cable
3,500 lb maximum line pull
0-1,000 fpm line speed

Mast:
10-in by 10-in by ½-in wall square tubing
170° fairlead swivel
Hydraulically raised and lowered

Control:
Remote up to 50 ft
12-volt dc electric over hydraulic