The Thunderbird TTY6170 Yarder with a 70-ft. tower was analyzed for central landing locations, using PLANS. This yarder would be used on ridgetops and ridge noses with adequate landing spaces. This versatile slackline yarder can be rigged with either a 1 1/8-inch or 1inch skyline. The external yarding distances (EYD) would be 2000 feet and 2500 feet respectively. When analyzing PLANS, the 1-inch skyline option was selected. The carriage option was the T-Bird MSP (heavy) mechanical slackpulling carriage. The range for the landing size requirements is between 1/10 and 1/4 acres. In places where landing space is available, a log processor can be used and tree length logs can be yarded.

The site would include a Caterpillar 325 Log Loader. The 7-man crew includes yarder engineer, loader operator, hooktender, rigging slinger, landing chaser, and two chokermen. The owning and operating costs for the site are $3,528 per day.

The choice for the mobile yarder was a Thunderbird TSY6155 Swing Yarder. This is an inhaul interlock machine that operates with a running skyline. The EYD is 2000 feet, using ¾ inch main, haulback, and slackpulling lines. This swing yarder is capable of decking logs and with available space, it can operate on continuous landings with or without a loader. The landings can be on road grades of less then 11%. The carriage option selected was the T-Bird MSP (medium) mechanical slackpulling carriage.

The on-site equipment will be a Caterpillar 325 Log Loader. The 7-man crew includes yarder engineer, loader operator, hooktender, rigging slinger, landing chaser, and two chokermen. The owning and operating costs for the site are $3,366 per day.

The Koller 501 Thinning Yarder, with a 40-foot tower option, was selected for analyzing thinning operations. This yarder can be mounted either on a trailer or a truck. For our analysis, we selected the truck mount option. The external yarding distance with a ½ inch skyline is 1600 feet. This yarder can be used on central landings or continuous landings. The carriage option selected was the Eagle Eaglet radio controlled motorized slackpulling carriage.

The site includes a Caterpillar 322 Log Loader. The 5-man crew comprises of the yarder engineer, loader operator, hooktender, rigging slinger, and landing chaser. The owning and operating costs for the site are $2,581 per day.

Ground skidding will be used on slopes with less than 30 percent since soil stability and ground conditions within this range are considered acceptable. The track skidder operates effectively on slopes up to 30 percent whereas the skidders operate effectively on slopes up to 20 percent. In our two ground system examples, the combination of tire and track skidders are used because the rubber tire skidder is more efficient on the flat or gentler terrain, and the track skidder will be able to negotiate the steeper ground skidding areas. The track skidder will also be used in areas where a machine with less ground pressure is needed.

Another system using cut-to-length technology or a feller-buncher could be configured, but due to the broken terrain, there were insufficient flat or gentle sloped areas to warrant their usage.

This site includes a Cat 325 Log Loader, Cat 515 Rubber Tire Skidder with grapple, and a Cat D5H TSK Track skidder. The four-man crew includes a loader operator, two skidder operators, and a landing chaser. The owning and operating costs for this site are $3,138 per day.

This site includes a Cat 325 Log Loader, Cat 515 Rubber Tire Skidder with grapple, Cat D5H TSK Track skidder with grapple, and Cat 320L Stroke Delimber. The four-man crew includes a loader operator, two skidder operators, and a delimber operator. The owning and operating costs for this site are $3,313 per day.

In this site a Cat 325 Log Loader or similar track mounted loader (shovel) does the yarding and loading. On ground that is either level or has a constant slope, the shovel can efficiently yard by shuffling the logs to the road or landing. The shovel can effectively yard either tree length or log lengths up to 400 feet. In the Washougal Planning Area, several areas along roads have trees that can be directional felled, within reach of the shovel. The two-man crew includes a loader operator and a landing chaser. The owning and operating costs for this site are $2,168 per day

Helicopter logging was analyzed using the Helipace program. The K-Max Helicopter was selected and three of our harvest polygons were analyzed.

This site includes a Cat 325 Log Loader, and a Cat 980 wheel loader. The logging crew size ranges from 10-12 men. This generally includes two loader operators, two hookers, four choker setters, two landing chasers, and one or two choker bundlers. Also needed are two pilots, two copilots, and two mechanics. The felling crew may range from 5 to 10 cutters depending on the size of the timber and helicopter production. The owning and operating costs, including timber felling for this site are $16,750 per day.

The helicopter logging option clearly the most expensive logging option. The mechanical option also requires more then double the capital investment of other options excluding the helicopter. Both those options need sufficient timber for constant harvest levels to sustain them. The shovel and thinning sides have the lower investment costs and the shovel obviously has the lowest operating costs, but they both have somewhat limited applications. The owning and operating costs for the helicopter were determined using Helipace. The owning and operating costs for thew other systems were computed using The WFI model. Both models included associated site costs such as mobilizations, fire truck, maintenance truck, fuel truck, communication, supervision, and administration.

Preliminary production estimates were generated using a summary of proposed settings that were digitized into PLANS. The profiles were broken down into three payload categories and four tailhold heights for number of profiles and average length of profiles. For an example see Table 12.2. These inputs used in conjunction with maximum LYD, actual planning area acres, and volume per acre generated the estimates in Table 8.2.

Table 8.2 compares the yarding costs for different payloads and volumes per acre for the three different yarders. There is clearly a large difference in cost/MBF as payload changes. Payloads of at least 3100 lbs. are needed to keep the yarding costs down. When the MBF/acre is less then 25 MBF/acre attaining payloads of 2400 lbs. Or greater may be difficult.

Table 8.3 Lists the values for four different systems. The values are total acreage, number of settings, setting size, trees per acre, volume per acre, and total volume. The average trees size approximately 0.063 MBF. This means it will take about four trees or at least six logs to make up a turn weight of 3000 lbs. Given the small volumes per acre and density of trees expected turn weights of 3000 lbs. are reasonable.

Table 8.4 Represents the values for volume, AYD, and acres for SNAP Period 1; 1998 to 2003. From this table we can see that snap choose units with greater volume per acre. We can assume that units with volumes per acre less then 22 MBF/acre are close to the breakeven border line, and should be allowed to grow more and increase their volume.

Table 8.5 Represents the production ranges for the systems analyzed. The higher costs per MBF are associated with the lower production values. The wide ranges for the tower and mobile yarders are due mostly to the small-expected turn weights in the first five-year period. In the following periods production range closer to the high end in periods three through five (see Table 12.7) as the timber volume increases.

This table is similar to the SNAP yarding cost input screen and shows how the yarding costs are inputed into SNAP. The Max EYD column uses the maximum external yarding distance to determine eligible harvesting systems. The column 'Yarding $/MBF' is a base cost. Yard Coefficient ($/MBF/ft) is the coefficient, that is multiplied by the AYD. These two costs are added together to make up the Total Cost $/MBF. The column "Other $/MBF" is usually used for other costs, such as felling. Since the felling costs have been included in the base cost for our calculations, this column is left blank

For example, if an AYD for Tower yarding were 500 ft and the cost would be $100.50/MBF. Similarly, at an AYD of 1000 ft., the cost would be $122/MBF.

Road costs inputted into SNAP. See appendix 8 for detailed example.

Figure 8.1 Represents the increase cost per MBF as AYD increases and turns per day and production decrease. This graph was generated using production estimates from Skyap 97with parameters 37 MBF/acre, 7,200 lbs. Payload (0.60 MBF), and 1500 fpm outhaul line speed.

This graph shows the increase in the site cost, and decrease in production as average yarding distances increase. In this particular case comparing yarding 1200 ft. and 1800ft. EYD respectively, there is 76.4 MBF from 0 to 1200 ft. EYD, and 38.2 MBF from 1200 to 1800 ft. The yarding costs are $87/MBF and $193/MBF respectively.

Bibliography

Conway,Steve.1982 Logging Practices, Principles of Timber Harvesting Systems. San Francisco: Miller Freeman Publications, Inc.

U.S. Forest Service. 1997. Region 6 Logging Cost Guide. U.S. Forest Service

McGonagill. 1978. Logging Systems Guide. Alaska Region, Forest Service, U.S. Department of Agriculture.

Peters, Penn A. 1974. A New Approach to Yarding Cost Analysis. 1974 Skyline Logging Symposium.

Merry, Luke A.F. 1985. Skyline Anchors and Multiple Stump Anchors. College Of Forest Resources, University of Washington

Macleod, D.A. 1976. Analysis of Forces Required to Pull Out Stumps of Varying Age and Species. Forest Management institute, CFS, Ottawa, Canada.

Forest Engineering Inc. 1985. Setting Design For Cable Systems. Forest Engineering Inc.,Corvallis, Oregon.