Terrain is the leading factor in deciding which systems can be used throughout the Big Country planning area. The terrain in the planning area is mostly steep and has very little area that ground based equipment can be used on. We will not be discussing ground based systems in great detail.
The choice of what system to use is dictated by site conditions. On level ground with slopes 0-30 percent, ground based systems can be used when the soil conditions are suitable. If the soil is too sensitive or the slope is greater than 30 percent, cable systems are employed. When the terrain is severely broken or there is no way to get a road to the site to facilitate yarding, helicopters are used. Ground operations are generally least expensive followed by cable systems, with helicopter logging being the most expensive.
7.1.1 Ground Systems
The terrain in the planning area limits the use of ground equipment. All the ground units in the planning area were analyzed with two high-tracked Caterpillar D5’s and a loader. The places on the sale where ground systems could be employed could also be harvested with a fellerbuncher and forwarder or any number of felling and yarding systems but for our analysis manual felling and two crawler tractors were chosen.
7.1.2 Cable Systems
Cable systems are limited less by the steep topography and more by shape of the ground. Cable systems are best suited for areas where the slopes are between 30% and 100+%. The major limiting factor is shape. A ground profile can be classified as concave, planar, or convex. The ideal ground profile is highly concave. This allows the cable system the greatest deflection, and therefore the highest payloads. The most difficult profile is highly convex. This ground shape affords little or no deflection and therefore payloads tend to be uneconomical. In the planar case, deflection can usually be found, but most times this requires rigging a tailhold tree 30-50 feet high and/or through the use of intermediate supports.
For the Big Country project, both a Madill 071 and T-Bird 6150 yarder were used for analysis. Both are medium sized yarders that are appropriate for the timber size on the sale. Additionally, Madill yarders are commonly used on the Olympic Peninsula. Since the two yarders are similar in size and capabilities, we used the 6150 to calculate production rates and stump to truck costs due to the fact that large amounts of data on this yarder had previously been entered into the USFS Region 6 log cost program by Rick Toupin, USFS logging systems specialist.
7.1.3 Helicopter Systems
The major benefit of a helicopter system is that it doesn’t need road access into the unit. This can be a huge benefit in steep, remote areas where road building is too costly or physically infeasible. It is also favorable in highly sensitive areas, such as near wetlands, because the site disturbance minimal. The major detriment to helicopter logging is that it is expensive and highly sensitive to turnweights and flight distance. As a rule of thumb, if turn time is over three minutes or if turns/hour drops below twenty it is likely that helicopter yarding will not be cost effective. For this reason the maximum external flight distance is approximately one mile. When selecting a helicopter for yarding, possible turnweights should first be estimated from stand data. Then the helicopter that has a maximum payload nearest to the turnweight should be selected. The goal is to maximize the payload for each turn. Another limiting factor for helicopter logging is the availability of adequate landings. A good helicopter landing must be at least four acres in size. This is to accommodate both the landing/decking of logs as well as the refueling of the helicopter and loading of trucks. An alternative analysis for the use of helicopter logging on the Big Country Timber Sale can be found in section 7.8.
7.2.1 Cable Analysis
The DNR provided us with a 10-meter Digital Elevation Model (DEM). However, this DEM did not provide adequate resolution for the detail required in our design. We chose instead to use a 1”: 400’ paper contour map as a basis for our design. Using this contour map, we identified settings and created yarding corridor profiles to be analyzed on PLANS and LoggerPC.
PLANS is a computer program that analyzes multiple profiles for each setting. We used this program as a quick method of analyzing many settings. Because we did not have a detailed DEM, we were not able to use PLANS for large scale analyses of settings. Instead, we used LoggerPC, a computer program that analyzes independent profiles for yarding payloads and feasibility.
7.2.2 Cable Analysis Assumptions
The following assumptions were used in our cable analysis:
| -Madill 071 Tower: | 47’ |
| -Eagle Eaglet Carriage: | 1300 lbs |
| -Skyline: | 1” |
| -Choker length: | 15’ |
| -Turn size: | 3.5 logs |
| -Turn weight: | 1100-6100 lbs |
(Turn size and weights are defined by the RIU stand data of our silvicultural analysis. Rigging tree sizes and availability were determined by RIU stand data.)
7.2.3 LoggerPC analysis
We analyzed approximately 200 profiles for payload analysis and feasibility, as can be seen in figure 27. Of these 200 profiles we identified 8 that produced marginal results. We verified these 8 profiles in the field. Some areas do not have profiles. These areas are either suitable for ground based harvesting, or the corridors are not long enough to justify a detailed analysis. Figure 27 shows the profiles we analyzed in LoggerPC and in the field.
7.2.4 Choosing Payloads
Payloads were chosen based on stand data provided. Several assumptions need to be made when calculating payloads. First, how many logs will be yarded per turn? For our calculations we assumed 3.5 logs per turn for three chokers. Second, what size logs will be yarded? Will they be tree length, or a specified length? We calculated our payloads for 32’ logs. Third, what does the wood weigh? Based on scale weights from a stud mill on the peninsula the average board foot of wood weighs 10.9 pounds. Third, what is the average piece size for the logs being yarded? Our planning area was broken down into several different stands with varying average log sizes so payloads needed to be calculated for each RIU. Lastly, payloads will also differ depending on the level of cut. Regeneration harvests result in the highest payloads while light thins produce lower average log sizes and payloads. Based on all the information given above, payloads were calculated by the following formula:
3.5 logs/turn * 10.9 lbs/bdft * average # bdft/log = lbs/turn
7.2.5 Setting Layout
Now that payloads for the stands are calculated, a harvest plan needs to be designed so that these payloads can be feasibly and economically yarded. The first step is determining what logging equipment is available and appropriate for the job. If payloads are large, small equipment will not get the job done. If the payloads are small, large equipment would not be cost effective.
Once equipment is selected, specifications such as line sizes and lengths need to be determined. Tensions, and hence payload capabilities can be figured for varying line sizes. Skyline lengths and/or haulback lengths will determine the external yarding distance the yarder is capable of. A lateral step that should be taken before the setting layout progresses is determining the most efficient yarding distance. The two main costs to timber harvest are road building costs and yarding costs. As road density (and cost) increases, yarding distance (and cost) decreases. The ideal yarding distance is where the two curves intersect on a $/mbf vs. yarding distance graph. For this we used the Simyard computer program. Information about the equipment to be used and expected harvest volumes are entered and the graph is plotted. For our particular unit the most economical yarding distance was around 1,100-1,300 feet.
After the machine specifications are reviewed and yarding distances are figured, the settings are ready to be laid out. For this step, the topographic map with contour lines and the unit boundaries are needed. The ground needs to first be classified into classes of steepness. For our analysis we reclassified the ground into areas of slope 0-30%, 30-55%, and > 55%. There are two reasons for this: First, ground based harvest is possible up to roughly 30% slope and those areas should be taken advantage of since the cost is significantly less than cable yarding. Second, road building costs into areas of slope > 55% increase significantly. Once the areas that can be skidded are marked out the remaining area needs to be cable yarded. Short distances and uphill yarding are greatly preferred by loggers so emphasis should be made to design around those criteria where possible. The tower must be set up on a road or landing so when choosing landing locations road access must be considered. Landings are best located at the breaks of ridges or flat stretches of road. All areas within the unit must be able to be accessed from somewhere so spacing between profiles should not exceed the lateral yarding capability of the system being used.
7.2.6 Analysis
Once the landing locations were chosen on the map they were digitized into PLANS (Preliminary Logging Analysis) and the profiles roughly analyzed and adjusted for length. After the preliminary analysis, all the profiles were digitized into LoggerPC. The profiles were then checked against the anticipated payloads from the stand data. The procedure for analyzing the profiles in LoggerPC is detailed in Appendix 10.3.
The DEM accuracy needed to be verified to ensure that the work being performed
in the office was a viable alternative to walking every profile. Several
of the profiles that showed marginal payloads were verified in the field.
The field profiles were then compared to the DEM profiles. The DEM seemed
to smooth out the more critical points of the profile, making them less noticeable.
7.3.1 Marginal Profiles
The 8 profiles highlighted in yellow in Figure 27 in section 7.2.3 are profiles that produced a marginally acceptable payload. We verified these profiles in the field by performing a profile traverse. These profiles are described below in Table 15.
Table 15. Payloads of marginal profiles
|
Profile |
Payload (lbs) |
Intermediate Supports |
|
F1W-3 |
5000 |
0 |
|
F4E-3 |
2900 |
1 |
|
F2E-2 |
5858 |
2 |
|
F8W-3 |
5547 |
0 |
|
F2W4 |
5325 |
2 |
|
W3A |
5410 |
1 |
7.3.2 Profile Comparison
We performed a comparison of the map-generated profiles against the field-generated profiles. There is a discrepancy in their results. However, we feel that the map is an adequate source for our analysis because the 8 marginal profiles that we analyzed in the field all proved to be feasible. Most comparisons showed the map-generated profile to be the more conservative of the two, as seen in Figure 28.
The desired payload was set at 5,200 lbs to ensure that any plausible payload was achievable for the chosen system. The silvicultural data indicated that this was the maximum that could be expected for any type of harvest, thinning or regeneration, in the planning area. [j1]
Two helicopter settings were created by dividing the planning area approximately in half, creating west and east settings. We found that helicopter logging was only cost effective if it did not require building new roads. That required that there be suitable landings on the existing roads. From the contour map and existing road coverage it was determined that the best locations for helicopter landings were on the P-1000 for the west setting and on a spur in the Cabin Fever Sale for the east setting. The program we used for analyzing helicopter logging, Helipace, calculated flight distance from the landing to the centroid of the harvest area. By estimating the centroids on the map and measuring the distance to the selected landing location, we found that both settings had flight distances around one mile. This distance is usually considered marginal at best.
In our searching we found a new product that is an alternative to the standard yarding cable. PowerFlex cable is made by Macwhyte and can be used to increase safe working loads by 50%. The price per foot is $2.60 versus $2.37 for standard cable. We ran a profile to compare PowerFlex cable to a standard cable. A 1” EIPS cable offers a safe working load of 34,000 lbs. For the profile we ran, this produces a 2,700 lbs payload. A 1” PowerFlex cable offers a safe working load of 49,000 lbs. For the same profile we were able to get a payload of 5,300 lbs (See Table 16). PowerFlex cable is slightly more expensive, but the increased payloads may justify the cost. Please see Washington Administrative Code 296-54-553 concerning regulations for towers on cable size and capacity. It is up to the DNR and the contractor to determine if this is a safe and legal option for a yarding operation. More information about this product can be found at www.wrca.com.
|
43. Line size |
44. 9/16” |
45. 7/8” |
46. 1” |
47. 1 1/8” |
48. 1 3/8” |
|
49. Standard Safe Working Load (lbs) |
50. 33,600 |
51. 79,600 |
52. 103,400 |
53. 130,000 |
54. 192,000 |
|
55. PowerFlex Safe Working Load (lbs) |
56. 48,000 |
57. 115,000 |
58. 151,000 |
59. 186,000 |
60. 263,000 |
7.6.1 Costing Models Used
Several costing models were used for the analysis of logging equipment cost and production. First, SL_Pro, designed by Weikko Jaross (DNR/UW liason), was used to find O & O costs (Owning and Operating Costs) for everything from felling to loading. When possible, several pieces of equipment of the same type and size but different manufacturer were calculated and averaged to assure a better cost estimate. Skid_PC, designed by John Sessions (OSU), was used to find both O & O costs as well as production estimates for ground based equipment. Likewise, Helipace, designed by Rick Toupin (USFS Region 6 loggings systems specialist), was used to calculate O & O and production numbers for helicopter yarding.
The next step was to calculate production rates for the various pieces of equipment. As was already stated, ground production rates came from Skid_PC, cable production came from Rick Toupin’s Region 6 log cost program, and helicopter production came from Helipace. Production for felling, bucking, processing, and loading were derived from equations found in the FERIC report “Harvesting Coastal Second-Growth Forests: Summary of Harvesting System Performance” in the March 1998 edition.
Lastly, the $/MBF calculations were found by dividing the O & O cost by the production rates (MBF/hr) to arrive at $/MBF values. Simyard, designed by Weikko Jaross, was also useful for estimating cable yarding costs as a function of yarding distance. The important inputs for the program were vol/acre, turn volume, and operators cost for the entire logging side.
The main assumptions that were made and used throughout calculations were fuel cost of $1.35/gallon and 220 work days/year.
7.6.2 Purpose
By combining the equipment costing information with the production information we can obtain the contractor’s cost per unit volume and/or cost per day. This is particularly important for determining the minimum bid price for timber sales and for the bidder to know if the sale would be profitable for them. By comparing logging cost $/MBF versus mill price $/MBF a contractor can make a reasonable bid on the sale. If the low bid is significantly lower than expected, it may be cause for further review.
7.6.3 Method
To better estimate costs, we included all equipment, owning and operating, and overhead cost associated with a sale. To do this we determined all the equipment that is required for a typical timber sale. The equipment was combined in several different systems in order to capture any given situation that presented itself. Each part of the logging process (felling – loading) was calculated independently for all possible types. For example, felling was broken down into manual and mechanized. Ground was broken down into cat, skidder, and shovel. Cat and skidder were then further broken down into line and grapple and for bunched and unbunched logs. The Vertol helicopter that was used for analysis was recommended by Rick Toupin based on site conditions and stand data we provided to him.
Actual $/MBF costs are the result of the total O & O for each piece of equipment per day divided by the volume of timber processed in one day. The $/MBF cost to run the loader or processor for example is highly variable and dependent on the wood available to it. In conclusion, probably the best way to estimate $/MBF for equipment is to estimate the number of loads that can be produced in one day (assume 4 MBF/load) and divide the O & O cost by the board foot volume. Based on the stand data for the Big Country area, type of yarding system, and the type of harvest (uniform, light, or heavy thin, or regeneration harvest), the number of loads/day ranged from 4 to 20. A production costing summary is provided in Section 7.7
7.7.1 Felling
Felling can be done manually or mechanically where topography allows. Manual felling and feller buncher costs/hr were generated from SL_Pro (computer program). Production estimations were generated from equations found in the FERIC report “Harvesting Coastal Second-Growth Forests: Summary of Harvesting System Performance” in the March 1998 edition. From the $/hr and the mbf/hr calculated a $/mbf value was obtained. Manual fell & buck as well as just felling costs were generated for each prescription.
Assumptions –
n The average volume/tree across all the RIU’s in the planning area was used in the volume equations (for each prescription)
n Cost/hr for equipment used was the average of several comparable pieces of equipment found in SL_Pro
n A medium sized feller buncher was used at 75% Utilization
The results are found below in Table 17.
|
Manual Felling |
Prescription |
$/hr to operate |
MBF/Hr |
MBF/Hr |
$/MBF |
$/MBF |
|
Fell & Buck |
Fell |
Fell & Buck |
Fell |
|||
|
|
Uniform |
41.26 |
1.56 |
3.13 |
26.38 |
13.16 |
|
|
Light |
41.26 |
1.83 |
3.68 |
22.53 |
11.20 |
|
|
Heavy |
41.26 |
2.11 |
4.27 |
19.53 |
9.67 |
|
|
Clearcut |
41.26 |
2.69 |
5.48 |
15.33 |
7.53 |
|
Feller Buncher |
Prescription |
$/hr to operate |
Fell & Bunch |
|
$/MBF |
|
|
|
Uniform |
105 |
58.76 |
|
25.02 |
|
|
|
Light |
105 |
62.85 |
|
23.39 |
|
|
|
Heavy |
105 |
67.57 |
|
21.76 |
|
|
|
Clearcut |
105 |
78.99 |
|
18.61 |
|
7.7.2 Yarding
7.7.2.1 Cable Yarding
Cable Yarding has the most factors influencing cost, so data was taken from several sources to verify accuracy of results. $/hr costs were compiled using SL_Pro and USFS Region 6 log cost program. Several similar sized yarders were compared and factors such as turn size, cable size, ayd, etc. were kept constant. Production estimates were arrived at by using the Simyard program and working backward given $/hr and $/mbf. The Region 6 cost program was also used as a reality check for production. The FERIC report contained several equations for computing production but were all based on clearcut conditions and larger log sizes (190 bdft/log). As a result production estimates tended to be high and therefore $/mbf values were low. These data were not used in our calculations.
Assumptions:
n An AYD of 500’ and 3.5 logs/turn
n $/hr for tower includes the machine, operator, and crew of four.
n Turn weights/volumes were based on stand data provided and 10.9 lbs/bdft, which came from scaling information at a local mill.
n Hook/unhook time for chokers was calculated from the FERIC equations and assumed not to vary much with turn size but rather more with # of chokers.
n Line speeds were calculated from the equations in the publication by Charles Mann.
n Truck loads were assumed at 4 mbf/load
The results are found in Table 18.
Table 18. Cable yarding costs were determined by compiling data from several sources.
|
Prescription |
$/Hr to Operate |
82. MBF/Hr |
Loads/Day |
$/MBF |
|
Uniform |
225 |
2.16 |
4.59 |
104.17 |
|
Light |
225 |
2.43 |
5.16 |
92.59 |
|
Heavy |
225 |
2.88 |
6.12 |
78.13 |
|
Clearcut |
225 |
3.74 |
7.95 |
60.16 |
* Note: Region 6 log cost program produced a value of $ 436/hr, which includes cable yarding, mechanized processing, a landing cat, and a shovel/loader and a total crew of 8 personnel. Total move in/move out cost equals $6,900.
7.7.2.2 Shovel Yarding
Not much data was available on shovel forwarding. FERIC did not provide any equations but rather a range of potential productions based on external distance and piece size. These were not very applicable to our situation since the graphic extended only to an external distance of ~ 150’ and piece size was much larger than our stand data supported. Phone calls were made to independent contractors and a consistent answer of 20 loads/day for average sized timber on 10% ground and clearcut harvest was arrived at. Since shovel logging is difficult in thinnings due to the inability to swing through residual trees we will provide only a cost for clearcut conditions and an external yarding distance no more than 400’. $/hr cost was the average of several mid-sized (200 series) shovels from SL_Pro.
Assumptions:
n 4 mbf/truckload
n 8.5 hrs/day
Results:
Based on the limited information we were able to obtain a ballpark estimate of $11.70/mbf.
7.7.2.3 Grapple Skidding
Grapple skidding costs were calculated using Skid_PC (computer program). The machine used for cost analysis was a Clark 667. Values were calculated for 3 log turns and 4 log turns because increased turn volumes would result from mechanically felled and pre-bunched wood. Cost per hour to run the machine was generated using SL_Pro.
Assumptions:
n 32’ logs were used for the thinning volumes and tree length logs were used in clearcut situations
n 10% slope and 400’ external distance were assumed in calculations
n Cone index was set at 75 to reflect wet soil conditions most of the year
The results are shown in Table 19, below:
Table 19. Grapple skidding costs were determined using Skid_PC and SL_Pro.
|
Prescription |
$/MBF (3 log turns) |
$/MBF (4 log turns) |
|
Uniform Thin |
19.38 |
14.63 |
|
Light Thin |
17.58 |
13.34 |
|
Heavy Thin |
15.23 |
11.52 |
|
Clearcut |
8.46 |
6.48 |
7.7.2.4 Line Skidding
A Cat D6 was used for this Skid_PC analysis. This machine is too large for a small wood thinning but adequate for clearcut harvest. The cost was very similar for a Cat D5H, which would be better suited for thinning conditions and is capable of operating on slightly steeper slopes. So the analysis is appropriate for both. Cost per hour was generated from SL_Pro. The cost for line skidding is higher than grapple skidding out to a distance of approximately 550 feet, after which line skidding becomes cheaper due to the ability to yard larger payloads/turn. Mechanical felling and bunching allows for more pieces per turn and therefore greater turn volume. That is the reasoning for four log turns and 5 logs turns.
Assumptions:
n 32’ logs were used for the thinning volumes and tree length logs were used in clearcut situations
n 10% slope and 400’ external distance were assumed in calculations
n Cone index was set at 75 to reflect wet soil conditions most of the year
The results can be found below in Table 20:
Table 20. Line skidding costs were generated with Skid_PC and SL_Pro.
|
Prescription |
$/MBF (4 log turns) |
$/MBF (5 log turns) |
|
Uniform Thin |
45.96 |
36.91 |
|
Light Thin |
41.88 |
33.65 |
|
Heavy Thin |
36.17 |
29.24 |
|
Clearcut |
20.15 |
16.45 |
7.7.2.5 Helicopter Yarding
Difficult yarding conditions can sometimes be done cost effectively with the use of helicopter yarding. Part of the Big Country timber sale contains difficult yarding ground and should be considered for helicopter yarding. Helicopter yarding is highly sensitive to variations in turn volume, flight distance, etc. We contacted Rick Toupin, USFS Region 6 logging systems specialist, to clarify a few things and provide us with accurate estimates for our analysis. We used Helipace (computer program), designed by Toupin, to come up with our cost for this logging system. The analysis is based on a Vertol helicopter out of central Oregon.
Assumptions:
n If effective minutes/turn exceeds 3, yarding will likely not be profitable
n If effective turns/hour fall below 20, yarding will likely not be profitable.
n The costs calculated are stump to mill costs and include everything from felling through trucking and include no road building costs.
Note: Trucking was estimated based on mileage to Portac Mill in Beaver.
Results:
The cost to operate the helicopter including loading, processing, and ground crew was figured to be $2,323/hr.
7.7.3 Processing
7.7.3.1 Manual Processing
Depending on the degree of processing done when the tree is felled some processing will need to be done on the landing. This can either be done manually or mechanically. Manual processing requires the aid of the loader to move logs around for the chaser (roughly 30% of the loader’s time). We used the equations in the FERIC report to calculate production rates and costs for one chaser and two. The cost/hour for labor came from the Region 6 program.
The results can be found below in Table 21:
|
|
$/MBF (one bucker) |
$/MBF (two buckers) |
|
Uniform |
11.41 |
18.24 |
|
Light |
10.79 |
16.50 |
|
Heavy |
9.87 |
14.19 |
|
Clearcut |
8.18 |
10.59 |
|
|
|
|
|
Uniform (tree length) |
10.71 |
16.28 |
|
Light (tree length) |
9.40 |
13.11 |
|
Heavy (tree length) |
8.28 |
10.78 |
|
Clearcut (tree length) |
6.43 |
7.56 |
7.7.3.2 Mechanical Processing
There are several types of processors on the market today but for our purposes all types were grouped as one. Operating costs were averaged for stroke delimbers and excavators with processing heads such as a Keto or Waratah. $/hr was calculated using SL_Pro. The production equation we used came from FERIC and was modeled after a Denis stroke delimber. Processors are used primarily after tree length yarding but log length data was provided as well. FERIC’s data suggested that a processor working independently (without aid of loader to move processed logs) can work most cost effectively. However, if the loader is used to sort or otherwise move processed logs there is little difference in cost between manual and mechanical processing.
Assumptions:
n 80% utilization assumed
n Equation was modeled around larger wood, we are assuming the equation holds true for smaller stem sizes.
The results are shown in Table 22, below:
|
|
MBF/Hr (log length) |
MBF/Hr (tree length) |
$/MBF (log length) |
$/MBF (tree length) |
|
Uniform |
3.43 |
4.96 |
27.73 |
19.17 |
|
Light |
4.78 |
7.90 |
19.90 |
12.04 |
|
Heavy |
6.83 |
10.56 |
13.93 |
9.00 |
|
Clearcut |
10.80 |
15.43 |
8.80 |
6.16 |
7.7.4 Loading
Loading cost is dependent on wood and trucks available. Also the loader’s time is divided between multiple tasks so only a fraction of every hour is spent loading. FERIC estimates that if shift level production was from 48-95 mbf/shift and performed no other task, the loading cost would range from $13.10 – $26.15. The cost/hour to run the machine was found using SL_Pro but was also supported by costs found in the FERIC report.
7.7.5 Owning & Operating Costs
Table 23, below, shows a list of equipment that was used to obtain an accurate assessment for cost analysis. The assumptions used in creating these values are listed below the table.
Table 23. A list of equipment that was used to obtain an accurate assessment for cost analysis.
|
Equipment |
Type |
$/hr |
Risk&Profit |
Total Cost/hr |
||
|
Tbird 6150 |
Swing Yarder |
191.15 |
28.67 |
219.82 |
||
|
Diamond 210 |
Swing Yarder |
191.40 |
28.71 |
220.11 |
||
|
Westcoast |
Swing Yarder |
209.48 |
31.42 |
240.90 |
||
|
Manual Felling |
Chainsaw |
35.88 |
5.38 |
41.26 |
||
|
Timbco 425 |
Feller Buncher |
79.57 |
11.94 |
91.51 |
||
|
LinkBelt 2800 |
Feller Buncher |
65.98 |
9.90 |
75.88 |
||
|
Cat D5H |
Cat |
44.18 |
6.63 |
50.81 |
||
|
JD 548G |
Skidder |
50.81 |
7.62 |
58.43 |
||
|
Cat 527 |
Skidder |
81.42 |
12.21 |
93.63 |
||
|
LinkBelt 3400 |
Shovel |
81.26 |
12.19 |
93.45 |
||
|
Case 9030 |
Shovel |
106.57 |
15.99 |
122.56 |
||
|
Kobelco 200 |
Shovel |
92.15 |
13.82 |
105.97 |
||
|
Kobelco 150 |
Processor |
68.98 |
10.35 |
79.33 |
||
|
Timberjack 1270 |
Processor |
96.57 |
14.49 |
111.06 |
||
|
Assumptions/Notes: |
|
|
||||
|
|
|
|
||||
|
All $/hr numbers came from SL_Pro |
|
|||||
|
Fuel Cost assumed at $1.35/gal |
|
|||||
|
220 operating days/year |
|
|
||||
|
8.5 hrs/day |
|
|
||||
|
6hrs/day for cutters |
|
|
||||
|
Risk/Profit = 15% of hourly cost |
|
|||||
|
Manual Felling includes only one cutter |
|
|||||
|
Labor included: |
|
|
|
Tower = operator + 4 |
|
Shovel = operator + 1 |
|
Processor = operator |
|
Cat/Skidder = operator |
|
Feller Buncher = operator |
7.7.6 Conclusion
The equipment chosen is reflective of the size of timber found on the Big Country planning area. By listing equipment costs independently, a system can be custom built around the equipment available in the area and the $/MBF cost for each piece can be easily calculated provided a production estimate is known.
The Big Country planning area provided many challenges both in road design and harvest systems design. At this point there is still no final word on how the area will be accessed. To provide an alternative to road building an analysis was performed comparing helicopter logging versus conventional cable yarding.
Cable yarding requires approximately 700 stations of road to be built or reconstructed at a cost of nearly $2 million. Based on existing roads and the roads we traversed in the field the average cable yarding distace was calculated to be roughly 500 feet. During the preliminary planning for this project all profiles were analyzed in Logger_PC and all were found to be feasible based on the stand data provided. Payloads varied based on the stand and the type of harvest employed but values ranged from 2,600 – 4,400 lbs for log length turns. Stump to truck costs for the cable system were calculated using a Thunderbird 6150 yarder, a 200 series log shovel, and a Kobelco processor. Logging costs ranged from $109/MBF for regeneration cut to $249/MBF for uniform thin. Helicopter costs were more difficult to quantify due to the uncertainty of flight distance.
Certain areas within the planning area incurred exorbitant logging costs when analyzed with a cable system. Generally, this was a result of long yarding distance and a light payload. One benefit of helicopter logging is the larger turn size. When talking to Rick Toupin about reasonable parameters for payloads he suggested five piece turns. We also had the benefit of watching a helicopter show in progress near the Synder work center. Typical turns were four or five pieces. Unlike cable yarding where deflection is an issue, helicopter yarding provides complete deflection. Therefore tree length logs can be yarded without damaging residual trees or creating hang-ups. The Vertol helicopter used in the analysis has a payload capacity of 8,000 lbs. This is more than adequate for the payload ranges we can expect. At the low end uniform thin payloads average 3,200 lbs and at the high end regeneration cuts average 6,900 lbs. The unknown variable for helicopter logging in this situation is flight distance. There are only a handful of possible landing locations on existing roads near the planning area. From these possible landings to the centroid of the sale area flight distance exceeds one mile in most cases and is only slightly under in the remaining cases.Using Helipace, the breakeven flight distance for logging cost between helicopter and cable yarding was found. The $/MBF logging cost for cable yarding was entered into Helipace and held constant. This allowed us to find the flight distance where this breakeven point occurred. Beyond this flight distance cable yarding became the more cost effective alternative. A third alternative is to build the roads and still helicopter yard. This would decrease flight distance and therefore increase productivity. However, it would require adding the road building cost to the system. The breakeven point was found in the same way only with drastically different results. It was found that cable was the cheaper alternative for all prescriptions and flight distances except a light thin at less than 400 feet flight distance. This is still not feasible due to the vast road network that would be required. A summary of logging costs and breakeven flight distances can be found in the following table.
|
|
Cable Logging Cost ($/MBF) |
Breakeven Helicopter Flight Distance (ft) |
|
Uniform Thin |
249 |
1,200 |
|
Light Thin |
235 |
2,600 |
|
Heavy Thin |
162 |
2,200 |
|
Regeneration |
109 |
3,300 |
7.8.1 Alternative Analysis Conclusions
From the location of existing landings it is not a viable option to helicopter yard the Big Country timber sale in its entirety. No analysis was done on each individual setting. It may be cost effective to use helicopters on certain settings depending on the prescription applied and the flight distance. Additionally it remains to be seen which access alternative will be used. This may change the economic viability of helicopter yarding somewhat.