United States 

Department of 

Agriculture - Technoeconomic Analysis of 

Forest Service Conventional Logging Systems 

Northeastern Forest 

Experiment Station Operating from Stump to Landing 

Research Paper 

NE-577 

1986 Raymond L. Sarles 

@ William G. Luppold 
I The Authors , Raymond L. Sarles is a research forest products technologist and William G. Luppold is an economist at the Northeastern Forest Experiment 

Station's Forestry Sciences Laboratory, Princeton, West Virginia. 

1 Manuscript received for publication 10 July 1985 

Abstract 

A technoeconomic analysis of timber harvesting systems was conducted to obtain key information for estimating longrun supply trends of 

roundwood materials from eastern woodlands. Productivity and cost factors 

for six stump-to-landing systems were developed from operational data for 

47 harvesting operations. Technical factors and the effects of financial considerations were also assessed. Combined with the productivity and cost 

factors, they provided better perception of the forces impacting longrun 

roundwood supplies and logging contractors' business options. 
Introduction 

Harvesting is one of the most expensive activities 

in the production of wood products, and harvesting 

costs directly influence the demand for stumpage and 

the supply of roundwood material. Therefore, one key 

piece of information needed to predict the longrun 

supply of roundwood materials from eastern woodlands is an analysis of the different systems that are or 

may be used to harvest timber. In this paper, we have 

analyzed stump-to-landing functions of six different 

logging systems employed in eastern forests. Our 

intent is to obtain a broad perspective of productivity 

and cost factors for them and to combine this information with technical, financial, and other considerations 

important in the selection of logging equipment and 

systems. 

This paper is presented in four sections. The first 

section presents technical and economic information 

developed from operational data from 47 harvesting 

studies. The second section presents technical factors 

that influence the use of a particular harvesting system 

on a particular site. Section 3 of this paper introduces 

the effect of the real-world considerations that loggers 

must face and their potential effect on selection of harvesting equipment and systems. The concluding section summarizes the materials presented in the previous sections and makes suggestions for future 

research. 

Comparative Analysis of Conventional 

Logging Systems 

Six conventional logging systems-horse, minitractor, crawler tractor, cable skidder, grapple skidder, 

and cable yarder-are compared in this section. The 

data for this analysis came from 25 published and 

unpublished reports. Altogether, the reports yielded 

information for 47 logging operations including 6 

horse, 5 mini-tractor, 8 small crawler tractor, 10 cableskidder, 9 grapple-skidder, and 9 small cable-yarder 

systems. For each logging operation; information was 

extracted on location, terrain, type of cut, species, 

mean stand diameter, roundwood products cut, yarding 

distance, load size per turn, capital cost of equipment, 

crew size, system cost per day, output per day and per 

man-day, and cost per unit of output (Appendix, Tables 

1 to 6). 

Volume of wood harvested was calculated in cords 

of wood plus bark. If outputs were recorded in other 

units, appropriate factors were used to convert them to 

cords. Cost per unit of output for each logging system 

was developed by summing daily labor and equipment 

costs and dividing this sum by daily output. For comparison purposes, all wages were fixed at $6/hour plus 

31 percent for employer-paid taxes and insurance 

(= $7.86), and all capital equipment costs were standardized to 1983 dollars using Producer Price Indexes 

for construction equipment. Machine rates for new 

equipment were based on ownership and operating 
costs per hour as determined by Cubbage (1980), or 

from data given in the cited reference. Machine utilization factors were based on data in the abstracted 

papers or from Miyata (1980). 

The data base includes terrain that ranges from 

flat to mountainous and many species, including hardwoods and softwoods. Conditions differ widely among 

the studies analyzed, but each operation was a legitimate harvest of trees found in forest stands. In that 

sense, the studies are representative of a population of 

forest harvesting operations, and the analyses reported 

here are based on this underlying assumption. Reported inputs and outputs for like harvesting systems were 

collated and analyzed, means and ranges of data for 

the six logging systems were compared, and relative 

inputs, outputs, and costs were assessed. 

Description of Logging Operations 

Six horse-logging operations, including both single 

and team hitches of draft horses, were analyzed. All 

operations were in mountainous terrain, and except for 

one in New Zealand, all were in the United States. 

Most were harvests of tree-length hardwoods from a 

variety of cuttings: thinnings, selection, and clearcuts. 

The usual crew size was two men-a faller and a teamster. On steep slopes in Montana, the crew used two 

horses, resting one while the other worked. 

Five mini-tractors, ranging in size from 12 to 48 

horsepower, extracted tree-length poles from thinnings 

in the Northeastern States. In all cases, the crew was 

two men-a faller and a tractor operator. 

Small crawler tractors of 42 to 78 hp operated on 

mountainous logging shows in the central Appalachians, British Columbia, and Washington state, where 

they thinned and clearcut stands of hardwoods and 

softwoods. Logging crews consisted of two men-a 

faller and a tractor operator. 

Rubber-tired cable skidders operated on 10 logging shows in West Virginia, Montana, and Mississippi 

on hilly to mountainous terrain. The skidders were 

equipped with winches for logging tree-length hardwoods and softwoods. Their engines ranged from 60 to 

125 hp; however, most were 90-hp machines. Harvests 

were thinnings, diameter-limit selection, and clearcuts. 

Crew size ranged from two to three men-a faller, a 

chokersetter, and a skidder operator. 

Rubber-tired grapple skidders working in conjunction with mechanical fallers of various makes,were 

used on nine whole-tree chipping operations In New 

England and the Lake States. The terrain was flat to 

moderately steep (slopes seldom over 15 percent). 

These skidders ranged from 90 to 152 hp. Harvests 

were mostly thinnings, extracting whole trees in hardwood and pine stands. Crew size varied from two to 

four men-one man operating the mechanical falleri 

and up to three men operating grapple skidders. 

Small cable-yarding systems were operated on 

nine logging shows in the Appalachians and the Northwest. The equipment included two jammers and four 

skyline yarders. Five operations were thinning jobs and 

the others were clearcuts and residue relogging. Both 

log-length and tree-length removals were made from 

stands of hardwoods and Douglas-fir. Crew sizes 

ranged from three to seven men, including fallers, yarder operators, chokersetters, chasers, and tractor operators on three jobs where swing operations were 

necessary. 

Production and Costs for Logging System 

Operations 

Analyses of production and costs were limited to 

the two basic, yet complex, logging functions-felling 

and extraction. (Log loading and transport functions 

were not included in our analysis.) The analyses were 

structured so that inputs of labor and machines were 

restricted to the number of each necessary for a producing unit within a given system. For example, one 

faller and one chain saw plus one crawler tractor and 

operator were considered one producing unit in the 

crawler-tractor system. Production data were based on 

the unit's output. Cost data were based on the sum of 

wages and fringe benefit costs for workers and the 

machine rates for equipment. Auxiliary equipment such 

as crew trucks, service trucks, bulldozers, welders, 

spare parts, etc., were not included in determining 

investment or production costs; nor were costs of 

stumpage, roadbuilding, landing construction, supervision, or overhead included in any of our cost 

calculations. 

Production and cost data were developed by the 

method described above for each logging operation 

within each of the six systems analyzed (Appendix, 

Tables 1 to 6). Within each system, production and 

cost data from the individual operations were summed, 

and means and ranges were calculated. Means and 

ranges of production and cost data are presented in 

tabulations and bar charts in the following pages of 

this section. 

' Mechanical fallers included both tree-to-tree (TT) and 

limited-area (LA) types. TT fallers and faller-bunchers must move from tree to tree; LA faller-bunchers have the felling 

mechanism mounted on a boom that can swing to reach 

several trees from one position of the carrier. 
Average capital investment ranged from a low of $2,318 for horse logging to $256,000 for grapple skidders coupled with mechanical fallers (Fig. 

1). Grouped by average dollar investment, the six logging systems rank 

roughly as shown in the following tabulation: 

Capital Investment Categories 

(thousands) 

<$4 $10-39 $40-69 $70- 139 >$264 

horse mini-tractor crawler cable yarder- mechanical-faller1 

cable skidder plus-swing grapple-skidder 

cable yarder operation 

HORSE MlNlTRAC CRAWLER CABLE GRAPPLE YARDER YARDER I SKlDDER SKIDDER W/sWrNG 

, MINIMUM EBZB3 MEAN 

MAXIMUM 

Figure 1.-Capital investment for equipment 
Evaluation of dollars spent for labor per hour compared to the hourly 

cost to own and operate equipment shows that the horse, small cable 

yarder, and mini-tractor systems are the most labor intensive (Fig. 2). 

Mechanical-fallerlgrapple-skidder systems, on the other hand, while requiring the largest capital investment, are the least labor intensive. This system 

has the highest productivity, with output averaging about 28 cords per manday (Fig. 3). Systems with low productivity-horse, mini-tractor, and small 

cable yarder-average 5 cords or less per man-day. And, with the exception 

of the small cable yarder, these systems rank in the lowest capital investment classes. 

0 L..-... 

HORSE MlNlTRAC CRAWLER CABLE: GRAPPLE YARDER YARDER 

SKIDDER SKIDDER W/SWING 

MINIMUM EBZZZi MEAN 

MAXIMUM 

Figure 2.-Ratio of hourly labor costs to hourly equipment costs 
20 

10 

0 

HORSE MINITRAC CRAWLER CABLE 

SKIDOER 

MINIMUM 

MAXIMUM 

Figure 3.-Production rate per man-day 

GRAPPLE YARDER 

SKIDDER 

MEAN 

YARDER 

w/mo 
The daily production rate (Fig. 4) follows much the same pattern as 

production per man-day. The mechanical-fallerlgrapple-skidder system produces, on the average, more than three times as much wood as the next 

most productive system. Average production per day is: 

Production Per 8- Hour Day 

<lo cords 10- 19 cords 20-29 cords >70 cords 

horse cable yarder crawler mechanical-faller1 

mini-tractor cable yarder-plus- cable skidder , grapple-skidder 

swing operation 

HORSE MlNlTRAC CRAWLER CABLE GRAPPLE YARDER YARDER 

SKlDDER SKlDDER W/smNo 

MINIMUM MEAN 

MAXIMUM 

Figure 4.-Production rate per day 
The mechanical-fallerlgrappls-skidder system is, on the average, the 

most expensive to own and operate, at close to $900 per day, while horse 

logging averages less than $200 (Fig. 5). The range of average daily costs 

among the six systems is: 

Logging System Owning-and-Operating Cost Per Day 

<$200 $200-299 $300-399 $600-899 

horse mini-tractor cable skidder mechanical-faller1 

crawler cable yarder grapple-skidder 

cable yarder-plusswing operation 

HORSE MlNlTRAC CRAWLER CABLE GRAPPLE YARDER YARDER 

SIUDDER SKlDDER W/sWnNG 

MlNlMUM MEAN 1 

MAXlMUM 

Figure 5.-Logging system cost per day 
For each system, manpower and equipment are buncher unit can keep two to three grapple skidders 

functions of the balance between the productivities of supplied with whole trees. Hence, instead of two men 

felling and skidding operations. With chain-saw felling, per producing unit, three to four are required. Nonethethe usual balance appears to be one faller per produc- less, productivity per man-day is highest for 

ing unit (but this can vary significantly with tree size mechanical-fallerlgrapple-skidder systems even though 

and skid distance). Productivity of mechanical fallers is larger crews are necessary to man the greater number 

two to three times that of chain-saw felling; one faller- of machines. 

Cable yarding crews are also somewhat larger than skidding crews 

because of the addition of a chokersetter and a chaser to the usual crew of 

faller and equipment operator. If a swing operation supplements the cable 

yarder, a skidder and operator must be added to the crew. In summary, typical crew sizes for felling and yarding operations fall into three categories: 

Typical Crew Size 

2 to 3 persons 2 to 4 persons 3 to 7 persons 

horse mechanical-faller1 cable yarder 

mini-tractor grapple-skidder cable yarder-pluscrawler swing operation 

cable skidder 

Daily production in cords and total daily costs of labor and equipment 

were used to determine cost per cord. Average cost per cord among the six 

logging systems was lowest ($13.03) for the mechanical-fallerlgrappleskidder system. Highest average costs were $30.98 and $41.69 per cord for 

the mini-tractor system and the small cable yarder-plus-swing operation 

(Fig. 6). Average costs per cord for the other systems fell in between these 

extremes: 

Logging System Cost Per Cord 

<$I5 $15-19 $20-29 >$29 

mechanical-faller crawler horse min-i-tractor 

grapple-skidder cable skidder cable yarder cable yarder-plusswing operation 
HORSE MINITRAC CRAWLER 

MINIMUM 

MAXIMUM 

Figure 6.-Logging system cost per cord 

CABLE 

SKlDDER 

GRAPPLE YARDER 

SKlDDER 

MEAN 
Technical Factors Affecting Skidding and 

Yarding Operations 

Although logging system productivity and costs 

are important considerations in determining the type of 

system to be used, technical factors may supersede 

these considerations. Important ones are terrain, 

environmental considerations, size of tract, type of cut, 

mean stand diameter, load capacity, skidding or yarding distance, and contract requirements. The effects of 

these factors on the suitability and economics of the 

six different logging systems are discussed in this 

section. 

Terrain. Tractor and skidder logging systems are 

severely handicapped when skidding uphill on slopes 

in excess of 10 percent (for each 1 percent of adverse 

grade, maximum payload volume decreases by 2.5 percent). For this reason, ground skidding is preferably 

done downhill to truck roads located in the valleys. On 

the other hand, most cable systems are rigged to yard 

uphill to truck roads located on the ridges or contours 

(Sundberg 1976). 

In addition to steepness of terrain, ground roughness and tractive capacity of soils affect the choice of 

logging method. Depending on the degree of these 

conditions, horses, tractors, and skidders can operate 

on a range of slopes as shown in Appendix, Table 7. 

Where slopes are excessively steep or rough, skid 

roads must be built for these systems to be used, and 

this increases costs. When the terrain is too steep and 

rough for ground skidding, cable yarding systems are 

to be preferred. 

Environmental issues. Soil erosion and sedimentation are the most serious environmental problems 

associated with timber harvesting. Patric (1978) states 

that the "soil erosion hazard is increased most when 

logging is conducted on steep slopes, in wet soils, and 

along streams. Highest rates of erosion usually occur 

on logging roads and skid trails." 

Section 208 of the Federal Water Pollution Control 

Act of 1972 requires the control of nonpoint sources of 

water pollution from forestry activities, including 

logging. The most direct approach for reducing soil 

erosion on timbered areas is to build as few roads as 

possible and to exercise all recommended guidelines 

for proper road construction, including erosion-control 

measures and revegetation after logging (Patric 1978). 

Selection of logging equipment and preplanning of 

road layouts affect the amount of area in roads and 

trails exposed to erosion. In mountainous terrain, 

wheeled skidders are noted for the dense road network 

needed to move logs to landings. An estimate of 

timber acreage logged per mile of road built in the 

central Appalachians was reported by Kochenderfer 

and Wendel (1978). Skyline yarders, for example, create 

the least disturbance in the forest. They can log about 

80 acres per mile of road constructed. For jammers the 

figure is about 31 acres, and for skidders, about 20 

acres. 

Ground skidding coupled with downhill logging 

results in more area disturbed and greater chance of 

erosion because the pattern of skid trails and roads 

tends to be fan-shaped with the apex at the bottom. 

Thus, water flows are concentrated and accelerated in 

their downhill movement. The opposite tends to be 

true with uphill logging methods, and they are preferable for that reason. However, one must consider the 

cost of building haul roads at midslope and ridgetop 

locations to accommodate these uphill logging 

systems. 

Size of tract. Too big or too small a tract of timber 

can limit a contractor's choice of logging systems. 

Timber contract termination dates set the time frame 

for harvest completion. On large tracts of timber, the 

obligation to meet the completion date more or less 

restricts the choice of logging systems to one of the 

higher production systems. On the other hand, tracts 

smaller than 30 to 40 acres are often considered too 

small for economic operation by whole-tree chipping 

contractors because moving in a big spread of equipment is too costly for the harvestable volume. 

Type of cut. Forest stands are subject to two 

principal kinds of cutting: partial cuttings and clearcuttings. Thinnings, timber stand improvement cuttings, and selection harvests-all partial cuts-are 

conducted in dense to well-stocked stands. In these 

stands, there is concern for potential damage to tree 

boles, tops, roots, and soil. Avoidance of stand damage often dictates that smaller, lighter, more maneuverable equipment be used. Where the terrain is relatively 

level, horses and miniltractors are appropriate. On 

moderately steep to steep terrain, small crawlers, small 

skidders, or small cable yarders are necessary. With 

the ability to control tree felling and placement, fallerbunchers have advantages over chain saws for partial 

cuttings in immature stands. And, although safer to 

use, they require considerably larger investments. 

Large rubber-tired skidders are better suited to 

clearcut harvests than to thinnings. A survey of 174 

Minnesota loggers in 1979 found that the chain-saw 

fellinglcable-skidder system was the most common 

type of operation reported in that state (Sinclair and 

Bolstad n.d.). It is also the most common in the central 

Appalachians. However, on both clearcut and partial 

cuts, skidders usually work from bulldozed skid roads 

on sites with slopes no greater than 40 percent 

(Gochenour and Hartman 1968). 
Small crawler tractors are an attractive alternative 

to wheeled skidders for salvaging bug-killed lodgepole 

pine. Working on steep, sensitive terrain in the Rockies 

of British Columbia, the crawler had less skid trail 

impact than rubber-tired skidders and operated at 

lower costs than cable systems. Furthermore, operators found that the crawlers were more stable on 

steep slopes, were not dependent on a large tractor for 

trail construction and clearing, and were available a 

higher percentage of time than were skidders 

(McMorland 1980). 

Mean stand diameter (MSD). Timber size has a 

direct bearing on equipment selection and productivity. 

For most logging systems, production rates are lower 

and costs are higher for small trees than for large trees 

(this is axiomatic within the logging industry). However, logging small timber can be profitable with systems employing faller-bunchers and grapple skidders. 

Berti (1984) found, for example, that faller-bunchers 

were essential in stands with harvestable trees averaging 10 inches or less in diameter at breast height 

(d.b.h.). In a 1979 study of Minnesota loggers, Bolstad 

and Sinclair (1981) reported that among 79 logging 

firms, mean productivity (in cords per man-hour) averaged 38 percent more for mechanical-fallerlgrappleskidder systems than for chain-saw felling1 

cable-skidder systems. 

Rubber-tired skidders and crawler tractors are 

available to handle all sizes of timber logged in the 

Northeast. Even the small crawler tractors reported in 

this paper handled loads comparable to those of cable 

skidders. Horses, mini-tractors, and small mobile 

yarders are more restricted in the size of logs they can 

handle, and this is directly reflected in their 

productivity. 

Load capacity. Load capacity is an important 

factor in selecting skidding and yarding equipment; it 

is a function of machine configuration and horsepower. 

Coupled with skidding distance, load capacity pretty 

well determines the potential productivity of skidding 

and yarding machines. Actual productivity, however, is 

more a function of how well machine load capacity is 

utilized, and that is directly related to the size, density, 

and number of logs hooked up for each turn from 

stump to landing. 

Data from some of the operations used in this 

study illustrate the point about load size per turn and 

machine load capacity. For example, Figure 7 shows 

that the average maximum load per turn for small (42 to 

78 hp) crawler tractors exceeds the average maximum 

load per turn for both cable and grapple skidders having more horsepower than the crawlers! The specific 

crawler-tractor operation involved (Adams 1967) was a 

thinning in second-growth Douglas-fir with a mean 

stand d.b.h. of 13.4 inches. The trees were large, and 

the logs were sizable-0.24 cords per log. The 65-hp 

tractors on this operation averaged 10 logs per turn, for 

an average load size of 2.45 cords. The 50-hp tractors, 

on the same operation, averaged six logs per turn for 

an average load of 1.47 cords. These two west coast 

operations increased the overall average load size per 

turn for all small crawler tractors to 1.05 cords per 

turn-close to the average load size for cable and grapple skidders. However, the median load size per turn 

for all eight small crawler-tractor operations (Appendix, 

Table 4) was 0.74 cords per turn-more typical of load 

sizes one would expect for small crawler tractors 

logging second-growth eastern forests. 

A similar example on the other extreme is the load 

size of the Bitterroot yarder working in Kentucky 

(Appendix, Table 6). Average loads of only 0.12 cords 

per turn were the result of the Bitterroot yarder's low 

mainline pull capacity (1,150 pounds). The only smaller 

load size in the data set was 0.09 cords per turn on a 

"logger's choicev2 operation logged with a horse in 

West Virginia (Appendix, Table 1). In contrast to these 

examples of small loads per turn, the minimum load 

size on mechanical-fallerlgrapple-skidder operations 

was 0.59 cords, almost six times the minimum loads of 

the Bitterroot cable yarder and horse operations. 

Skidding and yarding distance. On operable terrain, distance is the most important physical factor 

affecting skidding and yarding cycle times and, ultimately, productivity. On a particular logging chance, 

skidding and yarding distances can be good or bad 

depending on how much planning was done to provide 

the best combination of truck roads, skid roads, and 

landings for least total cost. Other factors to be 

considered in the planning process include volume and 

size of timber, skidding and yarding machines on hand 

or available, road construction feasibility, etc. Extensive determinations of this order, however, cannot be 

made on the basis of physical factors alone. They must 

include economic analyses based on the principles set 

forth by Matthews (1942). 

As a result of such analyses, it may be found that 

a combination of skidding and yarding machines may 

be the best solution. For example, if long skidding distances are required it may be that skidders, in combination with crawler tractors for short hauls, may give 

the lowest overall skidding cost. Or on steep terrain, 

uphill logging with jammers on contour roads, in 

combination with small crawler tractors logging downhill, may be the best mix of equipment for maximum 

production and lowest cost. Grafton3 points out that 

Logger cuts only trees yielding products he can sell. 

Personal communication. 
- 

HORSE MlNlTRAC CRAWLER 

MAXIMUM 

Figure 7.-Load size per turn 

animals and skidders are a potentially useful combination. He reports that in Zimbabwe, bunching logs 

with oxen or mules works well in combination with 

rubbe.r-tired skidders for the long skid distances. 

The efficiency and productivity of a skidding 

method depend on a combination of factors-some of 

which (load size and terrain) have already been discussed. Travel speed and hooking methods are also 

important, They are the principal factors in how fast or 

slow cycle times are. Rubber-tired grapple skidders 

have the advantage of good travel speed plus fast 

hooking and unhooking. These features and others 

CABLE GRAPPLE 

SKlDDER SKIDDER 

YARDER YARDER 

W/SWING 

EBZZE4 MEAN 

have made grapple and cable skidders the most 

popular skidding machines in the woods. However, 

there are harvesting situations where other machines 

are preferable. For example, in Holland, Leek and 

Schaafsma (1981) found that there is no need for skidders. Skidding can be done with horses or with agricultural tractors modified for logging. They recommend 

horses for thinning young stands where average skidding distances are 165 feet or less. Where skidding 

distances are greater, bunching with horses in combination with skidding by grapple-equipped tractors is 

recommended. 
Choices among skidding and yarding machines are 

difficult to make on a subjective basis alone. Selection 

of-machines for harvesting operations can begin with 

matching technical features to requirements of the job. 

But final selection should be based on a unit-cost 

analysis to determine break-even points among 

machines or combinations of machines for skidding 

distances, load size, and slopes that occur on the job. 

Contract requirements. Many roundwood and chip 

purchasers prefer to deal solely with large-volume producers. This is more efficient and less costly for them 

than dealing with numerous small producers. Thus loggers seeking contracts with these firms are limited in 

their choice of logging systems. Out of necessity, they 

must choose one of the more costly high-production 

systems or forgo producing for these buyers. 

The Effect of Economic Factors on 

System Selection 

The six systems represent a broad range of 

required inputs in manpower, invested capital, and 

necessary operating funds. The farmer and son who 

own a team of horses, a set of harness, and a chain 

saw can be in the logging business with the purchase 

of log chains and fuel for the saw, and the hire of a 

trucker to haul logs to markets. Though production 

may be only 4 to 6 cords per day, if they can cover outof-pocket costs and make wages for themselves, they 

are in business as loggers with a minimum outlay of 

capital. 

The other extreme in the logging business today is 

the large whole-tree chip logging contractor outfitted 

with a faller-buncher, grapple skidders, a whole-tree 

chipper, several chip trailers and highway tractors, plus 

a couple of support vehicles, maintenance equipment, 

and spare parts. Investment in such an equipment 

spread can total $750,000 or more. Operating with a 

contract to deliver large tonnages (200 to 300 tons) of 

pulp chips to the mill each day, the contractor must 

produce wood at a cost below current prices ($19 to 

$20 per ton) or go out of business. 

In the short run, a logging contractor must cover 

his variable costs of fuel, maintenance, and labor in 

order to stay in business. In the long run, the logger 

must also cover the fixed cost of his investment. The 

ability of a system to develop enough revenue to cover 

both fixed and variable costs is a necessary condition 

for equipment selection but is not the only condition 

governing equipment selection. Two other very important real-world economic questions are: (1) How much 

money can be obtained to purchase equipment, and 

what interest rate must be paid on this money? and (2) 

What degree of financial risk does the logger want to 

assume? 

The availability of funds is a critical factor in 

purchasing logging equipment since many banks are 

reluctant to lend money to logging contractors. This 

means that loggers must use their own funds to 

purchase equipment or must borrow money from 

secondary processors or equipment companies at 

above-average interest rates. The combined effects 

of low accessibility of funds and high interest rates 

reduce the amount of money a logging contractor will 

or can borrow and thus decrease the number of stateof-the-art logging systems used. The less capitalintensive systems, such as cable skidders, small 

crawler tractors, or even horses, may be employed 

instead of grapple skidders and faller-bunchers, even 

though their average cost per cord is higher. 

Owning logging equipment is risky because of the 

variability of timber markets and weather conditions. In 

idle periods or periods of reduced production, loggers 

who have borrowed money must still make payments, 

and loggers who invested their own money are losing 

the interest that money could earn in other investments. Risk emanates from capital or fixed costs 

rather than variable cost. Therefore, a logger may be 

more inclined to purchase a system with a relatively 

high variable cost and low fixed cost over a system 

with a high fixed cost and low variable cost. 

The risk problem is associated with cash flow of 

incoming revenue versus outgoing costs. The degree 

of risk an individual is willing to take depends on his 

own personality and the amount of time his equipment 

can remain idle before he can no longer afford to make 

payments on it. The risk factor, like the availability of 

money, tends to encourage the purchase of less 

capital-intensive systems even though the operating 

cost of these systems may be higher. 

Summary and Conclusions 

Harvesting is a key and expensive process in the 

transformation of standing timber into wood products. 

From the analyses conducted in this study, we can 

draw several conclusions about the effects of harvesting on future stumpage and roundwood supplies and 

prices in the eastern forest regions, and on the 

realities logging contractors face in choosing and 

using harvesting systems. 

With the exception of the cable yarder, the most 

efficient (lowest cost per unit of output) harvesting 

systems are the most capital-intensive systems. They 

are the systems with the highest fixed cost and the 

most risks for the contractors to finance and protect 

during unscheduled idle periods or periods of reduced 

production. The mechanical-fallerlgrapple-skidder 

system, the most capital intensive of current operating 
systems, produces wood at the least cost per unit but 

is restricted by steep and rough terrain. The implication for stumpage and roundwood supplies and 

prices is that as long as timber is available on sites 

accessible to mechanical-fallerlgrapple-skidder logging, 

stumpage prices will be firm and roundwood prices 

moderate. As less timber is available on accessible 

lands, average stumpage prices will edge lower, 

harvesting costs will go up because of lower productivity of systems employed, and roundwood prices will 

rise as far as market strength permits. 

Harvesting steep and environmentally sensitive 

lands will require the use of systems with lower 

productivity and higher unit costs. Stumpage prices for 

timber on these lands will be lower and contractors' 

revenues will be slimmer. If supplies of more accessible timber are sufficient to meet marketplace 

demands, less accessible timber will continue to go 

begging for a market. 

The realities of the timber marketplace and harvesting systems' production and costs present a real 

dilemma for the logging contractor. To achieve high 

output and low unit costs, he's driven to use capitalintensive systems that are costly to finance and risky 

to keep solvent in the face of long, unexpected idle 

periods due to log-buying suspensions, mill closings, 

and so forth. 

Loggers fortunate enough to have favorable longterm contracts and financing help from wood-using 

industries are those most able to employ capitalintensive, state-of-the-art logging systems. Loggers not 

so favorably connected must seek other options, such 

as more favorable financing arrangements, buying used 

equipment, andlor employing less costly systems. All 

logging contractors, regardless of system used, must 

strive for maximum production, while maintaining a 

tight rein on costs. 

A paradox of timber economics exists at the interface between stumpage supplies and harvesting costs. 

Higher stumpage prices and increased supplies are 

possible at lower harvesting costs. Lower harvesting 

costs are achievable with current harvesting technology-but at a price. The price is higher cost, 

capital-intensive systems that are restricted in use by 

the inability of loggers to finance them at "reasonable" 

risk, and by forestlands too steep, rough, or environmentally sensitive for these systems to operate on. 

Much of the forestland in the Appalachian Mountains, 

for example, is too steep for the highly productive 

mechanical-fallerlgrapple-skidder system. 

The challenge for future research as we see it is to 

develop financing arrangements that will allow loggers 

to invest in highly productive, capital-intensive systems 

with some protection against business failures due to 

the vagaries of weather, unstable markets, mill 

closures, and other causes of unscheduled idle 

periods. A second challenge for research is to develop 

state-of-the-art systems that will increase productivity 

and lower production costs on the steeper, rougher 

timberlands. 

Literature Cited 

Anon. Hay-powered logging on trial. LIRA. Rotorua, 

New Zealand: Logging Institute Research Assn.; 

1981; 6(3). 

Adams, Thomas C. Production rates in commercial 

thinning of young-growth Douglas-fir. Res. Pap. 

PNW-41. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest 

and Range Experiment Station; 1967. 35 p. 

Baumgras, John E.; LeDoux, Chris 6. Costs of harvesting forest biomass on steep dopes with a small 

cable yarder: results from field trials and simulations. In: Proceedings, Third Southern Biomass 

Energy Research Conference; 1985 May 12-14; 

Gainesville, FL. Gainesville, FL: University of Florida, 

Center for Biomass Energy Systems; 1985. 

Berti, Robert J. An assessment of biomass harvesting 

on small woodlots in New Hampshire. [Place of 

publication unknown]: [Publisher unknown]; 

1984. 51 p. 

Biller, Cleveland J.; Peters, Penn A. Testing a prototype 

cable yarder for tree thinning. Transactions of the 

ASAE. 25(4):901-905; 1982. 

Biltonen, Frank E.; Hillstrom, William A.; Steinhilb, Helmuth M.; Goodman, Richard M. Mechanized thinning 

of northern hardwood pole stands. Res. Pap. NC-137. 

St. Paul, MN: U.S. Department of Agriculture, Forest 

Service, North Central Forest Experiment Station; 

1976. 17 p. 

Bolstad, Kip; Sinclair, Steven A. Larger, mechanized 

loggers score highest productivity. Forest Industries. 

1 07(12):48-49, 1981. 

Brennan, Terry. Horse logging-an alternative. 

Northern Logger. 33(2):18-19; 1984. 

Brock, Samuel M.; Jones, Kenneth D.; Miller, Gary W. 

Costs of commercial thinning in yellow-poplar and 

upland oaks: a time study analysis for northern West 

Virginia. [Unpublished manuscript on file at West 

Virginia University, Morgantown, WV.] 1984. 17 p. 

Cubbage, Frederick W. Machine rate calculations and 

productivity rate tables for harvesting southern pine. 

Staff Pap. Series 24. St. Paul, MN: University of 

Minnesota; 1981. 16 p. 

Davis, Lawrence S.; Pabst, Heiner R. Hardwood pulpwood harvesting in western Virginia: costs and 

production requirements. Res. Pap. 114. Blacksburg, 

VA: Virginia Polytechnic Institute and State University; 1966. 16 p. 

Gochenour, Donald L., Jr.; Hartman, Robert L. How 

wheeled skidders work on 40% hardwood slopes. 

Canadian Forest Industries. 88(7):26-29; 1968. 
Hoffman, Benjamin F. Skidding with small tractors. 

Northern Logger. 28(10):18-20; 1980. 

Host, John; Schlieter, Joyce. Low-cost harvesting systems for intensive utilization in small-stem lodgepole 

pine stands. Res. Pap. INT-201. Ogden, UT: U.S. 

Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station; 

1978; 20 p. 

Huyler, Neil K. The cost of thinning with a whole-tree 

chip harvesting system. Northern Logger. 28(11):8-9, 

14, 28-29; 1982. 

Huyler, Neil K. The production potential and cost of 

the Vermont cable yarder. In: Proceedings, Industrial 

Wood Energy Forum '83; 1983 September 19-21; 

Nashville, TN. Madison, WI: Forest Products 

Research Society. [In press] 

Huyler, Neil K.; Koten, Donald E.; Lea, Richard V.; 

Quadro, Anthony P. Productivity and cost of three 

small fuelwood skidders. Journal of Forestry. 

82(11):671-674; 1984. 

Johnson, James A,; Hillstrom, William A.; Miyata, 

Edwin S.; Shetron, Stephen G. Strip selection 

method of mechanized thinning in northern hardwood pole size stands. Res. Note No. 27. Houghton, 

MI: Michigan Technological University; 1979: 13 p. 

Kochenderfer, J. N.; Wendel, G. W. Skyline harvesting 

in Appalachia. Res. Pap. NE-400. Broomall, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern Forest Experiment Station; 1978. 9 p. 

Leek, N. A.; Schaafsma, A. H. Methods and productivity 

standards for skidding in thinnings. Nederlands 

Bosbouw Tijdschrift. 53(10):315-321; 1981. 

McMorland, Bruce. Skidding with small crawlertractors. Tech. Rep. No. TR-37. Vancouver, B.C., 

Canada: Forest Engineering Research Institute of 

Canada; 1980. 89 p. 

Matthes, R. Kenneth; Watson, William F.; Clair, Oliver 

A. Production rate of rubber-tired cable skidders in 

Southern forests. Presented at 1976 Winter Meeting 

of the American Society of Agricultural Engineers; 

1976 December 14-17; Chicago, IL. St. Joseph, 

MI: American Society of Agricultural Engineers; 

1982. 18 p. 

Matthews, Donald Maxwell. Cost control in the logging 

industry. New York: McGraw-Hill; 1942. 374 p. 

Miller, Gary W.; Sarles, Raymond L. Costs, yields, and 

revenues associated with thinning and clearcutting 

60-year-old cherrymaple stands. Res. Pap. NE-582. 

Broomall, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station. 

1986; 8 p. 

Miyata, Edwin S. Determining fixed and operating costs 

of logging equipment. Res. Pap. NC-55. St. Paul, 

MN: U.S. Department of Agriculture, Forest Service, 

North Central Forest Experiment Station; 1980. 16 p. 

Patric, J. H. Harvesting effects on soil and water in the 

eastern hardwood forest. Southern Journal of 

Applied Forestry. 2(3):66-73; 1978. 

Putnam, Nathan E.; Kellogg, Loren D.; Olsen, Eldon D. 

Production rates and costs of whole-tree, tree-length, 

and log-length skyline thinning. Forest Products 

Journal. 34(6):65-69; 1984. 

Ruault, Bob. Small tractors successfully skid logs. 

Journal of Logging Management. 10(7):2040-2042; 

1979. 

Sarles, Raymond L.; Whitenack, Kenneth R. Costs of 

logging thinnings and a clearcutting in Appalachia 

using a truck-mounted crane. Res. Pap. NE-545. 

Broomall, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station; 

1984. 9 p. 

Sinclair, Steven A.; Bolstad, Kip. A profile of Minnesota 

loggers. St. Paul, MN: Department of Forest 

Products, University of Minnesota. 39 p. In.d.1 

Stuart, William B.; Rossie, Michael K. Production study 

of the Koller K300 cable yarder operating in the 

mountains of Virginia. In: Proceedings, Mountain 

Logging Symposium; 1984 June 5-7; Morgantown, 

WV. Morgantown, WV: West Virginia University; 

1984; 351-362. 

Sundberg, Ulf. Harvesting man-made forests in 

developing countries: a manual on techniques, 

roads, production and costs. Rome: Food and Agriculture Organization of the United Nations; 

1976. 185 p. 

U.S. Department of Agriculture, Forest Service. 1978, 

1979. [Unpublished data on file at Forestry Sciences 

Laboratory, Princeton, WV.] 

Wartluft, Jeffrey L.; Sarles, Raymond L. Fuelwood thinning-a marginal operation in West Virginia study. 

Northern Logger. 30(12):16-17, 28-29; 1982. 
Information cited in these tables was obtained from 

the following sources: 

1 Anonymous 1981. 

2 Adams 1967. 

3 Baumgras and LeDoux 1985. 

4 Berti 1984. 

5 Biller and Peters 1982. 

6 Biltonen and others 1976. 

7 Brennan 1984. 

8 Brock and others 1984. 

9 Davis and Pabst 1966. 

10 Hoffman 1980. 

11 Host and Schlieter 1978. 

12 Huyler 1982. 

13 Huyler 1983. 

14 Huyler 1984. 

15 Johnson and others 1979. 

16 McMorland 1980. 

17 Matthes and others 1982. 

18 Miller and Sarles 1985. 

19 Putnam and others 1984. 

20 Sarles and Whitenack 1984. 

21 Stuart and Rossie 1984. 

22 US. Department of Agriculture 1978,1979. 

23 Wartluft and Sarles 1982. 
Appendix 

Table 1.-Data for six horse logging operations 

Round- Load Capital System Production rate 

Type of Mean wood Skid./ size cost cost Cost 

logging Ref. Loca- Terrain Type stand product yard. per of Crew per Per Per Per 

system No. tion (% slope) of cut Species dia. harvested dist. turn equip. size day day man-day cord 

Draft 

horse: 

single 

team 

team 

single 

single 

single 

(22) WV mountainous 

(1) NZ 0 t050% 

(22) WV mountainous 

(9) VA & mountainwv ous 

thinning 

thinning 

selection 

loggers 

choice 

commercial 

clear 

cut 

clearcut 

oak NA 

hickory 

radiata NA 

pine 

oak NA 

cherry 

oak NA 

hickory 

oak NA 

hickory 

lodgepole 6.4 

pine 

-- 

tree 

lengths 

tree 

lengths 

saw logs 

tree 

lengths 

tree 

lengths 

tree 

lengths 

cord 

- 

$ cord cord 

a Range of values. \ 

b Mean value. 

CValue when skidding 400 feet. 

dTwo horses used alternately. 
Table 2.-Data for five mini-tractor logging operations 

Round- Load Capital System Production rate 

Type of Mean wood Skid.1 size cost cost Cost 

logging Ref. Loca- Terrain Type stand product yard. Per of Crew per Per Per Per system No. tion (% slope) of cut Species dia. harvested dist. turn equip. size day day man-day cord 

Minitractor: 

Pasquali 

986 21 

hP 

Pasquali 

991 24 

h P 

Pasquali 

993 30 

hP 

Forest 

Ant 12 

hP 

Holder 

A60 48 

hP 

(10) ME level but wl thinning 

undulating 

surface 

(23) WV mountain- thinning 

OUS 

thinning 

0 to 14% 

(14) NY slopes thinning 

scattered 

rock out- (14) NY / c,ps thinning 

spruce 

aspen 

oak 

hickory 

oak 

hickory 

oak 

hickory 

oak 

hickory 

in ft cord $ $ cord cord $ 

NA tree 400 .21 10989 2 171.04 4.78 2.39 35.78 

lengths 

7.1 tree 400 .17 1 1489 2 179.20 4.87 2.43 36.80 

lengths 

8.6 tree 400 .25 14467 2 195.76 5.52 2.76 35.46 

lengths 

8.4 tree 400 .38 12710 2 182.56 6.88 3.44 26.53 

lengths 

8.6 tree 400 .53 36177 2 271.84 13.36 6.68 20.35 

lengths 
Table 3.-Data for eight crawler-tractor logging operations 

Round- Load Capital system Production rate 

Type of Mean wood Skid./ size cost cost Cost 

logging Ref. Loca- Terrain Type stand product yard. Per of Crew per Per Per Per 

system No. tion (% slope) of cut Species dia. harvested dist. turn equip. size day day man-day cord 

Crawler 

tractor: 

42 hp 

50 hp 

65 hp 

65 hp 

65 8i 78 

h P 

78 hp 

42 hp 

42 hp 

wv 

WA 

WA 

wv 

Interior 

BC 

wv 

wv 

VA & 

wv 

0 to 33% 

0 to 40% 

0 to 40% 

0 to 65% 

0 to 80% 

0 to 37% 

0 to 23% 

mountainous 

thinning 

thinning 

thinning 

thinning 

thinning 

loggers 

choice 

diameter 

limit 

commercial 

clearcut 

oak 

hickory 

Douglasfir 

Douglasfir 

cherry 

maple 

lodgepole 

pine 

white 

pine 

oak 

hickory 

oak 

hickory 

tree 

lengths 

saw logs 

long logs 

(28'- 

40 ') 

long logs 

(28'- 

40 ') 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

cord 

.39 

1.47 

2.45 

.38 

1 .32 

.79 

.56 

NA 

cord 

9.44 

9.18b 

27.46 

27.1 1 

19.01 

11 .76b 

24.77 

40.76 

29.2gb 

33.89 

22.46b 

12.97 

cord 

4.72 

4.5gb 

13.73 

13.55 

9.50 

5.88b 

12.38 

20.38 

14.64b 

16.94 

11 .23b 

6.48 

a Mean value. 

bValue when skidding 400 feet. c Price of 65 and 78 hp tractors averaged. 
Table 4.-Data for ten cable.skidder logging operations 

Round- Load Capital System Production rate 

Type of Mean wood Skid./ size cost cost Cost 

logging Ref. Loca- Terrain TY pe stand product yard. Per of Crew per per Per Per 

system No. tion (%slope) of cut Species dia. harvested dist. turn equip. size day day man-day cord 

Cable 

skidder: 

90 hp 

90 hp 

90 hp 

90 hp 

90 hp 

90 hp 

75 hp 

100 hp 

125 hp 

70 hp 

mountainous 

0 to 10% 

0 to 36% 

0 to 23% 

0 to 45% 

0 to 26% 

flat to 

hilly 

flat to 

hiliy 

flat to 

hilly 

1 gO/oa 

thinning 

thinning 

thinning 

thinning 

selection 

diameter 

limit 

commercia1 

clearcut 

commercia1 

clearcut 

commercia1 

clearcut 

clearcut 

oak 

hickory 

cherry 

maple 

cherry 

maple 

cherry 

maple 

oak 

hickory 

oak 

hickory 

S. pine & ) 

hard- ) 

woods ) 

) 

) 

) 

1 

) 

': ) 

) 

) 

" ) 

) 

lodgepole ) 

pine 

7.5 

6.0 

N A 

N A 

N A 

N A 

Total 

pine & 

hardwood 

merch. 

& nonmerch. 

range 

2.5 to 

13.0 

6.4 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

tree 

lengths 

cord 

1.13 

1.53 

.70 

.72 

1 .O4 

1.62 

N A 

N A 

N A 

.59 

cord 

30.80 

20.02b 

20.96 

19.91b 

21.98 

16.43b 

17.41 

16.61b 

19.83 

l9.68b 

36.98 

30.22b 

24.94 

22.85b 

29.09 

27.02b 

33.25 

30.65b 

8.64 

cord 

15.40 

10.01b 

6.99 

6.64b 

7.33 

5.48b 

5.80 

5.53b 

9.91 

9.84b 

18.49 

15.11b 

12.47 

1 1.42b 

31.64 

10.81b 

11 .O8 

10.22" 

4.32 

a Mean values. 

b Values when skidding distance is 1000 feet. 
Table 5.-Data for nine grapple-skidder logging operations 

Round- Load Capital System Production rate 

Type of Mean wood Skid./ size cost cost Cost 

logging Ref. Loca- Terrain Type stand product yard. Per of Crew Per Per Per 

system No. tion (% slope) Per 

of cut Species dia. harvested dist. turn equip. size day day man-day cord 

Grapple 

skidders: 

(plus mechan.-fallers) 

2-90 hp (4) NH flat 

2-90hp (4) NH 3 to 15% 

2-120hp (4) NH flat 

2-120hp (4) NH 0 to 30°/o 

2-120hp (4) NH flat 

144hp (6) MI flat 

152hp (15) MI flat 

152 & (12) VT 5 to 25% 

1lOhp but mostly 

8 to 10% 

thinning white 

(in a plan- pine 

tation) I, red pine 

red pine 

salvage & 

thinning 

(nat. 

stand) 

weed & 

thinning 

(nat. 

stand) 

clearcut 

(nat. 

stand) 

thinning 

mixed 

hardwoods 

mixed 

northern 

hardwoods 

white 

pine 

maple 

thinning maple 

elm 

thinning northern 

hardwoods 

whole 

trees 

whole 

trees 

whole 

trees 

whole 

trees 

whole, 

trees 

whole 

trees 

whole 

trees 

whole 

trees 

whole 

trees 

aMean skidding distance. 

cord 

59 

.96 

1.01 

N A 

1.25 

1.48 

.89 

1.66 

1.79 

cord 

67.58 

72.90 

68.97 

49.70 

71.72 

111.52 

53.12 

95.82 

52.63 

cord 

22.53 

24.30 

22.99 

16.57 

23.91 

37.17 

26.56 

62.38 

17.54 
IU 

IU 

Table 6.-Data for nine cable-yarder logging operations 

Round- Load Capital system Production rate 

Type of Mean wood Skid./ size cost cost Cost 

logging Ref. Loca- Terrain TY pe stand product yard. Per of Crew per Per Per Per 

system No. tion (% slope) of cut Species dia. harvested dist. turn equip. size day _ day man-day cord 

Cable 

yarders: 

A. Jammers 

Appalachian 

thinner 

Truckmounted 

crane 

B. Skyline 

yarders 

Vermont 

Skagit 

SJ2 

Koller 

K300 

Bitterroot 

C. Skyline 

yarders 

wlswing 

operations 

Skagit 

SJ2 

Koller 

K300 

Bitterroot 

40 to 70% 

6 35% 

20 to 55% 

5 to 50% 

20 to 40% 

mountainous 

5 to 50% 

20 to40% 

15 t04O% 

thinning 

thinning 

thinning 

thinning 

commeroak 

hickory 

cherry 

maple 

northern 

hardwoods 

Douglasfir 

oak 

cia1 clearcut 

residue oak 

relog- yellowging poplar 

thinning Douglasfir 

commer- oak 

cia1 clearcut 

clearcut oak 

hickory 

NA tree 134a 

lengths 

6.5 tree 1503 

lengths 

8.5 tree 377a 

lengths 

12.8 log 60CF 

lengths 

10 to tree 328a 

12 lengths 

7.5 tree 285a 

lengths & 

logs up 

to max. of 

.26 cd. 

12.8 tree 60CF 

lengths & 

whole 

trees 

10 to tree 328a 

12 lengths 

NA tree 208a 

lengths & 

logs up 

to max. of 

.26 cd. 

cord 

.28 

.28 

.22 

.32 

.45 

.12 

.32 

.45 

.13 

cord 

15.68'J 

21.52 

11 .O7 

16.96 

22.67 

11.89 

17.93 

22.67 

11.64 

cord 

3.14b 

7.17 

3.69 

2.83 

5.67 

3.96 

2.56 

4.53 

1.94 

a Mean yarding distance. 

b Includes bucking and decking. c Maximum yarding distance. 
Table 7.-A selection guide for methods of log and tree extractions, given a range of terrain and soil conditions in 

temperate forestsa 

----------- Terrain and Soil Conditions - - - - - - - - ------------------ Skidding and Yarding Extraction Methodsb - - - - - - - - - - - - - - - - - - 

Relative 

Ground traction Slope Horse Mini- Crawler Cable Grapple Jammer g Skyline 

Steepnessc roughnessd capacitye direction tractor tractor skidder f skidder f yarder g 

Slopes 

< 10% 

Slopes 

11% to5O% 

Slopes 

> 50% 

smooth 

to rough 

very rough 

smooth 

t 0 

rough 

very rough 

smooth 

to 

rough 

very rough 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

good 

bad 

uphill 

uphill 

downhill 

downhill 

uphill 

uphill 

downhill 

downhill 

uphill 

uphill 

downhill 

downhill 

uphill 

uphill 

downhill 

downhill 

uphill 

uphill 

downhill 

downhill - 

a Adapted from scheme by Rudolf Meyr in Sundberg 1976. 

b When operating with normal loads. 

Refers to slopes longer than 150 feet; short slopes and pitches disregarded. 

d Refers to the occurrence or lack of obstacles more than 20 inches high; 

very rough includes numerous obstacles less than 10 feet apart. 

"Good" refers to friction soils; "bad" to cohesive soils. Practical local experience, 

taking into account season and precipitation, is included in this classification. 

Operating on adequately prepared skid roads. 

g These methods are designed for steep, rough slopes. On flat group or moderate 

slopes, they are suitable only if ground skidding is impractical, uneconomical, or 

restricted for environmental reasons. 

h X-Operations are suitable under stated conditions. i XX-Operations are possible under stated conditions. 
Sarles, Raymond L.; Luppold, William G. Technoeconomic 

analysis of conventional logging systems operating from 

stump to landing. Res. Pap. NE-577. Broomall, PA: U.S. 

Department of Agriculture, Forest Service, Northeastern 

Forest Experiment Station; 1986. 23 p. 

Analyzes technical and economic factors for six conventional 

logging systems suitable for operation in eastern forests. 

Discusses financial risks and business implications for loggers investing in high-production, state-of-the-art logging 

systems. Provides logging contractors with information useful 

as a preliminary guide for selection of equipment and 

systems. Discusses economic effects of harvesting systems 

on future stumpage prices and longrun supply of roundwood 

material. 

Keywords: Harvesting, logging, economics, systems analysis, 

equipment analysis 

*U.S. GOVERNMENT PRINTING OFFICE:1986-605-026:20044 

- 
Headquarters of the Northeastern Forest Experiment Station are in 

Broomall, Pa. Field laboratories are maintained at: 

Amherst, Massachusetts, in cooperation with the University of 

Massachusetts. 

Berea, Kentucky, in cooperation with Berea College. 

Burlington, Vermont, in cooperation with the University of 

Vermont. 

Delaware, Ohio. 

Durham, New Hampshire, in cooperation with the University of 

New Hampshire. 

Hamden, Connecticut, in cooperation with Yale University. 

Morgantown, West Virginia, in cooperation with West Virginia 

University, Morgantown. 

Orono, Maine, in cooperation with the University of Maine, 

Orono. 

Parsons, West Virginia. 

Princeton, West Virginia. 

Syracuse, New York, in cooperation with the State University of 

New York College of Environmental Sciences and Forestry at 

Syracuse University, Syracuse. 

University Park, Pennsylvania, in cooperation with the 

Pennsylvania State University. 

Warren, Pennsylvania.