USDA United States 

Department of 

Agriculture Performance of a Cut-to-Length 

Forest Service Harvester in a Single-Tree 

Northeastern 

Research Station and Group-Selection Cut 

Research Paper NE-711 

Neil K. Huyler 

Chris B. LeDoux 
Abstract 

Presents production and cost data for a mechanized cut-to-length harvester used 

in a single-tree and group-selection cut on the Groton State Forest in central 

Vermont. Tree volume or size is an important factor in machine productivity and. 

therefore, cost of production. For trees whose average volume (size) was 7 to 18 W. 

production ranged from 464 to 734 Wper productive machine hour. The cycle time 

for processing trees into bunches to forward to a landing ranged from about 1 

minute to 1.72 minutes per tree (average: 1.29 minutes). There was lile aboveground residual stand damage. The results should assist forest planners, loggers, 

and land managers in their decisionmaking. 

The Authors 

NEIL K. HUYLER, research forester, received a B.S. degree in forestry from West 

Virginia University in 1969 and a M.S. degree in industrial wood management and 

science in 1971. He joined the Northeastern Research Station in 1963, and 

currently is engaged in research on timber harvesting with sustainable forestry 

management concepts at the Station's laboratory in Burlington, Vermont. 

CHRIS 6. LEDOUX, supervisory industrial engineer, is engaged in forest 

engineering research at the Nottheastern Research Station in Morgantown, West 

Virginia. He received a B.S. degree in forest management from the University of 

Idaho, and M.S. and Ph.0. degrees in forest engineering from Oregon State 

University. He joined the Forest Service in 1983. 

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Introduction 

Mechanized cut-to-length (CTL) ha~&ing is becoming a 

popular alternative to traditional harvesting with a chai saw 

and ~~ ~ rubber-tired skidder LAraki 1994: Brinker 1990: Kelloaa 

1995). Studies have shown that the& is a high degree oiresidual stand damage and soil disturbance with 

conventional systems. There is considerably less residual 

damage with a CTL system because trees and/or logs are 

not pulled through the stand and trees can be felled 

directionally (Leech 1989; Tufts 1991). And because 

delimbing takes place in front of the machine and limbs and 

slash are used as a mat for the harvester and forwarder to 

travel on, soil disturbance and compaction are minimized 

(Pawlett 1985, Seixas 1995). Worker safety has been greatly 

improved with mechanized CTL harvesting, which is 

particularly effective in areas where there is a shortage of 

woods workers. Disadvantages of the CTL system are the 

high investment cost of the harvester and head, 

maintenance and repair costs related to the complex 

computerized electrical system, inability to handle hardwood 

stems larger than 22 inches in stump diameter, and the 

potential fire hazard from additional fuel loading. 

In this paper we report production and cost for a CTL 

harvesting system operating in a mixed stand on moderately 

rough and wet terrain on the Groton State Forest in central 

Vermont. Our primary objective was to evaluate the 

performance of a large machine in a singletree and group 

selection cut, and to assess the degree of residual stand 

damage. 

Study Area 

The study was a cooperative effort among the Northeastern 

Research Station, the Giles Champagne Logging Company, 

Colebrook, New Hampshire and the Vermont Department of 

Forest. Parks, and Recreation. The 42-acre study site is 

predominately a mixed hardwood stand interspersed with 

commercially unoperable sofhwmds, primarily balsam fir. 

Most of the hardwoods consisted of poor-quality, smalldiameter chipwood or pulpwood material (yellow birch and 

red maple). Several yellow birch sawlogs were scattered 

throughout the stand.The harvest objective was to 

encourage multiple-age classes to enhance the wildlife 

habitat for moose, snowshoe hare, and white-tailed deer. 

The preharvest basal area averaged 100 Wlacre with a 

mean stand diameter of 8 inches. Sawlog quality was fair to 

poor. Most of the hardwood competition was removed in the 

cut. A single-tree and group-selection (red spruce and 

balsam fir) cut was the primary silviculture treatment. Small 

overstory removals were conducted in areas with dense 

balsam fir regeneration. 

Soils were extremely wet in some areas and poorly drained 

in most of the remaining areas. Because of these extreme 

conditions and little or no slope, it was thought that winter 

logging with a CTL system would best achieve our 

objectives. 

Equipment 

The CTL harvester (also called a feller processor) is a 

Tirnbco Model T425' tracked excavator-type machine 

integrated with an Ultimate 5600 single-grip processor head. 

This harvester is designed to cut and delimb the tree and 

buck the stem to length in the stand. The harvester has cab 

leveling capability and can operate on moderate slopes, in 

wet areas, and in tight selective cuts (Fig. 1). The single-grip 

head has a maximum cutting diameter of 22 inches and a 

limbing diameter of 2 inches to 10 inches. The volume 

removed from the site was estimated from a 100- percent 

timber cruise. Each tree was marked with tree paint, 

measured, and tallied; 91 1 trees were marked as sawlog 

trees and 2,081 stems were marked as pulpwood trees 

(Tables 1-2). 

'The use of trade. firm. or CorDoration names in this report is 

for the information and convenience of the reader. such use 

does not constitute ~~ ~~~~ an official endorsement bv the U.S. 

Department of Agriculture or Forest Service if any product 

or service to the exclusion of others that may be suitable. 
Figure 1 .-4TL harvester operating in mixed hardwood and softwood stand. 

The Studv circular chain saw-type cutting head. The tree was then 

The study was divided into two phases. Phase 1 included 

cutting and processing individual trees and forwarding the 

cut-to-length material to the landing.The system on the site 

also included a Franklin forwarder and slasher at the 

landing. The operator of the forwarder had just begun job 

training, so no time data were recorded for the fotwarderl 

slasher. In phase 2 we estimated residual stand damage 

caused by the ha~eSter.Ten prism plots (10 BAF) were 

established prior to harvest and then reentered postharvest 

to measure and record any stem andior root damage. These 

data will be analyzed and reported in detail in a future 

report. 

The sequence of events for the CTL harvester was as 

follows. The operator scanned the area for marked treeszand 

positioned the processing head on the tree to be cut. The 

accumulator arms gripped the tree while cuning it with the 

*Most of the trees had to be remarked higher on the tree (10 

to 12 feet up the stem) so that the harvester could see the 

paint marks. 

turned horizontal to-the ground and spiked feed rolls pulled it 

through delimbing knives to remove limbs. The operator then 

cut the stem to length, usually 8 feet for pulpwood and 12 to 

16 feet plus 4 inches for trim allowance for sawlogs. The cut 

stems were placed into bunches or piles of pulpwood and/or 

sawlogs. The bunches later were picked up by the forwarder 

and taken to the landing. The operator had little opportunity 

for merchandizing. Spruce-fir that was 8 inches and larger 

were marked for sawlogs; hardwoods that were 12 inches 

and larger generally were marked as sawlogs. 

Time and motion data were recorded over a Bday period to 

determine the delay-free total cycle time for a range of tree 

volumes.Total cycle time includes cutting the stem, 

delimbing, cuning the stem to length, piling, and travel time 

to the next stem. We recorded the total number of trees per 

bunch, the volume of each tree, and the time required to 

create the bunch. Timing began when a tree was cut to 

create a bunch and ended when a new bunch was started. 

The number of trees was recorded for each bunch along 

with the length and smalkand large-end-diameter of each 

piece in the bunch. 
Table 1.-Sawlog volume by species, number of trees and volume per tree 

Number 

Species/product Volume of trees Volume/tree 

Board feet Board feet 

Sprucelfir 67,730 727 93 

Yellow birch 12,080 105 115 

Red maple 4,120 37 111 

Sugar maple 1,660 19 87 

White b~rch 1,600 23 69 

Total or average 87,190 91 1 95 

Table 2.-Pulpwood volume by species, number of trees, and volume per tree 

Number 

S~ecies Volume of trees Volumeltree 

Cords Cords 

Hardwood 27g 1,759 6 

Softwood 35 322 9 

Total or average 691 2,081 7.5 

Results 

The average volume per bunch was 66.19 W. The average 

piece size within the bunch was 5.6 inches at the small end 

and 7.07 inches at the large end. The mean length of the 

pieces was 10.6 feet. Each bunch contained about 4.9 trees 

with an average volume of 13.4 W per tree. 

The CTL harvester produced 523 ft3 of material per 

productive machine-hour (PMH) with a range of 463 to 734 

ff ~. oar -- PMH. The harvester cut about 47.48 trees Der PMH ~ ~~ 

. ~~ 

(range: 35 to 56 trees per PMH).The average delay-free 

cycle time to travel to the tree, cut and delimb it, and cut the 

stem to length was about 1.29 minutes per tree (range: 1 .Ol 

to 1.72 minutes). This is consistent with similar sitesas 

reported by the operator where 350 to 450 trees are 

harvested per day. 

Several factors that may influence the productivity of the 

harvester include tree size, species (hardwood or 

softwood), branchiness andlor size of branches, 

topography, and operator skill. We analyzed tree size to 

determine its effect on machine productivity. The data 

indicated a significant relationship between tree volume 

(size) and cubic feet of production (R2 of 86 percent). The 

influence of tree size on machine productivity per PMH is 

shown in Figure 2. 

Estimated daily and annual production for the CTL harvester 

over a range of tree volumes are shown in Tabie 3. At an 

average tree size of 16 W, daily production is about 4,933 fP 

per PMH. Assuming an average machine utilization rate of 

80 percent, the annual production for the same tree size 

totals 986,600 W. Estimated hourly owning and operating 

costs for the CTL system are shown in Table 4. These 

include fixed, variable, and labor costs for scheduled hours 

(SMH) and PMH. With regard to the latter, the total fixed cost 

was $60.29 per PMH and the total variable cost was $51.23 

per PMH. This is typical for a machine that requires a high 

capital investment. When the labor cost of $35 per PMH is 

added to the other costs, the total owning and operating cost 

of the CTL harvester is $146.52 per PMH.The owner 

estimated that $80 per PMH should be added for forwarding 

the material to the landing. 

Figure 3 shows the influence of tree size on the cost of 

production. As size increases, the cost of production 

decreases; however, as tree size approaches the limitation 

of the machine, the cost rises at an increasing rate. In our 

study, large trees were felled manually with a chain saw and 

skidded to the landing with a cable ~bber-tired skidder. As a 

result, the machine's limitation was not reached so there is 

no indication of the cost increasing at an increasing rate. 

Also, it should be noted that when young to mature 

hardwoods are being harvested, the heavier hardwood trees 

cause excessive wear on the processing head over time. 
Tree Volume (R) 

Fbum 2.--€ikI of tree size on CTL harvater. 

7 8 9 10 11 12 13 14 15 16 17 18 

Tree Size (ff) 

Figure %-Effect of tree size on cost. 
Summary 

The study results indicated that the CTL system wuld be an 

effective hamtino tool in the Northeast Preliminarv 

analysis of residua? stand damage on the site reveal& only 

2 percent of the residual trees had atem wounds with wood 

exposed. These generally were wounds to the fitst log that 

probably were caused by the feller head. These wounds did 

not exceed 20 percent of the stem, according to Ron Kelly, 

brest protection specialist, with the ~emwnt~~e~arlment of 

Forests. Parks. and Recreation. Kelh, rewrted that 14 

percent of the ksidwl trees had mi w&nds that probably 

were caused by the fomarder: all root wounds were confined 

to one side of the tree. The analysis indicates that the CTL 

systemcsusegfewerroo(andstemmxndsthan 

conventional harvesting systems. me CTL hamster/ 

processor ah is Wi. it can be used as a fe4ler only and 

combined with a grapple slddder for whole-trw logging, or 

can fell the trees and delimb them and, with a cable or 

@apple skidder, be a part of a MClength Wng system. 

W~JI inxessing emphasis on sustainable fwest management 

and the ability to meet the regulations for Best Management 

Practices, that are required in most slates, the CTL harvester 

can assist in making forest management and business . . declsrons with cespect to lenglhening the normal OPe~ati~ 

season, stabiliuing production, and low inventory volumes. 
Literature Cited 

Araki. Dennis, R. P. F. 1994. At-the-stand and roadside log 

processing in Alberta: a comparision. Spec. Rep. No. 

5R-96. Vancouver. BC: Forest Engineering Research 

lnstitute of Canada, Western Division. 29 p. 

Brinker, Richard W.; Tufts, Robert A. 1990. Economics of 

cut-to-length harvesting system in second thinning. 

In: Managing forestry operations in a changing 

environment. Proceedings of the 13th annual meeting of 

the Council on Forest Engineering; 1990 August 12-16; 

Outer Banks, NC. Raleigh, NC: North Carolina State 

University, College of Forest Resources. 

Gingras, J. F. 1994. A comparison of full-tree versus cutto-length systems in Manitoba Model Forest. Spec. 

Rep. No. SR-92. Point-Claire, PO: Forest Engineering 

Research lnstitute of Canada. 16 p. 

Green, Dale, W.; Lanford, Bobby L.; Stokes, Bryce J. 1984. 

Productivity of the Valmet 940 Gp grapple processor 

in southern pine plantation thinning. In: Proceedings of 

the Council on Forest EngineeringIlUFRO; 1984 August 

11-18; Orono, ME. Orono, ME: University of Maine: 105- 

108. 

Kellogg, Loren D.; Brown. Cameron G. 1995. Using a 

single-grip harvester and skyline yarding system in a 

forest health improvement application. In: 

Sustainability, forest health & meeting the nation's needs 

for wood products. Proceedings of the 18th annual 

meeting of the Council on Forest Engineering; 1995 June 

5-8; Cashiers, NC. Raleigh, NC: North Carolina State 

University, College of Forest Resources: 130-142. 

Leech, Peter E. 1989. Rottne log-length logging system. 

In: Stokes, Bryce J., ed. Proceedings of the Southern 

Regional Council on Forest Engineering: 1st annual 

meeting; 1989 May 3-4; Auburn, AL. New Orleans, LA: 

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

Forest Experiment Station: 88-96. 

Meek, Philippe. 1995. Concentrating on a slash 

distribution solution. Canadian Forest Industries. JulyAugust: 46-49. 

Pawlett. Steve. 1985. Swedish harvesting system debuts 

in New Brunswick. Canadian Forest Industries. 105(10): 

13-14. 

Seixas, Fernando; McDonald. Timothy P.; Raper, Randy L. 

1995. Effect of slash on forwarder on soil compaction. 

In: Sustainability, forest health & meeting the nation's 

needs for wood products. Proceedings of the 18th annual 

meetmg of the Co~nc~l on Forest Engmeer~ng. 1995 June 

5-8 ~, Cash~ers NC Rale oh. -. NC horth Carolma State 

University, College of Forest Resources: 77-86. 

Tufts, Robert A. 1991. Productivity and cost of the Norcar 

600 harvester. In: Proceedings of the ASAE forestry and 

environmental conference; 1991 June 5-6; New Orleans, 

LA. St. Joseph, MI: American Society of Agricultrural 

Engineers: 85-92. 
Huyler, Neil K.; LeDoux, Chris. 1999. Parformance of a cut-to-length harvester 

in a single-tree and groupselaction cut Res. Pap. NE-711. adn nor. PA. U.S. 

Department of Agriculture, Forest Servlce, Northeastern Research Statlon. 6 p. 

Presents production and cost data for a mechanized and cut-to-length (CTL) 

harvester used in a single-tree and groupselection cut on the Groton State Forest 

in central Vermont. For trees whose average volume (size) was 7 to 18 W. 

production ranged from 464 to 734 W per productive machine hour (PMH). The 

cycle time for processing trees into bunches lo forward to a landing ranged from 

about 1 minute to 1.72 minutes per tree. There was lime above-ground residual 

stand damage. The cost of the CTL harvesting system was $146.72 per PMH. 

Keywords: harvesting, production, costs, cut-to-length 

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Headquarters of the Northeastern Research Station is in Radnor, 

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Parsons, West Virginia 

Princeton, West Virginia 

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

College of Environmental Sciences and Forestry at Syracuse University 

Warren, Pennsylvania 

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