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Building and Environment 42 (2007) 2107–2113

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Productivity and costs in the course of timber transportation with theKoller K300 cable system in Turkey

Necmettin Senturk, Tolga Ozturk�, Murat Demir

Department of Forest Construction and Transportation, Faculty of Forestry, Istanbul University, 34473, Bahcekoy/Sariyer/Istanbul, Turkey

Received 25 January 2006; received in revised form 28 February 2006; accepted 9 March 2006

Abstract

This study was carried out on very steep and difficult terrain. Whole trees were logged uphill to the forest road by a Koller K300 cable

crane. Investigations were carried out by time studies for which the repetition time measurement method was selected. Through time

studies, the productivity and cost of the Koller cable system were evaluated.

Koller K300 cable system’s time of transportation for one time from distance 100, 200 and 250m arranges the average 6.24, 8.05 and

10.10min in the Salalet Hill felling area. The productivities of Koller K300 cable system at these different distances were found as 6.6m3/h

(100m), 5.5m3/h (200m) and 4.9m3/h (250m). The average load is two piece timbers. The cost of the Koller K300 cable system was

found as $4.2 per m3. Operation phases most effective on total time and productivity were determined as lateral outhaul, hook and

inhaul. The felling sequence should be chosen with consideration for efficiency, wireless should be used between yarder operator and

choker setters for communication, and much more chokers should be used for loading. Further yearly working times of machines should

be increased.

r 2006 Elsevier Ltd. All rights reserved.

Keywords: Koller K300; Cable system; Carriage; Productivity; Cost; Logging

1. Introduction

Forest transportation should be considered in twostages. The first one is called primary transportation,which covers all activities from felling to the landings, andthe second one is called secondary transportation, whichcovers hauling activities between landings and sawmills.The extraction of forest products from compartments is avery difficult, expensive and time-consuming operation.This problem is very important because the forests ofTurkey are located in mountainous areas. The extraction offorest products without loss of quality and quantity is animportant problem.

e front matter r 2006 Elsevier Ltd. All rights reserved.

ildenv.2006.03.005

ing author. Tel.: +90 (212) 2261100x25291;

261113.

esses: nsenturk@istanbul.edu.tr (N. Senturk),

ul.edu.tr, tozturk1972@yahoo.com (T. Ozturk),

ul.edu.tr (M. Demir).

Turkey has 20.7 million ha of forests, which makes up26.6% of its total land area. Approximately 75% of theforested area is on steep land with slopes greater than 40%.Due to this, harvesting in mountainous regions has alwaysplayed a significant role. In the last 30 years Turkey’sforests have been provided with a partial road network.The need for total forest roads in Turkey was 201 810 km,the 133 693 km portion of which, corresponding to 66.25%,was constructed by the end of 2004 with a view of beingcapable of conducting modern forestry activities with asystematic roads network by completing as soon aspossible the construction of the remaining portion of suchroads. Road density is 10.7m/ha in Turkey’s forests [1,2].The transportation of forestry products can be divided

into two stages. The first stage is primary transportation,which involves the haul of timbers. The second stage issecondary transportation, which involves the transport oftimbers, generally realized by trucks on forest roads [3].The productivity of forest harvesting depends on various

ecological factors and their positive and negative effects.

ARTICLE IN PRESSN. Senturk et al. / Building and Environment 42 (2007) 2107–21132108

Primary transportation is currently done at three differenttypes in Turkey’s forestry. These are human power, animalpower and mechanization. Ground skidding by man andgravitation is applied in small forest areas for theextraction of a small amount of timber and a large amountof fuelwood over short distances. Animal skidding, mainlyby horses and oxen, is used for pre-skidding for distancesbetween 20 and 100m. Mechanical skidding is carried outby tractors of all types. Cable systems are used for primarytransportation and these are Gantner, Koller and URUScable systems [4]. Rubber-tire skidders are a provenmethod of logging for both efficiency and cost effective-ness, even on moderate slope conditions. On steeper slopes,however, road costs, environmental impacts and loggingcosts increase significantly [5].

With regard to logging practice by the Koller K300yarder in the Artvin region, the productivity values fortransportation of softwood, hardwood, and firewood weredetermined as 4.997, 4.755, and 4.620m3/h (6.6 stere/h),respectively. Furthermore, the cost of extraction of timberwas calculated as $6.642 per m3 for transportation ofsoftwood, $6.86 per m3 for transportation of hardwoodand $7.048 per m3 ($5.321 per stere) for transportation offirewood [6]. The production rates and costs of harvestingsmallwood were determined for the Koller K300 operatingunder variable conditions: size of crew, addition of askidder to swing logs from the landing and type of harvestmethod employed, either conventional or hot thinning(simultaneous felling and yarding of whole trees). Theslope of skyline and height of carriage is important forshort distance skylines for log transportation [7]. In thestudy of Huyler et al. [8], the productivity of Koller K300yarder is calculated as $65.92 per hour. This study wascarried out in the forest of Massachusetts Beartown andthe slope of the area is determined as between 40% and65% [8]. Another study was carried out at the Massachu-sette Beartown by Ledoux et al. in 1997. The haulingdistance of the Koller K300 cable system is 120m and thedistance of lateral dragging is 8m. Productivity of theKoller K300 cable system is determined as 11.760m3/h [9].

This paper deals with the research of primary transpor-tation of timbers by the Koller K300 cable system. Thepurpose of this research is to contribute to a growingknowledge of the productivity of a Koller K300 cablesystem in timber extraction from Turkey’s mountainousforests. This study reports on the productivity, cost andfuel consumption of Koller K300.

Table 1

Characteristics of study area

Characteristics Study site-1 Study site-2 Study site-3

Forest district Salalet Salalet Salalet

Compartment number 46 46 46

Altitude 1440 1450 1460

Aspect northwest north northeast

Number of workers 5 5 5

2. Materials and methods

2.1. Materials

This study was conducted and analyzed in the Artvinregion of Turkey and this region has dense forest areas.Extraction studies with the Koller K300 cable system wererealized in three different sites in the Salalet forest districtof Artvin (Table 1). The stand contained a mixture of Picea

orientalis (L.) Link. Abies nordmanniana (Stev.) Mattf. andPinus sylvestris (L.). The Koller K300 cable system wasinstalled to three different points in the felling area. Theaverage altitude of felling area is 1450m and the averageslope gradient is 45%.In the district where this study was carried out, the location

named Kec- i Sırtı represents the minimum elevation with1300m above sea level, while Salalet Hill represents themaximum elevation with 1671m above sea level. Accordingto the measurements made in the production area, theaverage slope of land is 55%. The minimum slope wasmeasured to be 25% while the maximum slope was 100%.The road density in the area is 14m/ha.The Koller K300 cable system is a mobile cable-yarder

system designed for uphill logging (Fig. 1). The machine iscompact with simple engineering, and designed for smallwood logging and residue removal operations. The cablesystem could be mounted on a farm tractor with a three-point hitch or could be placed on a trailer for easytransportation over long distances [9]. The system compo-nents and capabilities are: (1) the tractor engine must havea minimum of 50 hp, (2) the approximate weight withoutthe tractor is 1580 kg, (3) the average mainline speed for thetractor-mounted version is 192m per minute, (4) cablecapacity is 300m of 9.5mm cable for the mainline, 300m of16mm cable for the skyline and 30m of 14mm cable forthe guyline, (5) uses multispan self-clamping carriage andcan be set up with intermediate supports and tailspar, and(6) the tower height is 7m [9,10].Six workers are employed in operating the cable system.

The time of installation of the cable system is 3–5 h whilethe uninstallation time is 1–2 h. The number of safety ropesranges between 2 and 4 [11].

2.2. Method

In this study, the method of repetition measurement oftime was employed. The complete timber haul operation

Characteristics Study site-1 Study site-2 Study site-3

Hauling way Uphill Uphill Uphill

Average field slope 60 55 45

Length of cable 300m 250m 270m

Kind of timber Spruce Spruce Spruce

Hauling distance 250 200 100

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Fig. 1. Koller K300 cable system.

N. Senturk et al. / Building and Environment 42 (2007) 2107–2113 2109

performed in this study using the cable system describedabove consists of six stages enumerated below. The timerequired for completion of each stage was measured by achronometer. The equipment used in the application of themethod employed in carrying out the time studies involvedin this work are the time-study recording disc, time-studyforms and chronometers [3]. A detailed time and motionstudy was conducted using the repetition-timing method todetermine the total yarding cycle times, which is theamount of time it takes the carriage to travel from thelanding and unhook the payload. Six yarding elementswere identified and timed to determine the total cycletime [9].

(A)

Outhaul empty: Begins when the operator is ready tomove the carriage from the landing out to the landingout to the choke setter, and ends when the choke settertouches the choke.

(B)

Lateral out: Begins at the end of outhaul empty andends when the choke setter is ready to hook a turn.

(C)

Hookup: Begins at the end of lateral out and endswhen the choke setter has completed hooking thechokers and signals to begin yarding.

(D)

Lateral in: Begins at the end of hookup and ends whenthe turn is pulled up to the carriage and begins to moveup the corridor.

(E)

Inhaul: Begins at the end of lateral in and ends whenthe turn has reached the position on the deck where itcan be directly unhooked at the landing.

(F)

Unhook: Begins at the end of inhaul when the carriagepasses over the tripblock and ends when the chokershave returned to the carriage [9].

The time data were recorded by two persons who weretrained in repetition timing study techniques. One person

was stationed in the timbers at the hookup location and thesecond person was stationed next to the Koller K300 cablesystem. Communication between these persons was main-tained by wireless. In the study process, 65 total cycle timeswere recorded, which comprised the database for the cycle-time regression analysis.In addition to the total hauling cycle time, delay time

must be considered. Delay time is important to theharvesting operation because it has a direct impact on thefinal cost of production. The cause of each delay at thisstudy was recorded. Four categories of delays were used inthe delay analysis as follows: (1) mechanical delays, (2)operational delays, (3) nonproductive delays and (4)weather condition delays, which represent delays asso-ciated with the principal operating functions of the system.In addition to the hauling delays, the following hauling

variables were recorded and summarized:Skyline installation distance: The ground slope distance

in meters was measured and marked at regular intervals toaid in recording slope distance that the carriage traveledduring the study period.

Lateral distance: The lateral hauling distance in meterswas measured either by pacing the distance or by ocularestimation of the distance to the nearest 3m.

Volume: Each piece was measured in the corridor andmarked; these data were recorded. The timber diametersand length were scaled and recorded on a form.In that district, production operations were carried out

using a Koller K300 cable system for a total of 2 months,namely July and August, during a year, hauling a total of2100m3 timber. The 94% of total production realized inthe district was transported by the forestry cable system.

3. Results and discussion

The Salalet Hill District operating under the manage-ment of Taslica Forestry Operations office was chosen asthe study area for timber haul operations. In three differentlocations of the production district, a Koller K300 cablesystem mounted on tractor was used (Fig. 2).The average times of timber haul for the Koller K 300

skylines installed in three different locations in the districtare shown in Table 1, while the share of time taken by eachstage of operation in the total time is shown in Fig. 3.Timber transportation was made from three different

distances and time measurements were made at thesedistances. A Koller K300 cable system’s time of transpor-tation for one time from distance 100, 200 and 250marranges the average 6.24, 8.05 and 10.10min in the SalaletHill felling area. Productivities of the Koller K300 cablesystem at these different distances were found as 6.6m3/h(100m), 5.5m3/h (200m) and 4.9m3/h (250m). Theaverage load is two pieces. The results of time measure-ments are shown in Table 2. The volume of an averagepiece of timber was 0.375m3 and it was 5m long.

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Fig. 2. Koller K300 cable system at the Salalet Hill production forest.

A B C D E F 100200

2500

0.5

1

1.5

2

2.5

3

3.5

Ave

rag

e ti

me

(min

)

Transporting phasesTransportin

g

distance (m)

Fig. 3. Distribution of time measuring phases on total time.

N. Senturk et al. / Building and Environment 42 (2007) 2107–21132110

The average lost time is changed between 1.00 and1.50min per phase. Lost times were taken from differentpoints in working area. These points are loading area,unloading area and defect of carriage during transporta-

tion on the main line. The cost of the Koller K300 cablesystem was found as $4.2 per m3. Daily fuel consumptionwas measured by volume method. The average fuelconsumption per operating hour is approximately 2.5 l/h.

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Table 2

The average work time obtained in Salalet Hill harvesting area with Koller K300 cable system

Hauling

distance (m)

Lateral

dragging (m)

Transportation phasesa Volume (m3) Fuel cons. (l/h) Hours

productive

(m3/h)

A B C D E F G

100 21 0.19 2.49 0.30 1.06 1.04 0.26 6.14 0.688 2.0 6.60

200 18 0.34 2.17 0.37 1.12 2.44 0.42 8.05 0.733 2.5 5.50

250 20 0.32 2.28 0.56 1.38 3.14 1.21 10.10 0.827 2.5 4.90

a(A) Outhaul empty, (B) lateral out, (C) hookup, (D) lateral in, (E) in haul, (F) unhook, (G) total time.

Fig. 4. Koller cable system work phases average in Salalet Hill harvesting area: (A) outhaul empty, (B) lateral out, (C) hookup, (D) lateral in, (E) inhaul,

and (F) unhook.

N. Senturk et al. / Building and Environment 42 (2007) 2107–2113 2111

The Koller K300 cable system was mounted on a 1180DTH tractor. In operating the cable system, a total of sixworkers, one operator in the upper station, two workers atthe loading station, two workers at the unloading stationand one wireless operator in the lower station, wereemployed. All workers employed at skyline operationswere housed in the barracks located within the forest area.Dispersion of work phases is shown in Fig. 4.

A corridor of average 2m wide was opened for eachinstallation of cable system. The tower of the cable system,located at the upper station, was fixed by tying to threetrees by three safety ropes. In the lower station, the mainline was tied to two trees one behind the other.

Regression analysis was performed on the Koller K300time study data to develop a delay-free cycle time equationfor the machine under the stand conditions stated in thestudy. The variables included transportation distance,

lateral yarding distance, volume per turn in cubic meterand timber number. Enter method was done for regressionanalysis of different transportation distances. The cycletime equations calculated for the Koller K300 took thefollowing form:

For 100 m transportation distance:

Cycle time ðin minÞ ¼ 2:142þ 0:06� Tdþ 0:857� V

þ 0:064� Tnþ 0:129� Ld;

R2 ¼ 0:80.

For 200 m transportation distance:

Cycle time ðin minÞ ¼ 3:592þ 0:001� Tdþ 1:440� V

þ 0:300� Tnþ 0:158� Ld;

R2 ¼ 0:70.

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For 250 m transportation distance:

Cycle time ðin minÞ ¼ 6:406� 0:011� Tdþ 2:198� V

þ 1:006� Tnþ 0:139� Ld;

R2 ¼ 0:64,

where Td is the transportation distance (in m), V thevolume (in cm3), Tn the timber number and Ld the lateraldistance (in m).

The SPSS 11.5 statistical programme has been appliedand, according to its series of phases: (A) outhaul empty,(B) lateral out, (C) hookup, (D) lateral in, (E) inhaul and(F) unhook; these series are independent variables. Thedependent variable is total time (G). Regression analyseswere done with the stepwise method between independentvariables (Fig. 5). The most effective variables, with 99%confidence intervals, are:

For 100 m transportation distance:

G ¼ 0:463þ 1:046� Bþ 1:056�D

þ 3:949� Aþ 2:102� F þ 0:654� E,

R2 ¼ 0:98; F ¼ 85:150; Durbin2Watson ¼ 1:966.

For 200 m transportation distance:

G ¼ 1:304þ 0:975�Dþ 0:952� B

þ 1:036� F þ 0:904� E þ 2:449� A,

R2 ¼ 0:99; F ¼ 449:549; Durbin2Watson ¼ 1:773.

For 250 m transportation distance:

G ¼ 1:143þ 0:959� Bþ 1:026� F

þ 1:029�Dþ 1:102� C þ 1:007� E,

R2 ¼ 0:99; F ¼ 404:109; Durbin2Watson ¼ 2:312.

Durbin–Watson coefficient values were found as 1.966,1.773 and 2.312. If this coefficient is near 2 or above, thismeans that there is no autocorrelation between theindependent changeable that form the model, which arecompletely separate from each other.

y = 0.0255x + 3.2816

2

4

6

8

10

12

14

16

50 100 150 200 250 300

Transporting distance (m)

Tota

l tim

e (m

in)

Fig. 5. Transportation times on main line. *Total time of work phases.

4. Conclusions and recommendations

Operation phases most effective on total time andproductivity were determined as lateral outhaul (B), inhaul(E) and lateral in (D). The felling sequence should bechosen with consideration for efficiency, wireless should beused between yarder operator and choker setters forcommunication, and much more choker should be usedfor loading. Further yearly working times of machinesshould be increased. A 100m transportation distance wasfound as most productive (6.6m3/h). We observed thatlong transportation distance caused decreases in harvestingproductivity.The results of this study have shown that the transporta-

tion of forestry products by mobile cable systems operatedin mountainous terrain that is not accessible by forestroads. The cable system is a more permanent and efficienthaul method in mountainous forest land when combinedwith forest roads, since it enables side drawing, eliminateslosses in quality and quantity, offers a comparatively shortinstallation and uninstallation time, has an opening-to-production rate of 100%, and enables transportation inboth directions when required.In the light of the results of this study, the following

recommendations should be taken into consideration inorder to ensure that the performance of timber hauloperations is a more effective and productive way.For the operation of a cable system in the forest land,

there must be an adequate quantity of wood raw materialsin the haul area. In the area where timber haul is to becarried out, the forest cable systems should be brought tothe area and installed after production operations arecompleted, and then the haul operation should beperformed. The mounting of skylines should not be madebefore completion of production operations.The cable system operators must definitely be perma-

nently employed workers. This point is important in orderto ensure productive working and the careful handling andmaintenance of cable systems by the operators. For moreefficient operation of Koller K300 cable systems, aminimum of two workers should be employed at theloading stations. This would enable the tying of hook tothe load in a shorter period of time, thereby minimizingany losses of time.The studies required to be carried out in the production

area prior to the installation of cable systems for mountingpurposes should be realized by experts. Persons notspecialized in cable system operations should not beemployed for this purpose as cable systems are expensivepieces of equipment and they cannot always be immedi-ately repaired on site.In order to prevent decrease in their efficiency and to

reduce fuel consumption, the maintenance of machinerymust be performed according to technical specification andin a timely manner. An adequate number of spare partsshould be maintained in order to prevent any loss of time incase of urgent maintenance-repair works.

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