Aht Rubber Tracked Crawlers 2nv3s

Rubber tracked mini-skidders The Jonsereds Iron Horse (Swedish Järn Hästen) was the first commercially available rubber tracked mini-skidder (crawler) to appear in Scandinavian forest operations in the early 1980ies. It was developed from smaller all terrain crawlers originally designed for hunting to transport moose and other large game over long distances. The first model was equipped with a 5 HP (3.7 kw) Honda engine. Current models manufactured by Lennartsfors are equipped with 5.5 HP (4.0kw) and 9HP(6.6 kw) and 14 HP (10 kw)engines and a wide range of accessories including manual or hydraulic winches with 1000 kg pulling capacity and even a telescopic loading crane with 200 cm reach for the 9 and 13 HP model. Depending on accessories the cost of the iron horse range between 14000 (9HP) to 20000 $US (13 HP) models. Smaller models are not recommended for forestry operations due to limited winch and pulling power. Load capacity of the iron horse reaches 1-1.2 m2 or about 1000 kg at least in downhill or flat terrain extraction. Maximum speed of the Iron Horse is 4 to 6 km /hr. Its track system is designed with different size drive and wheels and specially manufactured rubber tracks. The Iron horse can be operated by one person who walked in front of the machine and controls it with th esteeming handle. Moving the steering handle sidewise will simply change direction. A break is located in the handle as well as an emergency stop.

Fig 1: The 9 HP Iron Horse with hydraulic winch, sidewise loading boom and log trailer

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Fig 2: The 9 HP Iron Horse with telescopic crane (2 m reach) Besides the Iron Horse 3 more comparable models were developed over the last 2 decades: The Myrebak Oxen is equipped with either 11 HP (8.1kw), 13 HP (9.6 kw) or 16 HP (11.8 kw) engines with winch and loading arm. Its track system is using 2 pairs of 3 standard same sized rubber tire wheels which are covered with double rubber belts connected with U-profile steel bars. Load capacity is 1000 kg. Width of the machine is 1115 mm. Driving speed corresponds to walking speed is 4 to 5 km /hr. The ex works price of the machine is about 12000 $US without accessories.

Fig 3: The Myreback Gustafsson-Oxen mini skidder with loading boom and log trailer www.myreback.com

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The Kapsen Iron Horse is a 13 HP (10kw) powered rubber tracked machine developed recently for the Czeck market. Its hydraulic power system allows gradual control of travelling speed of up to 6 km/hr via the tow bar.It has a hydraulic winch and a log loading boom. It can also be equipped with a hydraulic clamp bank for smaller sized material (e.g bamboo) and a log trailer. Loading capacity is 1.5 m3 and its pulling capacity is about 1000 kg, the width of the machine is 120 cm , the width of rubber tracks is 40 cm. Its price ex works is about 15000 $US

Fig 5: The Kapsen Iron horse www.lesni-technika.cz / [email protected] Blatna Forest horse MK 18 The forest horse is developed for the Czeck market. It is equipped with a Kohler Command 18 HP petrol engine. Its loading capacity is 1-1,2 m3 or 800-1000 kg. Its winch pulling capacity is with 1500 kg the highest in comparison to the above models. It has a winch with a cable capacity of 45 m with 6,3 mm or 35 m length with a .8mm steel cable. The winch can be remote controlled, which is a considerable safety aspect during log extraction to the point of loading on the mini crawler. Its travelling speed is 4-6 km/hr. Machine width is 120 cm with 40 cm wide rubber tracks. The ex work price of the machine is ? $US.

Fig 6: Blatna Forest Horse MK 18 www.engineeringblatna 3

Related machinery: It is worthwhile to mention that there are currently three related Swiss models of winches in the market the (1) the Alther Raup trac with a 48 HP Kubota engine and a 4 ton winch(www.martin-alther.ch) and the Wicki Forst Raupe with a 55HP Lombardini diesel engine and a Adler 4 t winch with 150 m rope capacity .(www.wickiforst.ch) Aggeler Forstraupe with a 33 HP (25 KW) engine and a 4 ton winch, rope capacity 100 m (www. Aggeler.ch).These machines fall however in a considerably higher cost range of over 30000 $US and are thus not considered further in this context.

Fig 7: Alther Raup trac rubber tracked forwarding winch www.martin-alther.ch

Rubber tracked mini crawlers manufactured locally from rice harvesting machines In South East Asia there is a wide range of rubber tracked rice harvesting machines available, which offer the possibility to convert such machines in to small forestry forwarding machines. In 2011 under RECOFTC’s Livelihoods and Markets program a Yanmar 9 HP ?? rice thrasher (see picture below) was converted into a mini-skidder. This was achieved by turning the engine on the chassis and moving the break controls forward onto a 1 m steering arm and the gear system in reverse position. The crawler has a groundspeed of max.3 to 4 km /hr. It loading capacity is around 600 kg on flat terrain without any log trailer . It has a special loading device with spiked vertical claws in order to prevent smooth bamboo from sliding off the clamp bank. The machine even offers a drive shaft for attachment of a spill winch and the possibility to increase speed through change of the gear ratio in the transmission belts. Similar machinery can be built for around 3000 $US, where about 1200 to 1500 $US are for used rice thresher base machines and about 600 to 800 $US for conversion work

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Fig 8: The Yanmar 9HP rice thresher before conversion, note the white handle for forward movement

Fig 9: Kubota Rice harvester (3 cylinder diesel 18 HP) rubber tracked base

www.plunkettorchards.com.au

Fig 10: Yanmar bamboo crawler with engine in reverse position and with clamping device for bamboo poles

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Productivity and efficiency in extraction of timber (1) Nordfjell (1994) carried out a thinning study in Sweden with the Jonsereds Iron Horse in a 26 year old spruce forest on flat terrain. Extraction distance was 80 m to strip roads for loading to crapple loading forwarders. Mean volume for thinned trees was 0.06 m3. Pile size at road side was 0.68 m3. Harvesting efficiency was 0.71 h/m3/pers or 5.7 m3/pers/day.based on a 8 hr shift. The use of the Iron horse showed particularly advantages in pulling down trees which got entangled in neighboring crowns during felling. The performance was similar to motor manual thinning with manually dragging the logs to strip roads over average distance of 41 m. It becomes obvious from this study that the advantage of the system starts in situations where larger extraction distances (100 m ++) have to be covered. (2) In a study by UK Forestry Commission (2001) extraction with the iron horse was studied on broadleaf forests (oak /ash/ birch) on 30 % slope over extraction distance of about 100 m Table 1: Output of skidding (winching to machine) and forwarding to roadside Load size (m3) 0.20 0.30 0.40 0.50 0.60 0.70 0.80 Skidding output 1.00 1.21 1.35 1.39 1.47 (m3/person/hr) Forwarding (good access) 1.75 1.86 2.03 2.30 (m3/person/hr over 100 m) Forwarding (poor access) 1.49 1.58 1.68 1.90 (m3/person/hr over 100 m) Work time included 17 % for rest 16% other work. Felling a delimbing was not included in the time study. (3) In a further study by UK Forestry Commission (1996) the Oxen Miniskidder was tested in young mixed broadleaved forests Productivity data of this trial was as follows Table 2: Productivity data for Myreback Oxen in 1 man forwarding operations Site I II Slope Moderately steep Steep Mean extracted load (m3) 1.43 1.06 Average piece size (m3) 0.027 0.028 Extraction distance (m) 168 55 Output (m3 /hr ) 1.7 1.35(manual) -1.5 (wire loading ) 3 Daily output (m /day/pers ) 13.5 11 -12 Work time included 25% for rest and 20 % for other work. Felling a de-limbing was not included in the time study. (4) Gallis (2004) carried out a comparative study in mountainous terrain in Greece between the Jonsereds Iron horse with a 2 men team and a team of 2 men and 6 pack horses/mules in the extraction of small timber( fuel wood size 0,01-0,02 m3). The observed 20 extraction cycles for the iron horse had an average distance of. 320 m (270 to 360 m) on sloping terrain (15 to 20 %). The average performance 6

of the team was 29 minutes corresponding to 3.0 m3/hr for the average distance with an average output of 1.5 m3/pers/hr. The figures presented here are conversion from the (stacked) cord cubicmeter 1.2 x1.0 x 1.0 m used in the study by a factor of 0.6. Felling and de-limbing was not included in the time study; it also did not include rest or other time categories. On a daily basis (8 hrs) this may correspond to about 7 m3/person/day, assuming at least 30 % for rest and other time categories. Due to the lower costs of horses and labour costs the mini skidder extraction had 26 % higher costs. (5) Halbrook (2005) studied the Iron Horse with a two man team in fuel load reduction in Idaho in comparison with tractor and ATV extraction. The analysis was divided into two segments, (1) a felling/de-limbing/bucking phase, and a skidding phase. During this study 45 skidding turns were recorded, totaling 130 logs with a total volume of 27 m3. During the felling/de-limbing/bucking phase, the mean total cycle time (including delays) was 8.99 minutes. On average, 3.31 logs were produced ranging from 3 to 8m in length with an average of 5.1 m. The average log contained 0.21m3 with a butt end diameter of 25 cm. During this study, phase 1 (felling/limbing//bucking) production averaged 15.4 logs (+/- 2 logs) per hour with a total volume of 3.2m3 /hr (+/- 0.42m3)Delays ed for 43% of the total cycle time of which 9% were mechanical, 38% operational and 53% personal. Clearing trails, slashing brush, and cutting small (< 5 cm) trees ed for 92% of all operational delays. Analysis results suggest that piece volume ratio is the only statistically significant predictive variable for the observed de-limbing, and bucking phase. Phase two of the Iron Horse study involved the forwarding of logs to a landing. During this phase, the mean total cycle time (including delays) was 13.68 minutes. On average, 2.89 logs (4.7m in length) were skidded per cycle. The average load volume was 0.6m 3. Delays attributed 28% to the total cycle time which included mechanical (0.1%), operational (28.8%), and personal (71.1%). Personal delays were operator rest periods, which reflect the intensive manual labor component of the Iron Horse system. The predictive model for the Iron Horse skidding phase suggests that the number of logs and the overall load volume have a significant influence on the delay free cycle time. Forwarding production averaged 12.7 logs/hr (+/- 0.7 logs/hr) with a total volume of 2.54m 3 (+/- 0.14m 3) per hour or about 10 m3/pers/day. Fixed, operating, and labor costs were calculated for the Iron Horse system on a per scheduled machine hour(SMH) basis. The hourly operating costs for the Iron Horse mini-skidder were calculated at $26/hr. Included in the operating cost was a labor component of $21/hr ($15/hr + 40% benefits). Labour comprised 81% of the overall operating cost. Utilizing the average total cycle times (including delays) for the felling and skidding phases, the costs per cubic meter ranged from $16 to $19 with an average of$17.5. The production rates obtained during this study suggest that a single phase1 worker could fell, limb, winch and buck enough material to keep one Iron Horse operator busy skidding.

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Productivity and efficiency in mini-skidder extraction of bamboo RECOFTC carried out intensive harvesting trials on bamboo (Bambusa membranaceus, local name Mai sang) during the dry season 2013/14 in Bokeo province Northern Laos (Salakka, 2014). These trials aimed at clarifying extraction costs for bamboo poles with and without branches to roadside where mobile chipping into biomass chips followed. The trials aimed at the feasibility of biomass fuel chip supply for power generation. Besides the JONSEREDS Iron horse and the locally crawler converted form a Yanmar rice harvester hand sulkies , motor winches and tractors were used in the comparative trials, being the first of its kind on record . Felling and skidding with Iron horse winch The Iron horse was used also for skidding (winching) trials in combination with chainsaw felling in both thinning culms leaving U shaped remnant culms and clear felling of clumps. The Iron horse winch proofed far more powerful in comparison with tested hand and portable winches. Forces needed for entangling of bamboo clumps were so strong that despite the heavy weight of this machine, an additional anchoring point was still required in order to keep the iron horse in place Skidding distances were between 15 and-25 m, dependent on the winch placement.

Fig 11: Iron Horse power winch used to extract bundles of entangled bamboo The work team consisted of one chainsaw operator for felling and one operator for the mini crawler. The average cycle time was 37.5 minutes and the average extraction volume was 159 kilograms (bundle of 5 to 10 culms) . The overall productivity reached the level of 0.128 t/h/person. Chainsaw productivity was increased from 0.665 to 1.021 t/h when delimbing was omitted.. Preparatory work required 21.46% of total time of winch operator. These numbers illustrates very well how time consuming this process was and therefore this approach is too inefficient and should not be performed anymore.

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Table 3 : Element times within the iron horse bamboo skidding cycle U-shape Element Preparatory work Clearing area around the clump Removing undesired material Chainsaw cutting Bundling the culms Extraction with winch Delimbing Stacking Delays Waiting Overall time, min

6.6 0.3 8.2 5.0 2.9 3.3 28.9 8.1 2.8 66.1

Clear cutting Chainsaw Winch 3.4 8.0 2.1 0.0 5.6 0.0 3.8 0.0 2.1 3.0 2.5 10.6 0.0 0.0 3.5 12.6 2.3 0.8 12.3 2.4 37.5 37.5

Table 4.: Productivity during the iron horse bamboo skidding trial Productivities Chainsaw Winch Delimbing, chainsaw Stacking

U-shape 0.665 1.428 0.306 1.099

Clear cutting 1.021 1.526 Omitted 0.592

t/h t/h t/h t/h

Noticeable stacking productivity decreased dramatically when delimbing is not performed due to heavy entangling within the extracted bundle. Stacking required 33.73% of total time of the winch operator and 9.38% of the chainsaw operator.

Forwarding with Iron Horse mini-skidder Iron horse forwarding productivities was measured over an extraction distance of 350 m. Results with different raw material categories are presented in Table .

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Fig 12 : Forwarding Bamboo culms with branches by Iron Horse Table 5: Iron horse productivity and average load and cycle times with different culm categories

Dead culms Below 5 cm delimbed Over 5 cm delimbed Below 5 cm whole culm Over 5 cm whole culm

Productivity, t/h 0.472 0.731 0.783 0.463 0.532

Average load, kg 366 556 710 343 549

Average cycle time, min 46.6 45.6 54.5 44.5 61.9

Table 6: Time elements in Iron horse forwarding of bamboo over 350 m

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Element Trip without the load Loading Tie-up the belts Trip with the load Opening the belts Unloading Delays Overall time, min

Dead 7.2 14.7 5.7 9.0 2.4 7.7 0.0 46.6

< 5 cm > 5 cm < 5 cm delimbed delimbed whole tree 7.7 6.5 6.2 13.0 13.9 15.0 6.7 6.9 3.9 8.3 10.3 5.7 2.1 3.7 0.9 7.8 10.7 8.9 0.0 2.5 3.9 45.6 54.5 44.5

> 5 cm whole tree 5.9 21.6 4.5 9.4 1.5 19.1 0.0 61.9

Table 6 shows that loading and unloading has required 40 minutes of total cycle time or in the other word 65% of total time due to a heavy weight of culms and large quantity of entangled branches. Forwarding with locally manufactured mini skidder The locally manufactured mini skidder was used in the same way as the Iron horse for forwarding its productivity varied from 0.241 t/h (dead) to 0.401 t/h (over 5 cm whole culm). The average cycle time of all categories is 63.9 minutes (compare to Jonsered iron horse ~45 min), which is mainly due to its 50 % lower travelling speed as compared to the Iron horse, an issue which should be addressed by changing its gear ratio .

. Fig 13: Forwarding delimbed bamboo culms by local mini-skidder

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Table 7: Productivity of local mini-skidder, average load and cycle times with different culm categories

Dead Below 5 cm delimbed Over 5 cm delimbed Below 5 cm whole culm Over 5 cm whole culm

Productivity, t/h 0.241 0.362 0.348 0.356 0.401

Average load, kg 226 340 437 385 443

Average cycle time, min 56.4 56.4 75.3 65.0 66.3

Table 8: Time elements between different elements of forwarding with local mini- skidder

Element Trip without the load Loading Tie-up the load with belts Trip with the load Opening the belts Unloading Re-loading during the trip Delays Overall time, min

Dead 12.5 4.9 4.9 15.2 1.1 2.9 14.9 0.0 56.4

< 5 cm > 5 cm < 5 cm delimbed delimbed whole tree 12.5 12.5 12.6 7.8 8.2 16.8 6.7 7.4 12.4 12.4 13.8 10.7 1.9 2.4 5.9 6.0 8.2 6.6 9.2 22.9 0.0 0.0 0.0 0.0 56.5 75.4 65.0

> 5 cm whole tree 12.6 11.0 8.5 13.6 2.8 11.6 6.0 0.0 66.1

Both mini-skidders performed well in comparison to the current purely manual operation where extraction rates per day only reach about 300 kg/person over maximum distances of 100 to 150 m. Also in the felling operation the iron horse winch proofed to be extremely efficient making the entangling of individual culms no longer necessary but allowing the extraction of partly cut clumps in bundles of 5 to 10 culms. Further improvements on the local mini-skidder in of the gear ratio/travel speed and the clamping device will increase its performance by at least 30 %.

Conclusions: Rubber tracked mini-crawlers are offer interesting technical alternatives to extract medium sized timber, fuel or pulpwood and bamboo particularly if extraction distances are over 200 m or in uphill extraction situations. At shorter distances manual extraction or the use of sulkies and animals will in most cases be economically more viable. Their main disadvantage is their relatively high machine costs. Locally

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manufactured systems be converting rice harvesting machinery may offer opportunities for greater economical viability of such machine types

Literature Forestry commission UK (2001) The iron horse. Outdoor workshop Information Note. ODW 8.02, 3 p. Forestry commission UK (2001) Extraction by the iron horse in broadleaved woodland. Report 1/93p. Forestry commission UK (1996) Small scale mechanized extraction: Case studies (Oxen) Report 2/97. Gallis, Ch.(2004)Comparative cost estimation for forwarding small-sized beech wood with horses and mini-skidder in Northern Greece. Forest Products Journal 54 (11): 84-90 Halbrook J.M.(2005)Productivity and Cost Analysis of Three Small-Scale Harvest Systems for Fuel Reduction Within the Wildland Urban Intermix of North Central Idaho. MSc-Thesis. College of Graduate Studies. University of Idaho Holmsen. S.D. (1988) Selectively logging dry belt douglas fir with the Iron horse Mini Skidder Forest Engineering Research Institute of Canada (FERIC), Vancouver. Field note Silviculture -9, 2p. Lindroos,O.(2004). Minilunnare / miniskotare FÖR-programmet Del. 8 Small scale forestry equipment http://www-ssko.slu.se/~diwa/FOR.htm Nordfjell, T. (1992) Repair and maintenance costs for mini skidders. Small scale forestry 2: 15-18 Nordfjell, T.(1994) Comparative time study of thinning with mini-forwarder (Jonsereds Iron horse).Swedish University of Agricultural Sciences Dept of Operational Efficiency Res.Note 267 .79 p. Salakka J.( 2014) Identifying Appropriate Small Scale Harvesting Technologies for Commercial Scale Bamboo Fuel Chip Production in Lao PDR, Karelia University Applied Sciences Degree Program in Forestry 64 p

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Appendix:

1. Machine Cost Calculation Manufacturer:

Model:

HP:

Purchase price :

$ _________________

Total price of transportation to site:

$ _________________

Total:

$ _________________

(P)

INITIAL INVESTMENT

(S)

Salvage Value (__% of P)

(N)

Estimated Life: ____ years

(SH)

Scheduled operating time: ___ hrs/yr

(U)

Utilization: ___ %

(H)

Productive time ____ hrs/yr

(AVI)

Average value of yearly investment AVI = [((P-S)(N+1))/2N]+S

$_______ $_______

$_______/yr

I. Fixed Cost: Depreciation= (P-S)/N

$_______/yr

Interest (__ %), Insurance (__ %), Taxes (__ %) Total __ % x ($__/yr)

$_______/yr

(1) Fixed cost per year

$_______

(2) Fixed cost per H (1÷H)

$_______

II. Operating Cost: (based on productive time) Maintenance and repair (__% x ((P-S)/(N x H))

$_______

Fuel (____ L x $____/L)

$_______

Oil & lubricants

$_______

Tires (1.15 x (tire cost)/tire life in hrs.)

$_______

(3) Operating Cost per H

$_______

III. Machine Cost per H (without labor) (2+3)

$_______

IV. Labor Cost ($___/hr ÷U)

$_______

V. Machine Cost per productive hr. with labor (III + IV)

$_______

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Suppliers (1) Jonsered Power Products S- 433 81 Jonsered Tel: 031-94 90 00, Fax: 031-94 91 10 www.jonsered.se (2) Myreback Maskin Box 12 S- 667 21 Forshaga Tel: 054-87 23 10 Fax: 054-87 42 82 [email protected]

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