Harvesting mixed tropical timber for paper

Torsten Frisk

TORSTEN FRISK is an FAO logging specialist with extensive experience in Latin America

Pulpapel S.A. is located just outside of Cali, Colombia and is a subsidiary of the country's fifth largest company, Cartón de Colombia. In addition to its importance to the country as a manufacturer of paper and paperboard for the packaging of agricultural products, Cartón is significant in the world of pulp and paper as a pioneer in the use of tropical hardwoods for making pulp. It is one of the few companies in the world that is doing this on a regular commercial basis. Its products consist of liner board, corrugating medium and sack paper, all made from sulphate pulp. In most of its paper and board grades about 30 percent long fiber is added to the furnish, coming from either pulp or wastepaper. The long-fibre virgin pulp costs approximately US$500/t in Cali (the rate of exchange used here is 1 dollar = 32 pesos).

As the actual demand is growing at a compound interest rate of 7-9 percent, production will have to be doubled in a period of 10 years.

To avoid dependency on foreign pulp, a reforestation programme has been implemented which will yield in the future a sufficient quantity of long fibre pulp. It is estimated that by 1983 the needs will be around 60000 t/year.

The reforestation programme to cover this figure is 1750 ha/year. The principal species are Cupressus lusitanica, Pinus oocarpa, Pinus patula and Pinus kesiya The plantation density is 1600 trees/ha. One thinning is planned at 6-8 years. Since 1974800 ha/year of eucalypts are being planted and three nurseries attend to the planting needs with a total production of 11 million plants per year. As a promotion measure, plants are sold at 0.5 peso per plant, which is half the production cost.

In Carton's operation the first stage - logging - is obviously very important and it is the role of Pulpapel to carry this out.

This article is a forest engineer's technical report of how one company goes about harvesting the jungle for pulp wood.

The supply delivered by Pulpapel S.A. is approximately 280000 t (400000 m³) debarked wood per year. Thirty percent of this volume comes from the concession of Bajo Calima and the rest from 300 suppliers grouped in three categories:

· Contractors or peasant communities with permits from the State to harvest forest areas.
· Private landowners who clear the forests for agriculture.
· Private landowners who clear the forest for reforestation purposes.

The duration of the round trip over the average distance of 165 km including loading is 4-5 days. The water transport is in relation to the tides, which can fluctuate up to 6 m one to three times per year.

The dimensions and characteristics of the wood supplied to the industry is as follows:

The wood is debarked. The maximum diameter is 40 cm, the minimum 10 cm. Logs over 40 cm are split in the forest. The length is 1.50 m minimum 1.20 and maximum 2.00 m. Latex and silica cause processing problems, so species with a high content are avoided. High density species are also avoided. Palm trees are not harvested. Logs with a high proportion of rot and with a middle curvature of over 35 cm are left in the forest.

The Company uses the stere a volume measure, but the dimensions are 1 m × 1 m × 1.50 m long.

The conversion factor of volume/weight used is:

1 m³ solid, debarked, air dry one month = 0.7 t.

The conversion factor weight wood/weight pulp is:

3 t wood = 1 t pulp; or 4,3 m³ wood = 1 t pulp.

The Bajo Calima concession

The concession of Bajo Calima comes under the jurisdiction of the Municipality of Buenaventura, Department Del Valle. It covers an extension of approximately 54000 ha, of which 26000 ha are considered commercial. The concession rights cover a period of 30 years, according to the contract signed between the Company and the Instituto de Recursos Naturales Renovables (INDERENA); an excerpt from the contract can be found at the end of this article.

Here are the main points of the contract:

· Before the concession was made official, the Company had to prepare a Management Plan for approval by INDERENA.

· Some areas were reserved for colonization and small landholders.

· The authorized yearly extraction was fixed at 84000 t/year (120000 m³).

· A reforestation rate that at the end of the period would generate an equal or superior volume than that extracted was indicated. Reforestation could be done in another area of tropical forest under certain circumstances.

· Two payments were fixed per cubic metre extracted, to be paid to INDERENA. The first covers the national participation and the second is for control and forest conservation services provided by INDERENA. The national participation is 5 percent of the value of the harvested timber. This value is 70 p/m³ ($2.19/m³) when the wood is destined for pulp. The national participation is therefore 3.5 p/m³ ($0.11/m³). Control and forest services amount to 10 p/m³ ($0.31/m³).

The forest administration agrees on the forest concession system, as it permits them to exercise more control over harvesting. This is also convenient for the Company because it guarantees part of the wood supply, and depending on the period of the concession also permits larger investments in infrastructure. A short concession will favour the take-and-leave attitude, with no infrastructure.

The concession is situated in a very favourable location as its boundary runs along the Cali-Buenaventura highway. The distance from the entrance to the concession to Cali is 102 km, and to Pulpapel S.A., 120 km; from the entrance to the nearest logging tract is 14 km. This location, plus the excellent interior road network built by the Company, permits a continuous flow of wood from the concession to the industry.

The distance from Cali to Buenaventura is 126 km. The road is paved, in good condition, but with many curves; the topography is difficult and it crosses a mountain ridge. The side slopes have not been stabilized and after heavy rain landslides are common. From Cali the road zig-zags up to 2080 m over a distance of 18 km. These factors determine that a normal vehicle takes 2.5 h and a truck 5 h to reach the concession.

The topography of the concession corresponds to low hills with slopes ranging from 0 to 30 percent. The soil contains a high proportion of clay and therefore has bad drainage. Organic material is low. The annual rainfall ranges from 6500 to 7500 mm. The concession is at a height of 150-200 m above sea level.

By law, 200 m on each side of the roads, and 500 m at riverside are open to colonization.

This has originated the establishment of small farmers who practice shifting cultivation, although only to a small extent because the soil fertility is extremely low. This last fact has held back massive colonization in the concession. A subsistence activity consists in cutting the regrowth of the forest after 2-3 years and using the wood for construction poles. This practice certainly leads to the impoverishment of the forests, but it does allow small amounts of cash flow. The poles are sold at the roadside, at 5 or 7 pesos each, according to size. The system could be improved by choosing the most appropriate species and following a simple management plan. Pit sawing is also practiced with the larger trees.

Forest characteristics: The forest is mixed tropical, homogeneous-heterogeneous, and composed of 180 species. Out of this number, 160 species are used for pulp. The average total volume per ha is 159 m³ with bark. The utilized volume is 105 m³/ha with bark. The average volume per tree is 0.33 m³. After harvesting the forest, the area can be reforested without great difficulty. The average diameter at breast height (DBH) is 30 cm with bark.

Infrastructure: thanks to the long duration of the concession - 30 years - there are good prospects of building up a permanent infrastructure.

Roads: The roadnet is well distributed and of good quality, allowing traffic on a year-round basis, even with smaller vehicles with which one can reach all the logging sites.

Road construction and maintenance is done by two different contractors: Calderón y Cía (Road construction) and Agustín Barona (Road maintenance and transport of wood).

Roads actually in service total 76 km, of which 48 km are main roads and 28 km secondary.

As an example for road density calculation, in one unit of 750 ha there are 5 km of roads. The density would then be:

The road specifications are as follows:

Specification	Main road	Secondary road
Right-of-way	8-9 m	6
Width of the road	6 m	4
Maximum grade	6.5%	8
Minimum radius	50 m	40
Lay-by	150 m	150
Thickness of gravel (m)	0.20-0.60 m	0.20
Base	Corduroy	Corduroy

The roads are laid out on the ridges, avoiding the side slopes. This position improves lateral drainage and keeps earth movement to a minimum. Places where bridges or big culverts would have to be placed are avoided. The layout of the roads is done by the Company.

Planning and construction of the road network is carried out in the following stages:

· Exploration: It consists in determining if the volume of wood justifies the construction of a road. An estimate of the construction cost is made. At this stage there is close collaboration between the topographer and the forester.

· Route selection: According to the topography, situation of the forest and existing road network.

· Preliminary layout: With compass and Abney level. The distance is estimated.

· Definite layout: With compass, measuring-tape and Abney level. Calculations of earth movement are made.

· Construction: The construction is done in three stages:

1. Clearing with buldozer.

2. Earth movement with Caterpillar D4, 75hp, or Fiat C100, 80hp. Heavier equipment is not recommended as the bearing capacity of the soil is very low. On the other hand, earth movement is kept to a minimum. In both cases the bulldozers are provided with 34-in-wide tracks. In cases where the road has to be laid out on mid-slope, the width is cut into the slope.

3. Sub-base and base. The sub-base is formed by two layers of logs. The first one is placed lengthwise and the second crosswise to the axle of the road. The corduroy is necessary due to the very low bearing capacity of the soil, which lies around 0.2 kg/cm². The corduroy permits a better distribution of the pressure on the soil and prevents the gravel sinking. The average diameter of the logs is 10 cm.

On one kilometer of main road the volume of wood used for the corduroy is 750 m³ with a space factor of 0.82 (0.0078 × 60000 × 0.8) = 750 m³. If we consider the road density of 6.7 m/ha, the volume of wood used for the corduroy amounts to 5 m³/ha. A 20 cm-layer of gravel is distributed over the corduroy. This layer reaches 60 cm after successive gravellings. The gravel is spread either with a motor-grader or by hand. The average distance of gravel transport is 18 km. The dump trucks used are mainly Dodge D-600 with a 6 t capacity. Transport of gravel is done by contractors who are subsidized by the Company for the purchase of trucks. The trucks are loaded by a crawler shovel with a capacity of 1 m³.

Equipment specifications and costs

IWATE FUJI Yarder

Approximate price	US$30000
Model	Y-28 EG
No. of drums	3
Transmission	Sliding gear type with 4 forward and 4 reverse speeds
Drum brake	Expanding shoe-type, hydraulic
Drum capacity	1350 m 8 mm wire rope 850 m 10 mm wire rope 590 m 12 mm wire rope
Engine	Mitsui-Deutz F3L - 912, diesel, 44 hp at 2500 r.p.m. 4 cylinders
Weight	1775 kg

BOMBARDIER Muskeg Tractor - JIMMY Skidder

Approximate price	US$30000
Ground clearance	35 cm
Shipping weight	4800 kg
Maximum speed	20 km/h
Turning radius	3.6 m
Ground pressure	2.19 p.s.i. (0.15 kg/cm³)
Gradeability	Sidehill 25% Uphill/downhill 60%
Engine	Make, Detroit Diesel model GM 4.53, 4 cylinders, 130hp.
Winch	Germatic model 9, with 10000 lbs line pull, 157 ft 1/2" cable drum capacity
Tracks	Rubber belts with steel crosslinks, 70 cm wide, 2,18 m long
Payload	5 t

BOMBARDIER B-15 Transporter

Approximate price	US$60000
Ground clearance	48 cm
Shipping weight	17000 kg
Maximum speed	24 kmh
Turning radius	3.0 m
Ground pressure	1.95 p.s.i. 10.14 kg/cm² at 0 penetration
Gradeability	Sidehill 65%; Uphill/downhill 75%
Engine	G.M. 6V-53 diesel, 195 hp
Tracks	Rubber belts with steel crosslinks, 1.0 m wide
Payload	10 t

TABLE 1. Output for the preparation of logs in both cable and manual extraction

Operation	Cable extraction	Manual extraction
Felling	Yes	yes
Debranching	yes	yes
Bunching	yes	yes
Debarking	yes	yes
Splitting	yes - diameters over 40 cm	yes - idem
Piling	cable line	roadside
Output	3.2 Company steres 1 man/day	1.0 idem
	3.1 m³ solid without bark2 man/day	1.0 idem

¹ 1 m × 1 m × 1.50 piled volume.
² Using a space factor of 0.65.

The existence of gravel and the short transport distances are perhaps the most important factors in the opening up of tropical forests, and gives this particular concession a great advantage. Wooden bridges are built on piles driven into the ground with a falling hammer. The wood used comes from mangrove forest and has bearing and rot-resistance. The 28 cm-diameter culverts are made of cement and are usually 8 m long. The average is 16 culverts per km.

Where landslides occur, lateral piles are placed to retain a new fill.

Output of road construction: Road construction advances 1 km per month on a 10 hour/day effective working time. The average output of the 75 hp bulldozer is 16 m³/h. Six metres of corduroy are laid out by one man/day, working 8 effective hours per day.

Costs of road construction:

Main road: 750000 p/km ($23500/km)
Secondary road: 580000 p/km ($18000/km)
This means more or less 4480 p/ha ($140/ha), or 43 p/m³ (US$1.34/m³).

Some partial costs of road construction are as follows:

Clearing	18.50 p/m ($0.58/m)
Earth moving in cut	18.50 p/m³ ($0.58/m³)
Earth moving in filling	9.25 p/m³ ($0.29/m³)
Corduroy	39.50 p/m ($1.23/m)
Transport of gravel 18 km	131.00 p/m³ ($4.00/m³)
Manual spreading of gravel	4.60 p/m ($0.14/m)
Spreading of gravel with motorgrader	16.50p/m ($0.51/m)
Formation with motorgrader	11.60 p/m ($0.36/m)
Culverts	167.00 p/m ($5.22/m)
Side ditches	5.80 p/m ($0.18/m)
Bridge pilling, labour	800.00 p/m ($25.00/m)
Mango wood	1280.00 p/m ($40.00/m)

Road maintenance costs per month amount to 190000 p ($6000), or 32000 p/km/year ($1000/km/year). This value is equal to the normal 5 percent of the construction cost. The maintenance cost per cubic metre would amount to $0.06.

Camps: There are three camps in the concession, one for the Company personnel and the other two belong to the contractors. These have maintenance workshops for heavy equipment. Electricity is produced in each case by diesel generating sets.

Harvesting

Two contractors are in charge of harvesting operations in the concession of Bajo Calima: Aprovechamientos Forestales Ltda. and Maderas Tropicales. Each contractor supplies 3500 t of wood per month (42000 t/year). Harvesting operations continue through all working days of the year, i.e. 240 days. Work continues during rainy spells and this is necessary because of the heavy rainfall. The effective working time per day is 6 hours.

Figure 1. - A logging unit, showing parallel lines set perpendicularly to the road.

The different operations are well organized and it can seen that there is a lot of experience in working with cable systems. The foiling operations can be distinguished:

· Preparation of logs: Felling with axe. Branching with axe. Bucking with chainsaw. Debarking with machete or axe. Splitting with wedge and hammer.

· Skidding: Manual. Cable systems.

· Transport: With dump or platform trucks.

Appraisal of resources: Before the harvesting of the forest, and as a prerequisite stated by INDERENA, an inventory has to be carried out in the unit that will be harvested during the coming two years. The design of the inventory has been established by INDERENA.

The inventory is carried out on lines, which are separated by 50 m and projected from the road laid out by the topographer (Figure 1).

The unit is designed so that the road passes more or less through its centre. Of the total number of lines which are stratified in the unit, 10 percent are chosen at random. A base camp is located at a strategic point in the unit and the inventory crews are formed. Each crew is composed of 4 people. Every 50 m on the chosen lines a reference stake is placed, corresponding to the number of the site. Up to 20 stakes are placed, to a maximum penetration of 1000 m.

Once the line has been staked the crew returns to the starting point and begins to advance on the line, measuring diameters and commercial heights on a strip of 5 m toward each side of the inventory line. The d.b.h. is measured with a caliper, averaging two measurements. The commercial height is estimated. The advance is approximately 1 km per day.

For the calculation of volume a local volume table designed by the Company is used. The heading of the form used in the field is shown below.

PULPAPEL S.A. PRE-HARVESTING FORM Unit:		Date: Line: Azimut: Longitude: Crew: Responsable:			Line	Site	Infl.
					1 2 3	4 5	6
Tree No.	Common nome of species:		Code	Diameter m	Commercial height m			Observations
7 8			9 10 11	12 13 14	15 16 17

INDERENA revises the inventory in the field. A difference greater than ± 20 percent is not accepted. The revision is by basal area, and some commercial heights are compared with the forms of the Company.

Preparations of logs: The organization of this operation consists in giving 1400 m of road to 7 crew chiefs. This stretch, penetrating 300 m on each side of the road, has to be ready in 4 months. Each crew consists of 7 workers for cable extraction and 9 workers for manual extraction.

The chainsaw operator moves from one labourer to another crosscutting the trees. The other operations are done independently. Felling and debranching are done with a 4-pound axe. Crosscutting is done by chainsaw. One of the main reasons why the chainsaw is not used for felling is due to lack of vocational training. The average operating time of the chainsaw is 4 hours/day. The Homelite XL-925 (82 cm²) with a 65-cm blade is the most common mane and it is considered to give satisfactory results.

After crosscutting the logs are debarked with a machete or an axe. Seasons have no influence on debarking, but there are differences between species. After debarking, the logs of over 40 cm diameter are split with wedge and hammer and piled either along lines where the cable system will operate or at the roadside (see Table 1).

A worker earns 23 p/m³ ($0.72/m³) for cable extraction and 70 p/m³ ($2.19/m³) for manual extraction over an average distance of 150 m. A chainsaw operator earns 10 p/m³ ($0.31/m³) on the basis of the total production. An amount of 50 percent is legally foreseen for social laws, but the company covers an extra 10 percent for workers' benefits.

Figure 2. - Modified North Bend system.

TABLE 2. Operation time and output of the Modified North Bend system

Distance	Total time	Output	Corrected output
m	minutes	m³/hr	m³/hr
100	3.83	13.82	10.00
200	4.61	11.06	8.30
300	5.39	9.46	7.10
400	6.17	8.27	6.20
500	6.95	7.34	5.50
600	7.73	6.60	4.95
700	8.51	6.00	4.49
830	9.29	5.50	4.12
900	10.07	5.06	3.80
1000	10.85	4.70	3.52

TABLE 3. Operating time and output of the Iwate Fuji skyline system

Distance	Total time	Output	Corrected output
m	minutes	m³/hr	m³/hr
100	5.33	12.72	9.54
200	6.08	11.15	8.36
300	6.83	9.93	7.45
400	7.58	8.94	6.71
500	8.33	8.14	6.10
600	9.08	7.47	5.60
700	9.83	6.90	5.17
800	1058	6.41	4.81
900	11.33	5.98	4.49
1000	12.08	5.61	4.21

TABLE 4. Operating time and output of the Jimmy Skidder

Distance	Total time	Output	Corrected output
m	minutes	m³/hr	m³/hr
100	19.97	7.51	5.63
200	26.37	5.69	4.27
300	32.77	4.58	3.43
400	39.17	3.83	2.87
500	45.57	3.29	2.47
600	57.97	2.89	2.17
700	58.37	2.57	1.93
810	64.77	2.32	1.74
900	71.17	2.11	1.58
1000	77.57	1.93	1.45

Extraction of wood to roadside. Two methods are used for the extraction of wood to the roadside: manual extraction over an average distance of 150 m, and mechanical extraction with cable. The manual extraction was analysed in the previous paragraph as it is part of the felling and related operations for payment purposes.

Two cable systems are used: the Modified North Bend system and a skyline cable system. They are operated either separately or combined.

Modified North Bend system: This system has been used for some years by the Company and the personnel has acquired much experience. It has now become a traditional system. The main parts of the system are shown in Figure 2.

The system consists of sweeping a circle or semi-circle, and drawing the wood toward the head spar. The system can be used on flat ground or on slopes.

The logs are skidded on the ground but the Modified North Bend system permits a higher lifting effect of the logs, so the winch can be mounted in the valley to cover short distances.

The difference between the Modified North Bend system and the North Bend system is shown in Figure 3.

The Company uses various installation patterns, which are illustrated in Figure 4.

The tail spar is moved after extracting the wood in a strip describing a semi-circle or full circle. At each installation of the tail spar, 10° apart, the wood is drawn to the head spar at the roadside or in the forest, from which point the wood is transported by another installation.

When the Modified North Bend system is used combined with the skyline system, the North Bend sweeps in a semi-circle or full circle and the skyline system transports the whole or split from the head spar to the roadside.

The winch of the North Bend is produced in Columbia and is driven by a 37.5 hp Lister motor. The Company owns 20 winches.

The average load per trip is 0.68 t (0,85 m³).

Figure 3. - Difference between the North Bend (right) and the Modified North Bend (left) systems.

The average time of the individual parts of the complete operation, over a distance of 450 m, is as follows:

Empty trip	1.62 minutes
Loading	2.47 minutes
Loaded trip	1.88 minutes
Unloading	0.58 minutes
Total	6.55 minutes

The time and output formulae for a variable distance would be:

T = 3.05 + 0.0078D

T = total time, minutes
D = distance, metres
3.05 = loading and unloading time, minutes

O = output, cubic metres per hour
T = total time, minutes
0.85 = average load cubic metres (0.8 t = 1 m³)

The resolution of these formulae for distances between 100 and 1000 m give the following results:

The time study refers to effective working time. To have a better indication of actual output values that would reflect a monthly or yearly average, the output values have been multiplied by 0.75.

Figure 4. - Installation patterns.

The installation of the system on a semi-circular area will determine 18 installations of the tail spar at 10° apart. A circular area will mean 36 installations of the tail spar.

The movement and installation time of the system is 20 hours and the displacement of the tail spar is 16 hours. The total time would then be:

Semi-circular area = 20 + 288 = 308 h, 38 days
Circular area = 20 + 576 = 596 h, 74 days

The approximate operation cost per hour of the Modified North Bend including labour costs on a 1750 hour/year basis is 201 p/ha ($6.30/ha).

The total cost per cubic metre for semicircular installation up to a distance of 500 m is:

A) Installation cost per cubic metre:

Ic = installation cost, pesos/m³
Hic = hourly cost for installation, pesos/m³ (85% of operation cost)
Tzi = installation time, semi-circular area, hours
V = average volume, m³/ha
R = radius of the semi-circle

Ic = 13 p/m³ ($0.41)

B) Operation cost per m³:

Oc = operation cost, pesos/m³
Hc = hourly cost, pesos/hr
PV = proportion of volume in area
Y = output, m³/hr

Oc = 1.61 + 6.79 + 23.36
Oc = 32 p/m³ ($1.00)
Total cost = Ic + Oc = 45p/m³ ($1.41/m³)

Iwate Fuji Skyline system. This has been operated for over a year in the concession with good results. At present 2 winches are in operation. The length of the installation can be up to 1000 m, but the average is 600 m.

Two of the three drums of the winch are in use. One drum carries the endless cable and the other the main line to lift and lower the load. The endless cable is wound around the drum 7 times and pulls the carriage along the skyline (Figure 5).

The crew of a cable installation is composed of 16 men:

The winch operator earns 100 p/day ($3.12/day).
The average load is 0.9 t (1.13 m³).

Figure 5. - The Iwate Fuji system.

The average time of the individual moments of the complete operations, over a distance of 450 m, is as follows:

Empty trip	1.43 minutes
Loading	3.30 minutes
Loaded trip	1.93 minutes
Unloading	1.28 minutes
Total	7.94 minutes

The time and output formulae for a variable distance would be:

T = 4.58 + 0.0075D

T = total time, minutes
D = distance, metres
4.58 = loading and unloading time

O = output, m³/hr
T = total time, minutes
1.13 = average load, cubic metres (0.8 t = 1 m³)

The resolution of these formulae for distances between 100 and 1000 m give the following results:

The time study refers to effective working time. To have a better indication of actual output values that would reflect a monthly or yearly average, the output values have been multiplied by 0.75.

The approximate operation cost per hour of the Iwate Fuji skyline system, including labour cost on a 1750 hr/yr basis, is 369 p/hr ($11.53/hr).

Installation of the system takes approximately 32 hours. If the skyline system is installed in combination with the North Bend, working up to a distance of 500 m on a semi-circular area the n a semi-circular area the volume hauled would be:

The total cost per cubic metre for an installation of up to 600 m where the North Bend would be installed is:

A) Installation cost per cubic metre:

Ic = installation cost, pesos per cubic metre
Hic = hourly cost for installation, pesos per cubic metre (85 percent of operation cost)
V = volume that will be hauled by one installation

B) Operation cost per m³:

Oc = operating cost, pesos/m³
Hc = hour cost, pesos/hr
Y 600 = output 600 m, m³/hr

Total cost = Ic + Oc
Total cost = 68 p/m³ ($2.13/m³).

The total cost of both installations per cubic metre hauled to roadside is 113 p/m³ ($3.53/m³)

Transport. In the transport operations one can distinguish two phases: internal transport, and transport to the industry in Cali.

The transport cost from the entrance of the concession to the industry (120 km on the Cali-Buenaventura road) is 126 p/m³ ($3.90/m³).

For wood transport the Instituto de Desarrollo de los Recursos Naturales (INDERENA) issues a pass. This measure avoids to a certain extent the transport of wood from illegal operations. The pass has a duration of 10 days, and without it the wood is confiscated.

At the entrance to the concession there is a large log yard where internal transport ends. Here the wood is unloaded.

For internal transport dump trucks and platform trucks of a loading capacity of 67 t are used. If the truck has a capacity over 8 t it transports directly to the industry. Transport operations are executed on a 15 hour/day basis.

Manual loading is done by a two-man crew, who load six tons in 30 minutes. Unloading is also manual in the case of platform trucks. The loading of the dump truck takes 1 hour.

The cost of internal transport is 42 p/m³ ($1.31/m³)

Labour aspects

The minimum daily wage is 36 p/day ($1.13/day).

During the year, 240 days are considered as working days. Saturdays and Sundays are not working days, but if occasionally work is done on a Saturday then the wage is doubled.

Colombian law provides that forest workers should work on a 54 hour/week basis.

The workers come from Buenaventura and are provided with daily transport to the concession. Working hours are from 08.00 to 17.30 with a lunch break of 1 hour.

Figure 6. - Organization of extraction of wood using the Bombardier B-15 and the Jimmy Skidder.

Only 20 percent of the workers can read and write.

The personnel working in the concession is as follows:

Administrative personnel	10
Foremen	4
Mechanics	10
Choppers	8
Transport labour	16
For preparation of loge	80
For extraction	120
For roads	8
Total	256 men

If we divide the total yearly production by this number of men we have a relation of 469 m³/man-year, and 1.95 m³/man-day:

If the administrative personnel and mechanics are not considered, the production would be 2.12 m³/man-day.

Summary of harvesting and transport costs

For quick reference the individual costs have been summarized. Some partial costs have been estimated by the author, as no information was available:

	p/m³	$/m³
National participation	350	0.11
Payment to INDERENA for control	10.00	0.31
Roads	45.00	1.40
Preparation of logs	77.00	2.40
Extraction to roadside	116.00	3.53
Internal transport	42.00	1.31
Transport to industry	126.00	3.90
	419.50	12.96
Company overhead costs 15 percent	63.00	1.94
Total cost	P. 482.50	$14.90

The San Juan concession

At present only experimental harvesting operations are proceeding.

The extension of the concession is of 160000 ha, and the total volume is estimated at 15 million m³ with bark. Of this volume 3.5 million m³ is sawnwood.

The average volume per ha is 108 m³ with bark, and of this 69 m³/ha is usable for pulp. The composition of the forest is 225 usable species. Sawnwood can be extracted to an average of 28 m³/ha with bark.

The concession is situated on the banks of the San Juan River, toward the north of the present concession. It can be reached by crossing the Bajo Calima concession by car and then by boat. The production from this concession will be transported by barges, and the only manual operation will be loading of these barges.

The concession area is 14 percent alluvial and 86 percent low hills.

Experimental logging operations. A provisional camp has been constructed close to the banks of the San Juan River where the bearing capacity of the soil is very low. This area is sometimes flooded.

Poor terrain conditions have determined the introduction of experimental logging equipment produced by Bombardier Ltd., Canada. This equipment consists of 5 Jimmy Skidders and 1 Bombardier B-15 skidder (Figure 6).

The main characteristic is the wide tracks that permit more floatability. Even so, the B-15 cannot operate on bare ground because it sinks. This means that it has to operate on a corduroy road, and has determined the organization of the extraction operations.

A high protection shield welded around the Jimmy Skidder can sink up to 1.4 m into the mud. Problems have arisen with the hydraulic systems of all machines and at all times there is a mechanic present during operations.

Felling is carried out with Homelite motorsaws, Models 923 and 1050, with 25 and 30-inch bar respectively. The latter model is, however, considered to be too heavy.

Skidding operations are organized so that the Jimmy Skidders work on a strip of 500 m to the corduroy road on which the B-15 moves, and skids the logs to the riverside (Figure 6).

The output of the Jimmy Skidder after two months of operation is 17 m³/day with bark, on a 5 effective hour/day basis. This output can of course increase in the future.

The given capacity of the tractor is 5 m³, but under actual working conditions it is difficult that the average volume will be higher than 2.5 m³.

The following formulae can be used as an approximate guide, to determine the output of the Jimmy Skidder:

T = 13.57 + 0.064D

T = total time, minutes
D = distance, metres

13.57 = fixed time for loading and unloading, minutes

O = output, m³/hr
T = total time, minutes
2.5 = average load, m³
The times do not include delays.

The resolution of these formulae for distances between 100 and 1000 m give the following results:

The time study refers to effective working time. To have a better indication actual output values that would reflect a monthly or yearly average, the output values have been multiplied by 0.75.

The approximate cost per hour of the Jimmy Skidder including operator and two helpers is 398 p/hr ($12.45/hr), on a 1500 hr/years basis.

The cost per m³ over an average distance of 125 km is 42.12 p/m³ ($1.32/m³).

Legally speaking

Excerpts from the Concession Con tract INDERENA-PULPAPEL S.A.

CLAUSE I

INDERENA cedes to PULPAPEL

S.A. a Forest Concession a period of 30 years to utilize public forests located in the municipality of Buenaventura Department of Del Valle, over an extent of approximately 53804 ha, incorporated in an area of 61500 ha ...............The concessionaire accepts the following regulations:

1. concessionaire has the first option permits for utilization of the tree species in the concession area according to an established volume in the management plan.

2. The concessionaire has no rights with regard to house and land of peaceful and quiet farmers or the rights obtained by third parties in the area of the concession. The concessionaire shall not harvest forests located on a 500 m wide strip running parallel to the principal communication routes destined for use by settlers. These communication routes are...............The concessionaire can initiate legal action against whomsoever invades the land ceded to the concessionaire, and will have the support of INDERENA.

3. In no case will the concessionaire receive any indemnity from INDERENA. ...............

CLAUSE II

The concessionaire will fulfil the following special obligations:

1. Invest in the Organization of harvesting operations and plantations the yearly budget allocated for this purpose and approved by INDERENA.

2. Initiate the management plans within 3 months following the signature of this contract. It is presumed that the management plan is in execution when the concessionaire carries out felling of the allowed volume and the forest is treated according to the plan.

3. Harvest the forest according to the management plan and to the following specifications:

(a) The minimum diameter for pulpwood is 18 cm. The species allowed to be utilized are those indicated ...............

For the utilization of other species, especially those that can be used for sawnwood, a special permit from INDERENA is required.

(b) Harvest according to the management units.

(c) Perform pre-harvesting inventory with an intensity of 10 percent, including all species over 15 cm, identifying with visible numbers and marks all the species suitable for sawmilling. INDERENA will approve the inventory outline.

(d) Construct main and secondary roads permitting maximum benefit to be obtained from the forest with the minimum damage to vegetation.

(e) Maintain the harvesting techniques, with the obligation of improving methods so as to reduce waste and avoid leaving utilizable wood in the forest, or on the roads and log-yards.

(f) In those cases where INDERENA permits the utilization of sawnwood species, these species must be marked.

(g) Prepare maps of the harvested areas and of those under silvicultural treatment.

(h) Prepare in advance maps of the harvesting and silvicultural operations for the following year ...............

(i) Maintain a register of the principal harvesting operations:

1. Felling, area, volume obtained, loss of volume and reasons, output and costs;

2. Roads, (plan, design construction and costs);

3. Extraction systems, distance, extracted volume, waiting time and unproductive time, output of equipment and costs;

4. Transport systems and distance, volume, capacity of equipment and costs.

(j) In relation to the equipment used, the concessionaire is obliged to maintain information on cost-benefit relation, efficiency, production and output.

(k) If areas have to be preserved for ecological reasons, the concessionaire is not allowed to harvest these areas.

(l) During the first year of this contract the concessionaire and INDERENA will select and delimit an area of 5 percent of the total area considered to assure sample units of the natural vegetation.

4. The concessionaire should outline an internal work and security statute and comply with all existing social laws. These statutes, approved by the Ministry of Labour, should be presented to INDERENA within one year.

5. The concessionaire should build schools for the education of the forest workers, their families and children.

6. Every 6 months the concessionaire should present a written report signed by a forest engineer, giving an account of the harvesting operations completed over a period of 6 months.

7. The concessionaire may not employ foreign personnel above a proportion of 20 percent of their entire staff.

8. Demonstrate the payment of participation revenues and other rights to INDERENA.

9. The concession cannot be transferred to third parties without the authorization.

10. A forest department should be established to take charge of the management plan.

11. The concessionaire should designate a representative to INDERENA to discuss the follow up of this contract.

12. A written report on the execution of the management plan should be submitted every 6 months.

13. The concessionaire shall allow free passage on public roads, access to gas ducts, telegraphic, electric and telephone installations and irrigation canals.

14. Establish plantations with commercial species selected by the concessionaire and approved by INDERENA The expected volume of these plantations should be equal or higher than the extracted volume at the end of the 30-year period, which is estimated to be 3661745 m³. In case INDERENA and the concessionaire agree that the information to comply with the reforestation programme in the concession is insufficient, a further period of three years will be granted. This period may be extended if INDERENA considers that lack of information still exists or if the reforestation programme can be executed in another tropical forest area.

15. The concessionaire will carry out the investigations proposed in the management plan in collaboration with INDERENA.

16. The concessionaire will establish clear limits of the concession.

CLAUSE III

The concessionaire is bound to utilize the natural forest and to extract the allowed volume, paying to
INDERENA the "national participation" in relation to the market value.

The concessionaire will also pay INDERENA the established amount per cubic metre for control and management of the forest.

Payments should be effected every three months according to the volumes indicated in the pre-harvesting inventory.

CLAUSE IV

The management plan approved by INDERENA constitutes the technical basis for managing the concession.

CLAUSE V

The personnel of INDERENA can at any time supervise the management of the concession and the fulfilment of the clauses stipulated in this contract.

CLAUSE VI

The export of forest products should compromise with existing regulations.

CLAUSE VII

The concessionaire is allowed to utilize the plantation, and INDERENA will recommend to the pertinent organizations that the reforested areas are transferred in property to the concessionaire.

CLAUSE VIII

For a fuller utilization of the forest INDERENA can recommend to the concessionaire the utilization of species and products other than those agreed upon. If the concessionaire refuses to utilize these species, INDERENA can coordinate their utilization.

CLAUSE IX

With the exception of the reforested areas INDERENA can decrease the concession area in the following cases:

(a) When colonization areas cause problems to the concessionaire;

(b) When the produce of the plantations or natural forests exceed the needs of the concessionaire and when no expansion is foreseen:

(c) When the concessionaire has sound sound reasons for reducing the area in order to lower harvesting, transport or management costs due to a fuller utilization of the forest.

CLAUSE X

To guarantee the fulfilment of the present contract the concessionaire must deposit an amount of p 1838872, corresponding to p 0.50/m³.

CLAUSE XI

INDERENA can fine successively the concessionaire in case he fails to fulfil points 2, 3, 4, 5, 6, 8, 10, 12, 14, 15 and 16 set out in Clause II.

CLAUSE XII

The concession will cease in case of:

1. Dissolution of the Company;
2. Bankruptcy of the Company;
3. Failure to fulfil points 1, 2, 3, 6, 7, 8, 9, 10, 11, 12, 13, 14 of Clause II;
4. Failure to fulfil the management plan;
5. Failure to fulfil Clause III.

CLAUSE XIII

When the cause is one of the points: 1, 2, 3, 4, and 5 of the last clause, the concessionaire will receive notice and prepare his defense within 30 days.

CLAUSE XIV

No new concession will be entrusted to the concessionaire for a period of five years after the concession agreement has been declared void.

CLAUSE XV

This contract may be extended upon agreement between the two parties.

CLAUSE XVI

This contract will be published in the Official Bulletin... at the cost of the concessionaire.