Logging Costs Research Articles

Optimization of Road Spacing for Log Length Shovel Logging on Gentle Terrain

Shovel logging has become a popular logging system in the western United States due to its high productivity. Its low ground pressure and single pass, often on a matt of limbs result in little ground disturbance. Despite this increasing popularity, there have been few operational studies of shovel logging. This paper describes the optimal road spacing problem for shovel logging using a serpentine pattern on gentle terrain. A mathematical model for shovel logging is presented for two cases (1) to minimize the sum of shovel yarding costs plus road costs from the landowner’s point of view and(2) to maximize profits from the point of view of a logging contractor. For the operating conditions assumed, the optimal shovel yarding distance is four swings when shovel yarding plus roads costs are minimized and three swings when logging contractor profit is maximized. For the example data, the model results demonstrate the flexibility of shovel logging in that there is little difference between total road construction plus skidding cost from the optimal number of swings to as many as six swings. Sensitivity analysis was performed on road cost and volume per ha and support the stability of the solution with the minimum logging cost occurring at four swings with just a small difference for as many as six swings over a range of road construction and volume removals.

New Subsea Technology Aims To Cut Well-Intervention Costs

Deepwater subsea well intervention must be done with mobile offshore drilling units (MODUs), which can be very expensive. The cost per intervention using the standard MODU averages up to U.S.$10 million, in addition to the lost or deferred production. With deepwater production poised to play an even greater role in meeting global hydrocarbons demand, those costs will become increasingly burdensome. A new technology unveiled by ExxonMobil promises to mitigate this costly expense and significantly reduce the cost and time of downhole logging, acidizing, and other interventions in deepwater oil and gas wells. The subsea-intervention-module (SIM) technology offers a riserless way to deploy a seafloor coiled-tubing (CT) unit from a specially designed support vessel. ExxonMobil says the new technology, which it has been working on for the past 4 years, is advanced well beyond concept stage and has undergone significant high-risk engineering and component testing. The technology is now entering the detailed design and construction phase, and it will undergo further development to complete its design and its integration with subsea facilities. The SIM system—compromising a subsea CT system and a purpose-built monohull vessel that provides deployment, control, and support—is designed for use in 2,000 to 6,500 ft of water and can be used in even deeper subsea production interventions. It will be able to accommodate well depth of up to 13,000 ft below the seafloor. The system can be used for intervention on any subsea well constructed with 36-in. structural casing and completed with a horizontal tree. First use of the technology will be offshore west Africa in 2008. To commercialize the technology, ExxonMobil has licensed the SIM system to a joint venture between BJ Services Co. and Otto Candies LLC. The venture will operate the SIM system following the completion of design and construction. SIM Support Vessel The SIM system consists of the vessel—consisting of a dynamically positioned vessel, compensated deployment system, and controls—and the tool, which includes the CT module, blowout-preventer (BOP) module, one-way fluid-transfer lines, and remotely operated vehicle (ROV) with power and control umbilical. The SIM support vessel is a monohull vessel with double skin, a large working moonpool, and diesel/electric propulsion with a dynamic-positioning system. The vessel is the mother ship for the subsea CT unit. The self-supporting vessel carries stores and supplies for a 30-day period to support multiple well-intervention missions and can be replenished at sea if needed. The vessel also contains a helicopter deck and mooring facilities on both sides for a supply vessel. The vessel is 372 ft long and 79 ft wide, with an 18-ft draft (Fig. 1). It can accommodate up to 97 people and operate in up to 6,500 ft of water depth. The moonpool is 43×36 ft and located in the middle of the vessel, with a 750-ton, single-wire Huisman deployment system above. The vessel also includes deployment capability of two ROVs. A state-of-the-art control room includes the SIM control station, two ROV control stations, and a system to control and monitor CT operations and deployment.

Social and Environmental Costs of Illegal Logging in a Forest Management Unit in Eastern Cameroon

Cameroon's forests have experienced the development of a flourishing informal forestry sector. This case study was designed to provide detailed information on illegal logging in the East Province of Cameroon, Messok district and focuses on Forest Management Unit (FMU) 10 030. Between 1999 and 2000, 21,750 ha of the unit's 79,757 ha (27%) was logged illegally. In total, 162,255 m3 (7.46 m3 per ha) of timber worth approximately US$ 26.5 million were removed from this area. The area logged is equivalent to 8.2 annual cut blocks which should have generated US $7.5 million in tax revenues. Locally, no long-term investments were made and the employment generated by the logging operations lasted only 2 years. Imposing sanctions against companies responsible for illegal logging activities remains an untested approach in Cameroon. The company recently challenged the administration's decision at the administrative court, on the grounds of the lack of evidence, and won the case. There is a risk that the company will escape all legal charges because of a four-year statute of limitations on tax infractions. The FMU 10 030 case shows the extent of financial and environmental damages from illegal logging and gives an idea of the level of losses incurred in Cameroon and other countries in the Congo Basin.

Financial and ecological indicators of reduced impact logging performance in the eastern Amazon

Reduced impact logging (RIL) systems are currently being promoted in Brazil and other tropical countries in response to domestic and international concern over the ecological and economic sustainability of harvesting natural tropical forests. RIL systems are necessary, but not sufficient, for sustainable forest management because they reduce damage to the forest ecosystem during the initial forest entry. If conditions were identified where RIL costs were clearly less than conventional logging (CL) costs, then a strong incentive for RIL adoption would exist. In this paper, a comparison of costs and revenues was made for typical RIL and CL operations in the eastern Amazon. An economic engineering approach was used to estimate standardized productivity and cost parameters. Detailed data on productivity, harvest volume, wasted wood and damage to the residual stand were collected from operational scale harvest blocks. Productivity and cost data were also collected using surveys of forest products firms. The major conclusion of the study was that RIL was less costly, and more profitable, than CL under the conditions observed at the eastern Amazon study site. Full cost accounting methods were introduced to capture the direct and indirect costs associated with wasted wood. The impact of wasted wood on effective stumpage price provided the largest gain to RIL. Large gains attributable to RIL technology were also observed in skidding and log deck productivity. In addition, investment in RIL yielded an “environmental dividend” in terms of reduced damage to trees in the residual stand and reduction of the amount of ground area disturbed by heavy machinery. Developing institutions that can monetize the value of the environmental dividend remains a major challenge in the promotion of sustainable forest management in the tropics.

Comparison of two cut-to-length harvesting systems operating in eastern hardwoods

We compared production rates, operating costs, and break-even points (BEP) for small and large cut-to-length (CTL) harvesting systems operating at several machine utilization rates (MUR) in mixed hardwood and softwood stands in Vermont. The small CTL harvester produced 11.08 m3 [391.4 ft3] per productive machine hour (PMH) compared to 14.83 m3 [523.80 ft3] per PMH for the large harvester. The impact of average tree size (volume) on cost was substantial but similar for both CTL systems. At a fixed stump-to-landing logging cost of about $14.12/m3 or [$0.40/ft3], the BEP tree size was 0.14 m3 [5.0 ft3] for the small harvester and 0.26 m3 [9.33 ft3] for the large system at the 85 percent MUR. At an MUR of 70 and 85 percent, the processing cost for trees that averaged 0.08 m3 [3.0ft3] was $22.19 and $18.28/m3 [$0.6285 and $0.5176/ft3], respectively, for the small CTL harvester. Results were similar for the large harvester. Either CTL system would be effective in helping managers meet forest management goals in eastern hardwood stands.

Why Poor Logging Practices Persist in the Tropics

Abstract: Despite abundant evidence that both the environmental damage and the financial costs of logging can be reduced substantially by training workers, pre‐planning skid trails, practicing directional felling, and carrying out a variety of other well‐known forestry practices, destructive logging is still common in the tropics. Based on our collective experience with loggers in tropical forests, we discuss seven possible reasons for this seemingly irrational behavior. The principal reason poor logging practices persist is apparently that the widely heralded cost savings associated with reduced‐impact logging relative to unplanned logging by untrained crews may not be realized under some conditions. In particular, where compliance with logging guidelines restricts access to steep slopes or prohibits ground‐based timber yarding on wet ground, reduced‐impact logging may be synonymous with reduced‐income logging. Given that under such conditions loggers may not adopt reduced‐impact logging methods out of self‐interest, fiscal mechanisms for promoting sustainable forest management may be needed.

The role of peatlands in Finnish wood production – an analysis based on large-scale forest scenario modelling

Using the Finnish MELA model, a set of scenarios were produced and used to map the possibilities and risks surrounding the utilisation of peatlands in wood production in Finland. One of the scenarios was an estimate of allowable-cut calculated by maximising the net present value of the future revenues using a four per cent interest rate subject to non-decreasing flow of wood, saw logs and net income over a 50-year period, and net present value after the 50 year period greater or equal than in the beginning. The estimate for maximum regionally sustained removal in 1996–2005 was 68 million m3 per year – approaching 74 million m3 during the next decades. In this scenario, 14 per cent of all cuttings during the period 1996–2005 would be made on peatlands, which comprise ca. 31 per cent of the total area of forestry land. By the year 2025, the proportion of peatland cuttings would increase to over 20 per cent. The increase in future cutting possibilities on peatlands compensated for a temporary decrease in cuttings and growing stock on mineral soils. The allowable-cut effect was especially pronounced in northern Finland, where peatlands play an important role in wood production. In addition, the sensitivity of cutting possibilities for assumptions related to growth and price were analysed. The estimate of maximum sustainable yield as defined here seems to be fairly robust on the whole, except in northern Finland where the cutting scenarios were sensitive to the changes in the price of birch pulpwood. The proportion of peatland stands that are profitable for timber production depends on the interest rate: the higher the rate of interest the less peatland stands are thinned. The effect of cutting profile on future logging conditions and resulting costs were analysed in two forestry centres. If clear cuttings on mineral soils are to be cut first, an increase in future logging costs is inevitable.

Better utilisation of the skidder winch can decrease the overrun on the logging site

SYNOPSIS A study of seven articulated wheel skidders was conducted at five different locations, where the winch line was pulled out for a distance of up to 60 metres from the skid trail. The further the winch line is pulled porn a skid trail to hitch a load, the further apart the skid trail spacing can be, with the resultant decrease in the negative effects of the skidder on the logging site. Winching skidder pay loads from beyond the usual 10 metres will involve a productivity and a cost penalty. The effect of a long winching distance on the productivity and cost of logging and its effect on the logging site is discussed.

Logical logging to extend recovery to new domains

Recovery can be extended to new domains at reduced logging cost by exploiting “logical” log operations. During recovery, a logical log operation may read data values from any recoverable object, not solely from values on the log or from the updated object. Hence, we needn't log these values, a substantial saving. In [8], we developed a redo recovery theory that deals with general log operations and proved that the stable database remains recoverable when it is explained in terms of an installation graph. This graph was used to derived a write graph that determines a flush order for cached objects that ensures that the database remains recoverable. In this paper, we introduce a refined write graph that permits more flexible cache management that flushes smaller sets of objects. Using this write graph, we show how: (i) the cache manager can inject its own operations to break up atomic flush sets; and (ii) the recovery process can avoid redoing operations whose effects aren't needed by exploiting generalized recovery LSNs. These advances permit more cost-effective recovery for, e.g., files and applications.

A Study on the Productivity and Cost of Cable Logging in Turkey

Tower yarders have recently been introduced to forestry in Turkey. Clarification of the productivity and cost of logging using the tower yarder is often requested because the cost for machinery is a significant factor in all calculations concerning mechanized operations. Machines are often extremely expensive compared with the low cost of labor in developing regions. In this study, a new logging system using a tower yarder was compared with a conventional system using a stationary yarder in terms of productivity and cost. The research was conducted in the northeast of Turkey, in 1989 and 1992. The productivity of the tower yarder and the stationary yarder was found to be 5.655 m3/h and 5.002 m3/h, respectively. Harvesting cost was analyzed based on observed productivity. The harvesting costs of the tower yarder and the stationary yarder were found to be 47,410 TL/m3 and 17,553 TL/m3, respectively. With the tower yarder, the machine cost reached 93.1 % of the harvesting cost while the machine cost using the stationary yarder reached 71.1%.

Production structure, factor substitution, technical change, and total factor productivity in the Canadian logging industry

The production structure of the Canadian logging industry is studied using duality theory in production and costs. An unrestricted translog cost function and nine restricted cost functions are each estimated simultaneously with the cost share equations using the Iterative Zellner method. The Allen and Morishima elasticities of substitution among pairs of inputs and price elasticities of factor demands are computed. The difference between the rate of technical change and the total factor productivity is discussed, and both are calculated. Finally, an average cost equation is calculated and the impacts of factor prices are determined. The results indicate that the production structure is homogeneous, but it is not subject to the unitary elasticity of substitution, Hickis neutral technical change, or no technical change. The Morishima elasticities indicate that the substitution of capital by labour or energy is easier than the substitution of labour or energy by capital. Substantial economies of scale are observed in the logging cost. In the rate of technical change, the acceleration term dominates the input factors contribution, and the rate of technical change is negative in all the years. In the total factor productivity growth, in most of the years, the rate of technical change dominates the scale effect. Average cost is the most sensitive to material price followed by labour price, and the least sensitive to energy price.

Derivation of stumpage value and logging costs for individual forest stands using aerial photographs and cartographic modelling

A procedure for calculation of stumpage value and logging costs of individual mature forest stands using aerial photo‐interpretation and a grid‐based geographical information system (GIS) is presented. The stumpage value may be computed from characteristics related to the trees, i.e. site index, stand mean height, crown closure, and tree species distribution, using price equations. By means of cost equations, the logging costs may be calculated from the tree characteristics and the terrain characteristics of slope gradient and skidding distance. The practical application of the procedure was demonstrated by a case study in a 710 ha forest area in southern Norway. The tree characteristics were determined by photo‐interpretation of individual stands. Skid paths for wood transportation from the stands to landings along the forest roads were delineated by photo‐interpretation of the ground conditions. Slope and skidding distances were derived by a digital elevation model and cartographic modelling. Finally, the photo‐interpreted tree characteristics and the computed slope and skidding distances were used for calculation of the stumpage value and the logging costs of each stand. According to previous tests, the accuracy of the procedure corresponded to the accuracy that could be achieved by the field‐survey methods used most frequently.

Determination of stumpage value and logging costs in coniferous forest stands by means of aerial photo‐interpretation

One model for determination of stumpage value per cubic metre and two different models for determination of logging costs per cubic metre of final fellings were developed by using attributes derived by aerial photo‐interpretation. Input variables of the models were stand mean height, crown closure, site quality, tree species composition, slope, and skidding distance, and average number of trees per cubic metre and average tariff number derived from a stratified field sample plot inventory. Intensive field measurements of 119 mature coniferous stands were used to test the models. Aerial photographs at the approximate scale of 1 : 15 000 were used for photo‐interpretation. The bias of the estimated stumpage value was in the range ‐3.3% to 5.2%. The standard deviation was 2.3–10.8%. For the estimated logging costs the bias was in the range ‐10.5% to 2.9%. The standard deviation was 4.2–11.7%.

DO HIGH DISCOUNT RATES DESTROY TROPICAL FORESTS

The short-term viewpoint implicit in high discount rates seems to favour immediate forest exploitation rather than conservation for perpetual benefits. However, the value of logging revenues increases with a lower discount rate, because of the greater weighting given to investible funds. Thus, in several theoretical models, net present value of logging increases as discount rate is lowered. In practice, however, long-term costs of logging may also incur the weighting appropriate to investment funds; reinvestment of logging revenues may not actually take place; and lower discount rates may be appropriate for costs but not revenues. These circumstances favour conservation, the more so at lower discount rates.

Financial Returns from Fertilizing 70-year-old Lodgepole Pine near Hinton, Alberta

Fertilizing 70-year-old lodgepole pine stands 10 years before rotation on Coalspur Mercoal soils in Alberta increased wood yield and reduced logging costs. Real internal rates of return were over 10% for some treatments, making them an attractive investment on both soil types. Present net worth and profitability index were used to identify the most profitable treatment. Key words: Forest fertilization, lodgepole pine, returns from fertilization, profitability, investments in lodgepole pine, management of lodgepole pine, cost-effectiveness of fertilization, fertilization of preharvest lodgepole pine.

Tree Size and Species, Stand Volume, and Tract Size: Effects on Southern Harvesting Costs

Abstract Timber harvesting production rates and equipment and labor costs were used to estimate average logging costs for a variety of tract volumes and sizes, stand structures, and tree species. Average costs were estimated for conventional logging systems typical in the South. Regression analysiswas used to identify significant factors affecting the costs for each system. Highly mechanized systems were generally cheapest for harvesting southern pines, but were not much cheaper for harvesting hardwoods. Hardwoods were substantially more expensive to harvest, as were tracts of lessthan 250 cords in total volume. South. J. Appl. For. 13(3):145-152.

Harvesting Factors Affecting Financial Feasibility of Thinning in Southwestern Idaho

Abstract The financial feasibility of thinning in southwestern Idaho is not well established. A logging cost model, LOG-COST, was developed to estimate harvesting costs for seven major tree species. The financial feasibility of thinning depends heavily on species, tree size, skidding or yarding method, topography, and truck transport distance. In order to provide financially feasible thinnings, biologically similar stands may have to be managed quite differently if truck transport distance or terrain vary significantly. West. J. Appl. For. 2(4):105-110, October 1987.

Bucking Logs to Cable Yarder Capacity Can Decrease Yarding Costs and Minimize Wood Wastage

Abstract Data from selected time and motion studies and a forest model plot, used in a simulation model, show that logging managers planning felling, bucking, and limbing for a cable yarding operation must consider the effect of alternate bucking rules on wood wastage, yarding production rates and cost, the number of chokers to fly and total logging costs. Results emphasize the need to consider initial logging activities in terms of effects on cable yarding system efficiencies and wood wastage. Results also emphasize the need to match payload (piece size) to cable yarder capacity. Results suggest that cable yarding costs can be decreased by 20 to 32% by simply bucking logs to yarder capacity. South. J. Appl. For. 10:180-183, Aug. 1986.

Estimating and Valuing Western Pine Beetle Impacts

Abstract A tree growth and mortality model was developed to simulate timber production with and without tree mortality caused by the western pine beetle, Dendroctonus brevicomis LeConte. Stumpage value at time of harvest was discounted back to the time of mortality. A logging cost model was used to estimate revenue generated from salvaging killed trees. These values were assembled to estimate the value at risk from western pine beetle-caused tree mortality. Simulated estimates of beetle impact were affected by interest rate, time of final harvest, spatial aggregation of mortality, and distribution of mortality in relation to tree diameter and stand density. The model developed here simplified certain biological relationships. Its development highlighted the lack of quantitative data on biological factors affecting western pine beetle impact. Forest Sci. 32:325-338.

Stump-to-Truck Cable Logging Cost Equations for Young-Growth Douglas-fir

Abstract Logging cost simulators and data from logging cost studies have been assembled and converted into a series of equations that can be used to estimate the cost of logging young-growth coastal Douglas-fir. (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) in mountainous terrain of the Pacific Northwest. These equations were developed for two small cable yarders and one medium-sized yarder and are applicable for harvests of timber from 6 to 24 inches in diameter on slopes of 10 to 50%. Cost components can be easily Calculated on a hand calculator. A computer program that can be adapted to many desktop computers and that will calculate the total stump-to-truck logging cost for a specified set of logging conditions is also available. West. J. Appl. For. 1:19-21, Jan. 1986.