Spinelli Raffaele, PhD.

Productivity of Processing Hardwood from Coppice Forests

volume: 33, issue: 1

Integrating Animal and Mechanical Operations in Protected Areas

volume: 32, issue: 2

Comparing Terrain and Roadside Chipping in Mediterranean Pine Salvage Cuts

volume: 32, issue: 2

A Low-Investment Fully Mechanized Operation for Pure Selection Thinning of Pine Plantations (p.89-97)

volume: 30, issue: 2

Harvesting Short-Rotation Poplar Plantations for Biomass Production (p.129-139)

volume: 29, issue: 2

Recovering logging residue: experiences from the Italian Eastern Alps

volume: 28, issue: 1

Resistance coefficients on ground-based winching of timber

volume: 26, issue: 1

Evaluating Efficiency, Chip Quality and Harvesting Residues of a Chipping Operation with Flail and Chipper in Western Australia

volume: 34, issue: 2

Long Term Repair and Maintenance Cost of some Professional Chainsaws

volume: 34, issue: 2

Effect of Chipper Type, Biomass Type and Blade Wear on Productivity, Fuel Consumption and Product Quality

volume: 35, issue: 1

Soil Compaction and Recovery after Mechanized Final Felling of Italian Coastal Pine Plantations

volume: 35, issue: 1

Comparison of Cost Efficiency of Mechanized Fuel Wood Thinning Systems for Hardwood Plantations on Farmland

volume: 35, issue: 2

Effects of Sieve Size on Chipper Productivity, Fuel Consumption and Chip Size Distribution for Open Drum Chippers

volume: 36, issue: 1

Cable Logging Contract Rates in the Alps: the Effect of Regional Variability and Technical Constraints

volume: 36, issue: 2

A Single-pass Reduced Tillage Technique for the Establishment of Short-Rotation Poplar (Populus spp.) Plantations

volume: 37, issue: 1

Forest Workers and Steep Terrain Winching: the Impact of Environmental and Anthropometric Parameters on Performance

volume: 37, issue: 1

Trends and Perspectives in Coppice Harvesting

volume: 38, issue: 2

Productivity, Efficiency and Environmental Effects of Whole-Tree Harvesting in Spanish Coppice Stands Using a Drive-to-Tree Disc Saw Feller-Buncher

volume: 39, issue: 2

Whole tree harvesting was conducted on two coppice stands with different tree composition
(Q. ilex and Q. pyrenaica) in gentle terrain. Felling and bunching were performed by a
drive-to-tree wheeled feller-buncher with disc saw head. Operations were analyzed on 17 plots
25x25 m2 in order to develop productivity models and to assess operational costs. The study
also aimed at determining biomass collection efficiency and evaluating the impact of the new
harvesting method on the soil, the remaining trees and stumps. The treatment consisted in a
strong coppice thinning leaving standards. Productivity ranged from 2.8 to 4.6 odt/pmh in
the Q. ilex coppice, and from 0.9 to 2.6 in the Q. pyrenaica stand. Tree species, dry weight
per tree and percentage of removed basal area were the main independent variables affecting
productivity. Approximately 50% of the standards showed damages. Most wounds were light,
caused by the drive-to-tree work pattern, followed through GPS tracking. Soil damage was
also light; in no plots, deep disturbances were found. However, most of the stumps were damaged.
Forwarding and chipping productivity and cost were also evaluated. The slash left on
the terrain averaged 3.0 and 1.5 odt/ha in Q. ilex and Q. pyrenaica, respectively, including
scrub debris. As a conclusion, while this heavy feller-buncher can be useful in coppice heavy
thinnings with larger trees, it would be a good option to try lighter disc saw felling heads
mounted on the harvester boom tip, which probably would reach better productivity and reduce
the frequency of stand damage.

Production of Wood Chips from Logging Residue under Space-Constrained Conditions

volume: 39, issue: 2

A study was conducted on chip production from logging residue left after a cable yarder operation.
The logistics were managed with tractor and trailer units (shuttles). The study specifically
dealt with a very difficult case of space constrained operations, further expanding the
knowledge about chip supply in extreme work conditions. The focus of the investigation was
also extended to the shuttles. The study tested a production chain, in which only 3 machines
(1 chipper, 2 shuttles) were used to minimize operational costs. The use of 2 shuttles was decisive,
reducing shuttle delays. The chips produced had an average moisture content of 40.2 ±3.1%.
Particle size distribution shows an unfavorable composition. The content of accepts is as low
as 72%, while oversized particles get up to 5.4% and fines rise to a maximum of 24%. The
estimated net productivity of the whole system was 11.5 t PMH-1, corresponding to a gross
productivity of 11.1 t SMH-1. The cost of the whole operation amounted to 21.2 €t-1.

Productivity and Utilization Benchmarks for Chain Flail Delimber-Debarkers-Chippers Used in Fast-Growing Plantations

volume: 40, issue: 1

The study developed robust benchmark figures for the performance of delimber-debarker-chippers
in fast-growing eucalypt plantations, through the analysis of an exceptionally large database
that combined automatically-captured and user-input records. Data for three Peterson
Pacific DDC 5000 H units operated by the Brazilian company Fibria Cellulose were captured
continuously for three years, from 2015 to 2017. During this time, all study machines ran
triple-shift and clocked over 25 000 hours each. The consolidated record included information
for 79 858 delay events, with an average duration of 0.55 hours per event. Delay time accounted
for 57% of total worksite time: mean utilization was therefore 43%. Maintenance was
the most important cause of delays, and accounted for 22% of total worksite time. Interaction
delays came second, and represented 20% of total worksite time. Mean productivity was
88 solid m3 ub (under bark) per productive machine hour (PMH) or 39 solid m3
ub per scheduled machine hour (SMH), depending on whether delay time was excluded or included in the
calculation. The gap between the most efficient and the least efficient operator was 22% and
26% for scheduled productivity and utilization, respectively (this difference was calculated by
taking the figures for the lowest performer as a basis). While the exact productivity figures
reported here may reflect the exceptionally favorable conditions encountered in rationallymanaged
South American plantations, the dynamics revealed in this study may have general
validity and could offer precious insights for rationalizing a whole range of similar operations.

Manipulating Chain Type and Flail Drum Speed for Better Fibre Recovery in Chain-Flail Delimber-Debarker-Chipper Operations

volume: 41, issue: 1

A chain-flail delimber-debarker-chipper (CFDDC) was adapted for treating smaller trees than normal by replacing the standard flails with lighter ones, and by reducing flail drum rotation speed. The machine produced 16 full containers (24 t each) for the standard configuration and 24 full containers for the innovative one. For each container the researchers measured: original tree mass, chip mass, time consumption and fuel use. Results indicated that the innovative setting accrued a 12% improvement on fiber recovery compared with the standard setting (control). At the same time, productivity increased by 20% and fuel consumption was reduced by 30%. Product quality was largely unaffected, with bark content remaining below the 1% threshold specification. If at all, product quality was improved through the reduction of fine particles, possibly derived from less diffused fraying. These results have triggered the real scale adoption of the new setting by contractors who participated in the study. The success of the innovative treatment is likely explained by its better alignment with the weaker structure of small trees from low-yielding stands.

The Effect of New Silvicultural Trends on Mental Workload of Harvester Operators

volume: 41, issue:

Close-to-nature (CTN) forestry offers many advantages, but makes management more complex and generally results in lower harvesting productivity and higher harvesting cost. While the higher harvesting cost of CTN is widely acknowledged, few ever consider the potential impact on operator workload, as the harvesting task becomes more complex. This study aimed to determine the mental workload of harvester operators under two silvicultural regimes: »pure conifer« stand and »mixwood« stand. In total, 13 harvester operators with varying experience levels were monitored for work performance and mental workload when operating a harvester simulator in two virtual stands designed according to the above-mentioned silvicultural regimes. Mental workload was assessed using the NASA Task Load Index (NASA-TLX) interview method and heart rate variability measurements, during two 30-minute test sessions performed in the »pure conifer« and the »mixwood« stand, respectively. As expected, operating in a more diversified »mixwood« stand resulted in a marked productivity loss, estimated between 40 and 57%. The study also confirmed the increased aggravation of mental demand, effort and frustration experienced by the operators when passing from the »pure conifer« stand to the »mixwood« stand. Such increase in mental workload was independent of the age and experience of the operators. Results can be used to paint a more holistic picture of CTN forestry and its implications for harvester operators. Besides increasing the number of subjects being monitored, future studies should focus on live forest operations.

A Proposal for an Integrated Methodological and Scientific Approach to Cost Used Forestry Machines

volume: 42, issue:

This paper offers a conceptual analysis of the unaccounted-for cost of owning and operating used machines from an operational, financial and market perspective. It is based on input from experts and a literature review. In the scientific literature, assessing the operating cost of used machines in forest operations is typically based on standard cost assessment methods using costing/pricing input from similar unused machines. This is the case since there are usually no historical data for observed used machines available to analyze. This substitute analysis is problematic to many used and depreciated machines owners. The changing trends in forest technology attest that old machinery do not hold to the same input cost data variables or values of new machines. In fact, they belong to two rather competing different markets: (used vs. new equipment markets). With the technological, market and machinery regulations and dynamic changes, the substitute cost analysis is not representative. Better data is required to understand the cost of owning and operating used machines and the justification is the focal point of this paper. The outcome of the expert and literature analysis in this paper demonstrates that a broader understanding of the cost of a used machine is required and doable. A proposed understanding integrates the machine availability (performance), cost factors (financial) and market evaluation (price), in isolation (single piece of machine) as well as in a fleet, to assess a used machine ownership cost. The study is intended to offer forest machine operators, owners, scientists, and practitioners a proposed new approach to value used machines and further investigations and data inputs required to make used machines costing methods more relevant.

Trends and Perspectives in the Design of Mobile Wood Chippers

volume: 42, issue:

Mobile wood chippers represent a mature technology now available in a wide range of sizes and configurations. Different types exist, but the most widespread are disc and drum chippers. The latter have enjoyed wider popularity in recent years because they are best suited to processing logging residue and other low-quality wood. Drum chippers can be fitted with screens, designed to re-circulate oversize particles. In general, industrial chippers offer high productivity and high fuel efficiency, especially if settings are properly adjusted. Chippers are high-maintenance equipment and require proper care. Maintenance cost increases with machine age and can be predicted quite accurately, and so can chipping productivity and cost. Reliable models exist for estimating both maintenance cost and productivity, based on dedicated user-entered assumptions. All things being equal, there are no substantial productivity and maintenance differences between tractor-powered and independent-engine chippers.


Web of Science Impact factor (2019): 2.500
Five-years impact factor: 2.077

Quartile: Q1 - Forestry

Subject area

Agricultural and Biological Sciences