Marchi Enrico, PhD. Assoc. Prof.

Forest roads play a key-role in fire fighting activities. In fact, all ground-based activities are
strictly related to the presence of forest roads as access to fire edge. In spite of this important
role, forest roads are often planned and built without considering their use in fire fighting, and
this also occurs in literature, where few studies are dedicated to the importance of forest roads
in fire fighting. A well-developed and well-maintained forest road network is the answer to
different needs in fire management. The objective of this review is to clarify basic principles
for obtaining efficient road network also for fire fighting, collecting, defining and resuming
the main roles, the most important aspects and the reported experiences to be taken into account
in forest road network planning and maintenance in fire-prone areas. The most important
themes treated are related to: i) the analysis of the functions of forest roads in fire prevention
and suppression; ii) the importance of forest road planning and building also considering their
importance for protecting forests against fires: iii) the construction and maintenance characteristics
to be considered for building and maintaining an efficient forest road network against
fires; iv) the importance of fire prevention and the related role of forest roads. Special attention
has been dedicated to maintenance activities, because a not well-maintained forest road is a
not efficient forest road, and it represents a useless economic and environmental cost.

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.

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.

Tree felling with a chainsaw is one of the most dangerous operations, but it cannot be replaced by machines in many areas. Operators are exposed to many hazards including accidents, fatigue, fumes, dust, noise and vibration. This research focuses on vibration exposure and on how it is affected by the accuracy of saw chain maintenance. Although chain sharpening must be carried out according to the manufacturer's instructions, it is common practice to make errors in sharpening angle and chain depth gauge lowering. The aim of the study is to investigate the variations in both cutting efficiency and vibration exposure, considering three different depth gauge lowering levels (standard: 0.65 mm, over-standard: 1.0 and 1.3 mm) when cross-cutting several square beams of two species: European beech (high density) and silver fir (low density). The results show that the increase in cutting efficiency at higher depths was statistically significant for silver fir beams but limited overall (about 10%). On the other hand, the over-standard lowering of the depth gauge did not reduce the cutting time on beech. On the contrary, vibration exposure increased significantly from a minimum of 64% to a maximum of 133% compared to the standard level. These results show that the practice of lowering the depth gauge beyond the standard level is dangerous for the operator and has no real benefit in terms of cutting performance.

Tree felling with a chainsaw is one of the most dangerous operations, but it cannot be replaced by machines in many areas. Operators are exposed to many hazards including accidents, fatigue, fumes, dust, noise and vibration. This research focuses on vibration exposure and on how it is affected by the accuracy of saw chain maintenance. Although chain sharpening must be carried out according to the manufacturer's instructions, it is common practice to make errors in sharpening angle and chain depth gauge lowering. The aim of the study is to investigate the variations in both cutting efficiency and vibration exposure, considering three different depth gauge lowering levels (standard: 0.65 mm, over-standard: 1.0 and 1.3 mm) when cross-cutting several square beams of two species: European beech (high density) and silver fir (low density). The results show that the increase in cutting efficiency at higher depths was statistically significant for silver fir beams but limited overall (about 10%). On the other hand, the over-standard lowering of the depth gauge did not reduce the cutting time on beech. On the contrary, vibration exposure increased significantly from a minimum of 64% to a maximum of 133% compared to the standard level. These results show that the practice of lowering the depth gauge beyond the standard level is dangerous for the operator and has no real benefit in terms of cutting performance.