In order to provide bridge designers with better information, International Forest Products Limited (Interfor) asked the Forest Engineering Resarach Institute of Canada (FERIC) to evaluate the bending strength and stiffness of log stringers used for constructing bridges on forest roads in coastal British Columbia. Given the lack of definitive standards for testing this material, FERIC developed a field-based test procedure and designed a test facility for destructive testing of full-size, whole-log stringers obtained from second-growth stands. Sixteen coastal Douglas-fir and twelve western hemlock logs were tested in 2003. This report describes the test procedure and methods of analysis, presents the log bending strength and stiffness results, and makes recommendations regarding future testing.
With the appropriate mainline attachment, chain chokers are a viable alternative to conventional wire rope chokers, particularly for small-scale operations. This report provides users of tractor-mounted winches and cable skidders with technical information on chain chokers. The report covers type of steels, chain specifications and grades, and how to inspect chains for wear elongation. The various components (e.g. sliding hooks, rings) used to assemble chain chokers are also discussed.
This study tested ultra-high molecular weight polyethylene (UHMWPE) ropes for log load securement. Destructive testing of used rope samples done in a previous project found that the strength of these ropes decreased with use. To address this problem, the diameter of the synthetic rope was increased. In addition, a different type of rope with a UHMWPE inner core covered with a polyester protective jacket was tested. The outer jacket protected the inner core from dirt and abrasion which may help mitigate the loss in strength that occurs with use. Wrappers were put into service and tested for breakage after three and six months of use.
When forest harvesting equipment moves across a cutblock, soil compaction and/or rutting can result. Forest practitioners are therefore concerned about the long-term effects of harvesting on forest soil health, water quality, and tree growth. The purpose of this handbook is to provide practical advice to forestry contractors and equipment operators, and their field supervisors, about the risk of damage to forest soils during harvesting operations, and how to avoid it. The opportunity to protect forest soil occurs at each step of the forestmanagement process, from harvest planning to field layout to harvesting and post-harvesting activities. Operators of forestry equipment, harvesting contractors, and field supervisors are vital links in this process. To help identify when the health of forest soil is at risk, this handbook offers a brief introduction about forest soils, and explains why and how soil is susceptible to damage. The soil terminology used is defined in a glossary along with other equipment related terms (Appendix I). For harvesting contractors and equipment operators, the handbook explains how visual indicators like landscape features and tree species can be used to estimate soil moisture, and offers simple field tests to help them anticipate when soils become at risk. For contractors, equipment features that influence soil compaction and rutting are discussed, and operating techniques to reduce soil damage are suggested. For field supervisors, harvest scheduling options that minimize soil damage are included. As well, the handbook offers ways to modify harvesting operations when soils have become susceptible to damage. Maintaining soil health during harvesting requires knowing when soils are at increased risk of compaction and rutting, and understanding how equipment operation interacts with the soil. If contractors, operators, and field supervisors can anticipate susceptible soil types and conditions, they will be able to plan ahead and make changes to their operating schedules and techniques. Recommendations made in this handbook regarding equipment and operating techniques are to serve as guidelines only. Local operating conditions and regulations, as well as equipment availability, must be considered when interpreting this information.
FERIC has produced a guide for equipment operators, contractors and their field supervisors aimed at preventing soil damage from forest operations. A brief description of soils and soil damage categories is provided as are recommendations for choosing equipment options and operating techniques that reduce damaging soil disturbance.
The Forest Engineering Research Institute of Canada (FERIC) studied a summer roadside harvesting operation in a hardwood-dominated mixedwood stand in central Alberta. This report describes the in-block soil compaction resulting from the felling and skidding phases.
Cette étude a évalué des câbles en polyéthylène de poids moléculaire ultra élevé (PEPMUE) pour sécuriser des chargements de billes. Des tests destructifs d'échantillons de câbles usagés effectués dans un projet précédent avaient révélé que la résistance de ces câbles diminuait avec l'utilisation. Pour résoudre ce problème, le diamètre du câble synthétique a été augmenté. De plus, un autre type de câble avec une âme intérieure en PEPMUE recouverte d'une gaine de protection en polyester a été testé. La gaine extérieure protégeait le câble intérieur de la saleté et de l'abrasion, ce qui peut aider à atténuer la perte de résistance qui se produit avec l'utilisation. Les câbles ont été mis en service et testés pour la résistance à la rupture après trois et six mois d'utilisation.