Appropriate Forest Harvesting and Transport Technologies for Village-based Production of Bamboo Charcoal in Mountainous Areas of Northern Lao PDR. Forest harvesting and transport operations lie on a near-optimal path for creating conflict. Thus their careful implementation is important not. FSC have also been able to help the farmers in facilitating with the harvesting and transportation costs. FSC through the field division is responsible for the.
and transport Harvesting
Forestry Commission Project Report 49 The Fibre-gen Hitman Acoustic Tool is a harvester-head mounted device for measuring wood density, as an aid to timber grading. This report describes field trials to retrofit the tool to a Ponsee harvester head to evaluate performance.
The fitting and positioning of the components of the acoustic system onto the existing Ponsee H75 harvester head was well planned by the engineers. The components were well guarded by additional steel fabrications.
No problems were encountered with the actual hammer and receiver unit. A minor problem was noted with the electrical cable of the acoustic tool being strapped to hydraulic hoses inside the harvester head housing. As the hose heated and expanded, the tie strap tightened around the cable prohibiting the electrical connection.
There was no time difference between the production of acoustic quality QA and non acoustic NAQ sawlogs when using the acoustic tool. The acoustic tool identified logs, suitable as sawlog material that otherwise would have been downgraded due to stem straightness, buttressing, number of knots, knot size and stem roughness as per Forestry Commision Fieldbook 9: Classification and presentation of softwood sawlogs.
Forest operations in steep terrain - Evaluation of Silvatec Sleipner TH purpose-built 8-wheeled harvester: The Silvatec Sleipner TH was a well constructed machine with adequate power and ergonomics to harvest timber on the trial site. This machine is fit for purpose especially when considering felling operations on sloping ground.
The BOSS, Bogie Optimisation Stabilising System hydraulic ram actuated system helped to maintain stability and traction when harvesting and moving on site. The operator had 20 years of experience in mechanised harvesting. The studied Tigercat has been a reliable machine hours use with adequate power and responsive ergonomic control systems. Operator access was good for cab entry and machine maintenance.
Visibility from the cab was less than optimum but still judged to be fit for purpose. The machine appeared to be of strong rugged construction. Standard outputs of 7. Technical Development measured whole tree volumes using inventory plots and end product using length and top diameter.
Tractor based mechanised harvesting in sweet chestnut coppice: Forestry Commission Project Report 40 Increasing the use of wood as fuel and the proportion of woodlands under management are both Forestry Commission objectives for Great Britain. Coppice woodlands are a common stand type in southeast England and a large proportion are undermanaged. Coppicing has historically been carried out using manual and motor manual methods. The use of a harvester presents an alternative to declining manual working.
A Valtra T tractor fitted with a roof-mounted crane and Keto 51 felling head was studied in neglected coppice stands. The sweet chestnut Castanea sativa stands had been coppiced 17 and 27 years previously. Three products were cut from the stands; 4 m woodchip poles, 7 foot firewood logs and 1. Machine costs and outputs for the older and younger stands were 2. The machine coped well with coppice working although a greater than normal number of chainsaw malfunctions were experienced due to the tendency for the densely packed stems to pinch the saw.
The delays associated with this lead to a suggestion of a greater allowance to be made for this. The conversion factor of 1. Windfarm non-commercial tree clearance: Forestry Commission Project Report 3 As part of clearance of crops for windfarm development, felling is to take place in a wide range of crops, many of which are likely to prove uneconomic. This work firstly characterises the crops to be cleared for windfarm construction and then discusses the effect of crop and site characteristics on harvesting and clearance choices.
Felling, site clearance and woody biomass handling options then are discussed, providing outline outputs and costs as a reference in future decision making. This diameter range is also most suitable for the construction of bamboo rafts, as used in the subsequent transport trials. The distance to the skidding trails was kept to a maximum of 20 m to eliminate further variations. The performance of labor in the felling and bucking process was as follows: In cases where a group of culms was entangled and had to be brought down together, the time was calculated as an average of such a group of culms.
The average culm harvested had a weight of Harvesting time per ton for a two-person team was minutes, or in other words, one person was able to harvest about 0. These costs for the felling and bunching operation are surprisingly high. The costs might be slightly lower in situations where whole fields may be harvested in clear-felling operations.
Manual transport of bamboo culms is presently the most common form of forwarding. This is mainly done for domestic consumption over distances of up to several kilometres. The optimal range for manual transport is between 50 and m. For commercial-scale operations, the maximum range considered economically viable would be around m for downhill transport. Due to the relatively high friction of long bamboo culms, manual transport is most suitable for this terrain condition.
For transport over level or uphill terrain, the acceptable range diminishes considerably. In spite of the extensive use of buffalo and cattle in agricultural operations and horseback transport by certain ethnic groups Hmong, Yao , animal traction has so far not been applied to forest harvesting operations in the project area.
Buffalo and cattle are mostly used in pairs, which makes them unsuitable for forestry operations along relatively narrow foot paths and skidding trails. The slow reaction capability makes these animals also very vulnerable to leg injuries during downhill skidding, where easy manoeuvrability is required.
Suitable logging harnesses for these types of draught animals could also not be identified immediately FAO It was therefore decided to concentrate further investigations on horse logging operations. Harnesses, self-locking skidding chains and ropes were imported from Europe. Skidding troughs were manufactured locally from 2-mm tin sheets with two different opening widths 80 and cm. Two horses the size of large ponies shoulder height of cm were trained by a traditional Hmong horse-keeper in bamboo logging, using the above equipment.
Time for loading the skidding trough shoe with 10—15 culms for each trip and tying the bundle with a self-locking chain required an average of 4 to 5 minutes. The mean load per trip was kg with a range of to kg. During the observation of 21 roundtrips, the self-locking chains failed in only one case.
The utilization of this kind of equipment was found to be indispensable, since it was not possible to tie bamboo culms with locally available material into bundles and drag them over larger distances without the slippage of individual culms leading to the loosening of the bundle. On steeper downhill sections, a second operator is required to apply tension to the load to prevent it from slipping into the rear legs of the horse or the feet of the front operator. Some preliminary trials to extract bamboo on steeper uphill terrain showed that the performance dropped dramatically.
Due to difficulties in introducing horses to ethnic groups without previous experiences in keeping such animals, and the limitations of horse logging in terms of maximum skidding distance and poor performance on steeper slopes, it was decided to explore additional skidding technologies.
The conversion of locally available 2-wheel tractors into a pedestrian operated skidding device was identified as the obvious alternative due to the following reasons:. A review of the literature on pedestrian-operated mini-skidders revealed the following data on their performance and operational costs see also Table A prototype of a mini-skidder is presently under construction at the Faculty of Mechanical Engineering, National University of Laos, Vientiane.
Field trials on the machine are expected to commence towards the end of The prototype uses a 14 hp Yanmar engine and gearbox. The undercarriage consists of six inch-diameter truck wheels and rubber belts with a circumference of 2 m, cut from used excavator or truck tyres of about 1. The mini-skidder will be designed in a way that the engine is interchangeable with the standard two wheel agricultural tractor and other local agricultural devices.
For safety reasons the operator will walk sideways in front of the skidder and control speed, direction and breaks via a handlebar. The skidder will have a clamp bank loading device allowing the dragging of stems or bamboo culms of up to 15 m in length. Based on the analysis of its Scandinavian counterpart models, the proposed mini-skidder is predicted to have the following performance rates:. For distances below 10 km, costs for transport by 2- or 4- wheel tractors with a load capacity of 1 to 1.
The use of bamboo rafts for transport on the Mekong river and its tributaries is common. Such rafts are typically constructed for the transport of culms themselves, whereas transport of other commodities on such rafts is rarely found with the exception of transporting tourists, in the north of Thailand. Rafts are normally built in the rivers from 40 to 60 culms, in a crosswise double layer arrangement, with a total bamboo weight of about kg.
Field trials on the Namtha River have revealed that bamboo rafts could be constructed easily with a width of about m and a length of m. These would be made with up to layers of bamboo culms which would result in individual raft panels of about culms weighing about 2. The construction time is approximately hours, involving a 3-man team. Such raft panels require two people for steering. Based on these observations, the costs for river transport of bamboo by raft can be estimated as follows in relation to transport distance.
Transport costs for bamboo by river rafting in relation to transport distances. Six hours are estimated on the first day of operation for the construction of the rafts by a 3- person team. Thereafter, rafting is done by a 2 person-team for a period of about 2 hours. The three methods of skidding operations are compared in Figure 1.
The following table presents the cost estimates for current manual practices, horse logging and the proposed mini-skidder. For each of the systems an annual operation time of days is assumed. This relatively low figure is due to two main factors: The table shows that costs for manual transport rises sharply, and would allow this method to be feasible for distances of up to m only, not withstanding considerations of ergonomic limitations for repeated applications of this method.
Horse logging would be economically feasible up to distances of about 2, m, whereas the proposed mini-skidders would have a viable range of about 3, m. With uphill skidding situations the performance of horse logging systems drops dramatically to distances of between 1, and 1, m. In view of this, it is recommended to focus initially on horse logging as a superior option for extracting bamboo on a commercial scale in the project areas. However, due to the limitations of this system to only slightly inclined downhill or level terrain conditions, and due to the presently questionable acceptance of keeping horses by some ethnic groups, the introduction of the proposed conversion of 2-wheel tractors into forest harvesting machinery should be followed further.
The preliminary results of these studies have noteworthy implications for forest management planning at the community and regional levels in Laos. In situations where forest harvesting is being considered on a larger scale the commercial level as opposed to domestic use only much more attention needs to be given to both the technical and financial viability of extraction methods. Developing road access and laying out skidding trails to the production forest areas under consideration has to become an essential element of forest planning within such development strategies.
If the economics of forest harvesting operations are not taken into account, forest resources are typically over-exploited in the immediate vicinity of roads and rivers, or under-utilized in areas with limited accessibility.
Interconnecting Forests, Science and People
The mission of the Harvesting and Transportation Engineering Research Group is. to provide support and information to forest scientists and others interested in. Various natural materials have hierarchical microscale and nanoscale structures that allow for directional water transport. Here we report an. Large and small scale harvesting systems and operations including harvesting, extraction, environmental protection, operator health and safety, and value.