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Technology UpdateHarvesting and Felling Heads
Tech Update Editor: Mel-Lynda Andersen
The HSG-140 and HSG-160 single grip harvesters from Hahn are designed for plantation thinning and select cut operations. Capable of felling, delimbing, measuring and bucking, they are full-featured units, reports Hahn, offering fingertip processing controls, electronic length measuring sys-tem, 3/4" pitch felling/bucking saw, two-speed roller feed and automatic saw oiler. Working with small excavators or with rubber- tired carriers, the HSG-series single grip harvesters are two of the safest, most economical and most efficient ways to harvest small timber, claims the manufacturer.
The LogMax 3000 features a frame designed to absorb and deflect stress concentrations. All shafts are nitrogen-hardened and mounted in hard bronze bushings. A hydraulically operated link arm with free float function is fixed to the rotator. In upright position, the head hangs almost vertically and leans 13° down towards the knives when downtilted. The press force of the feed rollers can be hydraulically and mechanically adjusted to the trees diameter. The roller arms have a hydraulic spring to minimize losses of pulling force and stress of material. The delimbing unit features four movable knives with patented "positioning" to minimize friction losses, and the knives have a wide cutting edge to handle thick branches. The head is fitted with a hydraulically driven chainsaw with pressure-controlled feed force and flow-controlled feed speed. This head is sold and serviced in the west by Kamloops, BC-based Pierce/LogMax and in the east by Rocan Forestry Service Ltd. of New Brunswick.
The EGS 600, manufactured by Rottne and available through Rocan Forestry BC Limited, is a one-grip harvester for final thinning and final felling. The head is a compact unit with all equipment built in and protected under covers. The head is mounted in a hydraulically controlled pendulum arm. A rotator attachment allows felling in any direction.
A strong clamping arm, together with casted delimbing knives and inclined feeding wheels, fixes the stem in position for felling, delimbing and cutting. During feeding the pressures are reduced, proportional to the tree diameter, on the clamping arm and knives, making it possible to perform faultless delimbing with-out an unnecessary reduction of feeding power says Rocan. The unit has three movable and one fixed delimbing knives.
Valmet manufactures a variety of harvesting heads, including the 945, 960 and 965 series. With Valmet heads, the stem is supported by feed rollers, rather than by the limbing knives. The feed rollers are in turn suspended on cam curves, which vary the inclination of the rollers in relation to the diameter of the log, enabling the heads to hold thicker, heavier logs in place without having to clamp the log by hydraulic means. The stem ends up in the same position every time, which is a pre-requisite for exact length and diameter measurement and the basis for correct volume recording, maintains the company. All Valmet heads have five delimbing knives, each one computer-designed to give maximum enclosure of the stem regardless of the dimension of the log. The fifth knife is movable, enabling the heads to limb curved stems with accurate results. The design of the saw box allows the heads to handle stems with different shapes and leave a low stump height. The 945 S-2 is a light, efficient thinning head; the Valmet 960 S-2 is a versatile single-grip harvester head dimensioned for big trees and thinning operations; and the 965 S-2 is a single-grip head designed for final felling.
Caterpillar now offers four models of CTL harvesting heads that complement the new line of Cat wheeled carriers, as well as Cats track-type carriers. The harvesting heads are designed to handle tasks ranging from first thinning to final felling. All four harvesting head models use a patented feeding mechanism that keeps the feed rollers centred on the stem as the diameter changes. Simultaneously, the feed roller pressure varies to ensure maximum grip without damaging the stem. Other features include fixed delimbing knives attached to the tilt frame, movable knives made from heat-treated steel and hydraulically con-trolled for adjusting to the natural contour of the tree, diameter measurements received and encoded by a computer-aided bucking sys-tem via single or dual sensors located with-in the base of each delimbing knife, a heat-treated steel frame supported by dual hydraulic cylinders, solid rubber feed rollers wrapped in chains, an independent hydraulic arm on the measuring wheel for accurate length measurements, and a high-speed saw-bar equipped with a .404 chain operating at 148'/sec. Two of the Cat harvesting heads offer a computer system designed for accurate bucking and measuring as well as keeping a production database. The heads, manufactured in Soderhamn, Sweden, can be matched to different types of machines and harvesting conditions.
The strength and durability of Woodking harvester/processing heads has been tested in extreme conditions, while harvesting and processing trees in the flooded reservoirs of western Canada. The company reports production of 10 to 12 cubic meters/hour at depths of more than 80 feet.
The Woodking 400, a lightweight harvesting head, is engineered for dense stands of small-diameter trees. The Woodking 400 has angled delimbing knives and 255cc feed motors that can deliver quality delimbing at a speed of more than 16.5' per second.
The Woodking 550 features an increased cutting capacity of 22" with a choice of two high-torque feed motors, designed specifically for short tree-length or CTL operations. This attachment can be specially adapted for older commercial thinnings or coupled with a feller buncher.
The Woodking 650 is a mid-range single- grip head with a 26" maximum cut-ting capacity, enhanced by special angled feed roller arms that hug the wood to provide increased processing power on bigger trees. It is designed with feller bunchers or harvesters running with conventional grapple skidders, forwarders or yarders in mind. The Woodking 850 cuts trees with flared butts and can handle heavy logs or old-growth trees.
The FT 240 dangle-style 24" processor head is the newest addition to Fabteks line of processing heads. Features include delimb arms of high-tensile steel with 200 brinell hardness, standard 21" steel spike rolls (rubber rolls with chains optional), specialized hydraulics which interface with open-or closed-centre systems, advanced digital ramped roller speed control for smoother, more accurate measurement, reduced system stress and longer hose life, and an independent measurement encoder sensor. Drive motors can be custom tailored to match the carriers hydraulic supply.
Fabteks four-roll Series 2000 18" processor head is the companys newest controlled feller processor. Replacing both the 16" and 18" older units, this new system uses multiple encoder measurement sensors for the most accurate measurement yet, says Fabtek. The patent-pending auto chain tensioning system and simplified piston oiler are now standard, offering longer bar and chain life and faster cuts. The Series 2000 13" processor head delivers economical CTL processing.
Working in both hardwood and softwood forests, Waratah harvesting heads can be installed without modification to the carriers standard boom and stick by means of a 330° rotator. The Waratah HTH Rotator provides both a lifting capacity and pushing capacity of 60,000 lbs. The new Waratah heads use larger feed rolls for maximum speed and increased traction on the log. Three live feed rollers, one on each grab arm and one fixed in the body of the frame, come together in a triangular configuration ensuring maximum traction and alignment of the tree. The Waratah angled drive arm design provides maxi-mum control of the smaller stems, pre-venting damage to smaller tops. The HTH delimb arms are equipped with front and back replaceable knives constructed with a hardening treatment for prolonged sharp-ness and durability in abrasive wood conditions. The new HTH delimb arms are also longer for easier access into piled or decked wood, while maintaining a superior shape and curvature. A 16" topping saw maximizes more fibre and saves production time. A.404 Hultdins saw unit, complete with automatic chain tensioner and cam-style lubrication, is standard on HTH 20T, 20TR, 20 and 22 Warrior. A heavier 11BC 3/4-pitch saw unit with a larger displacement saw motor is standard on the HTH 24 Super and 26 Bigwood.
All Loewen forestry products are built with common, easily accessible parts, and can adapt to most PSI and GPM requirements. Such standard components include a Rexroth saw motor, DanFoss heavy-duty hydraulic motors, Loewen saw disk, Koehring Timberjack saw disk and Quadco saw disk. Features include 22" cutting capacity, high-speed saw disk felling head, complete with high or continuous rotation wrist assembly, two-arm collecting capacity that enables the operator to quickly collect small trees and keep them standing straight and tight for placement in neat bunches, easy access to all well-guarded hoses, motors and cylinders, and a 104" 5,800-lb. sawhead. The high-rotation wrist offers more versatility and productivity, reports Loewen, which adds standing trees and wind-fell trees can be cut and placed in bunches at any angles with less carrier movement.
SPECS AT A GLANCE
The Ponsse H73 has been manufactured to handle heavy, large-dimensioned stems with thick limbs. Weighing only 1,000 kg, it can efficiently handle trunks of up to 70 cm in diameter. It has a feed force of 26 kN and its three feed rollers guarantee a strong grip. The H73 delimbs trunks efficiently with its five delimbing knives without damaging the bark. The three-point grip provides accurate measurement of stem diameters. The length-measuring roller is located at the centre of the harvester head, facilitating an unchanging grip after the stem has been cut.
The Ponsse H53 is a multi-purpose head for trees less than 50 cm in diameter. The Ponsse H60 is a mid-size multi-purpose harvester head suitable for both final felling and thinning.
The Patu line of harvester heads from Finland includes the 405 RH and the 505 RH, as well as the 400 SH and the 550 SH. The Patu 405 RH can be installed on a farm tractor and can be used with a crane; the pump unit for the harvester head is mounted on the three-point hitch. The Patu 505 RH is used for both thinnings and clear cuts, and can be mounted on prime movers from about 10 tonnes. Patu heads feature a unique guide chainsaw: the 405 RH has a 10cc saw motor, where-as the motor on the 505 RH is 19cc. The design of Patus harvesting heads is very compact; the saw, the measuring roller and the cylinders are serviced from below.
The double jaws of the Patu 400 SH enable a firm, gentle grip on the stem with little resulting bark damage, and its narrow design makes it easy to get the head between trees, thus making it particularly suitable for thinnings. Thanks to the location of the knives the butt end of the stem can be delimbed, with the very lowest limbs cut. It can also pick stems from a pile, making it an efficient processor to work with a skidder or a skyline.
Gilbert-Tech manufactures a full line of felling heads, including the 1252, 1255 and 1249. Five years ago, Gilbert-Tech introduced its full later-al tilt system, which has revolutionalized conventional felling, claims the manufacturer. The use of this fully lateral tilting system accentuates the felling head manoeuvrability, speeds up the process of tree felling while permitting more respect for the environment. It is now possible to bunch the tree trunks in such a ay as to minimize the displacement of the feller buncher, skidder or transporter. Gilbert-Tech has made a number of improvements to its 220° side tilt system for 1999, including new oil gear lubrification tank in the balancing frame, new compensated flow cross-over relief and new fixation plage and gear, with no weld assembling.
Features of Lakos line of harvesting heads include strong compact head chassis, parallel gripping geometry of the main wheel arms to ensure positive feeding, front knives operated by one hydraulic cylinder, tilt frame construction powered by a large hydraulic cylinder, load-sensing, high-performance cut- ting and felling capacity, proportional pressure controls of wheel and delimbing arms according to tree diameter, rubber mountings to reduce risk of structural breakage, dual and cross-diameter measuring mechanism positioned on the main wheel arms, and a spring-loaded length-measuring device with combined idler wheel. The Lako 450 is meant for commercial thinnings and for attachment to purpose-built forest machines and small excavators. The 550 has been developed for thinnings and final fellings of small and medium-sized timber. The 650 is built for final fellings and late thinnings in harsh conditions.
Davco Machine Ltd.
Davco Machine Ltd. of Grande Prairie, AB, manufactures the TP 1000 Tree Harvester which fells, limbs and cuts to length. With a fixed mount, the operator has full control of the tree. This unit weighs 1,100 lbs., with a capacity of up to 12". Other features include four presets on the computerized measuring system, track drives on the tree, and .404 harvester chain. The CC 1200 is 57" high, 42" wide with a cutting capacity of 14". It features a spring-loaded accumulator arm and a saw with 36" diameter high-speed 1-5/8" kerf and rotatable square teeth.
Machinatech Inc. manufactures the Mach-tech 3655, a feller buncher saw head with a 360° side-tilt system driven by a planetary gear. The planetary is somewhat similar to a carriers track planetary, explains the company. It provides suffient torque output for the manipulation and rotation of both the head and its load of trees, and its setting within the frame ensures protection against shocks. The head affords better visibility of ground and potential obstacles, says Machinatech. Both clamp arms and accumulator arms are mounted with the cylinder attached to both arms for improved holding power, and a synchronized bar on each pair of arms provides simultaneous closing or opening of each set. The Mach-Tech 3655 has a simplified, well protected tilt system with only two main components: the planetary gear and its hydraulic motor, explains the manufacturer. The Mach-Saw disc is fully machined and has no welding. It is equipped with 24 staggered teeth.
The Rolly Series single-grip roll drive harvester from Risley Equipment fells, delimbs, processes and tops at the stump. The single-grip harvester/double-grip processor is assembled around a rugged central frame structure, and theres a choice of modular components to meet individual harvesting applications. The Rotosaw high-torque, intermittent circular cutting blade is designed so the harvester can also operate as a feller buncher. A mounting bracket with side tilt and wrist action enables the Rolly II to handle a range of hardwood or softwood logging applications. It is available with Risleys exclusive FibreSaver drive rolls. The Risley Attachment Management System (RAMS) provides accurate measuring with diagnostic capabilities.
The Rotobec RSG250 single-grip harvester features a reduced number of hydraulic hoses (three) and electrical wires (only four conductors required) between the porter and the harvester. The hydraulic control is strategically located to minimize maintenance and maximize hose and component protection. Other features include two hydrostatically driven metallic rollers, 6,300-lb. feeding power, one fixed, one floating and four mobile delimbing knives, hydrostatic drive and 25-1/2" maximum diameter.
Hytec harvester heads models are available with capacities ranging from 12" to 33". Features include automatic tension on upper jaws to accommodate diameter differences during processing, hydraulic components enclosed for protection, one-minute trouble-shooting inspection panels, lockout on roller and stroke when saw is not in full retractor position, auto bar retract, and 11H floating saw head or .404 with automatic chain tensioning. These heads are compatible with all boom-operated feller-type carriers and are available with 120° or 340° tilt.
The DHT550 harvester/processors robust construction and 16" topping saw permit cross-cutting of the forks found on deciduous trees. The topping saw also increases productivity of other cross-cutting operations, resulting in higher-quality logs from small tree tops, says Denharco. Photocells are integrated into the harvester structure, and the measuring wheel is controlled by a hydraulic system that results in better con-tact with the stem, greater speed and unmatched measuring precision, according to the company. The Denharco SH500 has four moving and two fixed wrap-around knives and spiked feed rollers or optional rubber tires. The SH500 features programmable computerized control and measuring systems with diameter measuring and trouble shooting. The SH600 features tri-angular positioning of the feed roller mounting, ensuring greater feed force; protected valve package; wide measuring wheels that accurately grip the stem; and reversible rubber feed rollers.
The Keto 525 features soft-touch track frame design with longer footprint, progressive grip-start and release, plastic wear pads, modified pivoting point and stronger linkages. The soft-touch tracks feature 32- mm rollers, minimized fibre damage cleats and longer tracks. Cylinder pin locks have been redesigned, the saw swing has increased bolt strength in the bearing housing, a guard plate has been added on the bottom side for improved valve protection, and a suction valve has been added to the saw motor. The Keto 525 also comes with an optional topping saw. The Arbro stroke harvester weighs 250 kg and has a maxi-mum cutting and delimbing diameter of 12", with a stroke length of 32" and a 14" sawbar. Other features include a 210° turning radius, Volvo saw motor and micro-processor- controlled measuring unit.
AFM offers four harvesting heads: the AFM 45 Corona, the AFM 55 Husky, the AFM 60 and the AFM 80 Magnum. The new 45 Corona is intended for thinnings and smaller sized clearcuttings. It can be installed on light wheel-based carriers or small excavators. The 55 Husky is designed for thinnings and clear-cutting operations with trees of approximately 55 cm. It has a three-motor power feed unit combined with an automatic pressure adjusting system, and it is equipped with four delimbing knives. The 60-series unit can fell and delimb stems between five and 60 cm in diameter. The 80 Magnum can handle trees up to 90 cm, and is equipped with the Opticut system, in which the saw bar is always turning to optimal cutting angle and distance in relation to the diameter of timber
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©1996-2007 Logging and Sawmilling
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