Heavy equipment machinery

The power of hydraulics is critical in boosting the productivity of tree harvesting equipment.

Tree harvesting has come a long way from two lumberjacks standing at opposite ends of a gigantic saw, using brute strength to cut through the trunk. Hydraulic technology plays a huge role in today’s forestry equipment, thanks to its combination of power density and reliability.

TimberPro Inc., Shawano, Wis., manufactures a variety of mobile equipment used for moving logs from the forest to a landing area, where they can be picked up by logging trucks. TimberPro’s TF 830 forwarder is also used in other applications, where cutting attachments are fitted on the machine for the actual harvesting of trees. TF 830s are also being used in:

•     lumber mill yards — unloading trucks, sorting logs, and transferring logs from the log yard to the mill

•     the pipeline industry — laying out and picking up material for equipment to drive on, picking up and laying bridging for the pipe to lay on before installation in the trench

•     forest fire applications — fitted with water tanks and nozzles

TimberPro’s machines are designed with 360° continuous rotation cabs, allowing the operator to always face the work, whether over the front, back, or side of the machine. According to Jeff Huntington, the company’s engineering support manager, "Our machines are more robust and a lot more stable than much of the competition’s. This allows us to handle larger attachments and larger loads."

Getting started
Huntington notes, "The forwarders use many hydraulic controlled functions. An open-loop implement valve system controls the cab rotation through a small Bosch Rexroth hydraulic motor and gearbox. It also controls all the cylinders for main boom (up/down), stick boom (in/out), telescopic boom (in/out), steering, and grapple (open/ close and rotate). The closed-loop wheel drive is a hydrostatic system, consisting of a Rexroth pump and two Rexroth motors connected to a two-speed gearbox."

Operation of the machines is fairly straightforward — the operator uses electronic joysticks, handles with control buttons, switches, and an electronic foot control to send signals to an onboard IQAN system, developed by Parker Hannifin Corp., Cleveland. IQAN is an electrohydraulic management system that monitors operator inputs and converts these data to a usable electronic signal to control hydraulic valve and hydrostatic drive functions.

IQAN also communicates with other systems, including the machine’s 300-hp Cummins diesel engine and multiple temperature and speed sensors. A Master Display Module (MDM) is connected to other control modules using CAN communication. The MDM displays data from these systems and also allows control of them. After receiving input from sensors and control input from the operator, IQAN sends out control signals to the proportional coils located on a Rexroth wheel-drive pump and Parker/VOAC control valves.

The closed-loop wheel drive system operates at 6000 psi. It includes a variable-displacement, reversible pump and dual variable-displacement hydraulic motors, all from Bosch Rexroth. The dual motors are attached to a two-speed transfer case that is connected to the front and rear axles through drive shafts. The transfer case reduces the speed of the hydraulic motors by two different ratios, depending on whether the operator has the gearbox shifted into high or low.

The implement system is openloop, with a working pressure of 4000 psi and maximum flow of 95 gpm. It contains a variable-displacement, load-sensing pump connected to a Parker/VOAC multi-section, load-sensing, pressure-compensated, directional control valve system. The valve sections communicate to the implement pump to demand needed pressure and flow through a load-sensing circuit. Both the pump and valve need this load-sensing feature to communicate together. The implement pump’s swash plate angle is changed and only produces the needed pressure and flow that the valve asks for.

New design brings rave reviews
A recent redesign boasts many improvements over older versions of the forwarders. Troubleshooting has been improved by the use of a rear gull wing door with ladder. This offers mechanics a safe place to stand while working on the machine, and also opens up the entire hydraulic and engine compartments for easier access.

Thanks to the use of electronic engines and J1939 CAN communication to the IQAN control system, the machines can now display any errors, problems, or even fuel usage of the engine to the operator. The operator’s cab was also improved for comfort by decreasing noise levels by 15 dB, locating all operator controls in short reach of the operator’s hands, and adding an air-suspended operator’s seat.

Problem solved
After finishing the machine, one major task was fitting the extra hydraulic hoses used when certain attachments were installed. The much smaller envelope used in the new design created man high-wear points on the hoses. Engineers solved this by moving the implement valve stack to a better location and changing how hoses were routed. Steel tube lines with hoses connected on each end were used in areas that were tight on space.

Huntington commented that one major benefit in the new design is a huge improvement in hydraulic cooling capabilities. "Cooling is a big problem with a lot of forestry machines, and because of location and size of a new oil cooler, this problem was solved."

http://www.hydraulicspneumatics.com/200/IndZone/ForestryLumber/Article/False/13466/IndZone-ForestryLumber

A forwarder is a 6 or 8 wheel articulated machine used to
transport logs, which have been cut to prescribed lengths,
from the forest floor to a stacking area along side the forest
road, ready for uplift by timber lorries. It is all wheel drive
and is equipped with a hydraulic loader and timber grapple,
which is used to load logs into the machine’s trailer, known
as a bunk.

Forwarders come in a range of sizes and are classified by their
load carrying capacity, which typically varies from 6 tonnes to
18 tonnes. They are powered by diesel engines and the transm-
-issions are generally hydrostatic, controlled by the machine’s
on board computer. The operator sits in a robust air-conditioned
cab, which is constructed to provide protection should the
machine roll over or be hit by a falling tree.

A single machine is capable of hauling up to 50,000 tonnes
of timber per year. The majority of forwarders are manufact-
-ured in Scandinavia.Mechanical Engineering Services provides
and maintains 45 forwarders in use throughout the Forestry
Commission. It has been providing this service since the
inception of mechanised harvesting 30 years ago. In so
doing it has amassed a wealth of knowledge and expertise
in themaintenance and repair of these technically advanced
machines.If you require forwarder maintenance or repair,
contact your local Mechanical Engineering Services workshops.
Disposal of both owned and leased forwarders alsofalls within
Mechanical Engineering Services‘ remit. This is done through
regular advertisingin the trade press and tender sales conducted
three times each year at Chapelhall Workshop.

http://www.forestry.gov.uk/forestry/INFD-6EXL2W

Timbco Hydraulics
The Timbco TF800 Series hydroskidder forwarder has a 20ton capacity and is powered by a 260hp engine with hydrostatic drive. The biggest advantage, the company says, is the high capacity loader with continuous swing. Being able to work over the front is another big advantage when working on rough ground, repairing skid trails or loading trucks. A number of tires are available for use in a wide (10′10") configuration, a narrow (9′7") configuration, or as duals for swamp skidding. The same basic machine is now being used as a clam bunk skidder, arch grapple skidder or fellerbuncher with either a processing head or disc saw. It has also been used for yarding and pipe laying. As well, it has been used for cutting and skidding with one machine, the company says.

Rocan/Rottne
Two new forwarder models from Rottne include the Solid F9 eight wheel drive thinning forwarder and the Solid F12 forwarder for select cutting. The F12 is suitable for all types of logging operations, with its narrow construction and tracking features making it superior in tech2.jpg (2757 bytes)narrow and dense thinning stands, the company says. Powered by a John Deere 6068 TF 150 water-cooled turbo engine, the F12 has two articulated steering joints, one in midpoint and one at the rear bogie. Powered by a John Deere 4045 TF 250, the F9’s flexible transmission, eight wheels, small dimensions and low ground pressure make it ideal for an undamaged stand after thinning, the company says. Both machines have a knuckleboom loader with fixed tower, a swing base with dual slew cylinders, a 1.4 metre extension and endless rotator. The F9 has a Rottne 28 grapple, while the F12 has a Rottne G35 grapple. The Rottne 16T eight or sixwheeldrive forwarders now come with a 185hp John Deere engine and have 20 per cent faster working hydraulics, says the company. The 12T Rapid six or eightwheeldrive forwarders are now powered by a 125hp John Deere engine.

TransGesco
TransGesco offers two forwarder models. The six wheel drive TG206 shortwood forwarder is powered by a 275hp engine and has 120,000 lbs of drawbar pull, while the eight wheel drive TG88C is powered by a 350hp engine and offers a huge 160,000 lbs of drawbar pull. The 58,000lb TG206 has a ground clearance of 30 inches and a lift capacity of 5,500 lbs at 20 feet, while the 66,000lb TG88C has a lift capacity of 6,300 lbs at 20 feet. Both models feature a large, 25ton payload, 100 per cent hydrostatic drive computer controlled traction with a hydraulic motor mounted on a planetary gear reduction, and low ground pressure with a track shoe choice up to 1.5 metres wide. The machines’ loaders are equipped with a telescopic stick with a 26-foot reach and a wood basket designed to maximize payload for various log lengths up to 35 feet. The TransGesco forwarders are also available in clam bunk or grapple skidder configurations.

Fabtek
Fabtek manufactures a line of six forwarders, including four, six and eight wheel drive units. The models include the FT 344B, the FT 344LB, the FT 346B, the FT 544C, the FT 546C and the FT 548C and range in weight from 24,500 to 34,500 lbs. With load capacities ranging from 16,000 to 32,000 lbs, the forwarders feature electric power shift transmissions, full load, high reach booms and full 40degree turning articulation. The rack and pinion four cylinder loader swing system features fully proportional controls with high torque and high swing speed, the company says. A rear mount loader is standard on all models. The boom geometry is designed for maximum utility and the top mounted stick boom cylinder stays clear of obstructions. All Fabtek forwarders feature large, high visibility cabs, hydraulic tilt for complete under cab system access, heavy steel plate engine and radiator coverings, vibration isolated attach points and John Deere components.

Allied Systems/Ranger
Allied Systems has added Ranger forwarders to its line of forestry equipment. The result of years of development and product acquisitions, the machines’ design features include 180 degree swivel operator’s seat with dual controls-the steering wheel in front and two joysticks in the rear to control steering and the loader. Built on the same concept as the Ranger skidder, the new Ranger F410A and F614A forwarders are four or six wheeled machines with a 10 to 14ton payload. Other features include a rugged skidder based chassis, a Cranab 650XL loader with 22.6′ reach, a 360 grapple with GV12S rotator and a Cummins 6BT 5.9 152 hp turbocharged engine. Heavy-duty Clark 32,000 three speed power shift transmissions and Clark 36R locking differentials are standard. Pressurized cabs have factory-installed air conditioning and heating and skylights for better visibility.


Partek/Valmet
The new North American Valmet 840 and 860 forwarder series set high standards for power, dependability and value in the mid and large forwarder class, says the company. Each model features a new cab design with excellent visibility. The digital hydrostatic transmission control DTCII provides superior maneuverability. Each model has a new portal gear bogie to provide more inside ground clearance and greater bogie swing, making longer and faster cycles possible. The six and eight wheel models carry 12 and 15.5ton payloads respectively and come standard with Cranab loaders and grapples to handle fast clean up.


Rotobec
Powered by a Cummins 4BTA3.9 diesel engine providing 116 hp at 2500 rpm, the Rotobec F2000B forwarder is fully hydrostatic and has a load capacity of 4.5 tons. The absence of a drive shaft allows a large steering angle of 53 degrees, while an ergonomic cab provides excellent visibility and a swivel seat provides operator comfort. Electric proportional control offers increased handling ability. A tilt cab facilitates access for service and maintenance. The F2000B is equipped with the Rotobec 40F continuous rotation loader with a curved boom design that allows the loader to work in front of the machine without risk of collision with the machine’s cab. It has a main boom lift capacity of 2,000 lbs at 18′. Specifically designed for the F2000B, the Rotobec continuous rotation grapple model 6760 opens to 66" and has a single actuation cylinder.

Franklin Equipment
Franklin transmissions and loaders and Cummins engines are featured on the three forwarders in Franklin Equipment’s lineup. The 670 Bogie PML is powered by a 152hp, six-cylinder 6BT5.9 engine and, with standard equipment, weighs nearly 37,000 lbs. It features a P4376 four-speed hydrostatic power shift transmission and a maximum torque of 1600 rpm. The 28,000lb H70 Bogie PML has a hydrostatic variable displacement transmission, a maximum torque of 1600 rpm and is powered by the 152hp, six-cylinder 6BT5.9 engine. The 632 Bogie is powered by a 116 hp, four cylinder Cummins 4BTA3.9 after cooled engine and has a maximum torque of 1500 rpm. With a P4376 four speed power shift transmission, the machine weighs nearly 25,000 lbs. All three machines feature Franklin 4600 Magnum post mounted loaders with a 20ft boom and 1/5 cord continuous rotation bypass bucket with three-pump hydraulic system. Among other features common to all three machines are hydraulic quick steering, deluxe reverse operator controls, hydraulic dozer blades, shock mounted engine and radiator, and swivel suspension seats. Optional on the 632 Bogie is a Franklin 4600 top mounted loader with a 20foot boom. Four inch steering cylinders are optional on all three forwarders.

Caterpillar
The new Caterpillar 554 and 574 forwarders are designed to meet the requirements of cut to length harvesting. With a three speed power shift transmission and incorporating a 14metricton payload, the 574 is powered by a 163hp Cat 3126 engine, comes equipped with front powered hydraulic bogie lift and has a tiltable loader to boost productivity on slopes and improve access to logs. Each bogie is controlled by a separate hydraulic cylinder for individual movement on each side of the forwarder. The three-knuckleboom loaders available for the 574 have reaches ranging from 23.6′ to 32.8′. With a 10metricton payload, the 554 has a 122hp Cat 3054 engine and a two speed hydrostatic power shift transmission. Bogie lift is optional on the 554. The four-knuckleboom loaders available for the 554 have reaches ranging from 21.3′ to 28.5′. Both models offer eight wheel drive for optimum traction and have direct injected, turbocharged and after cooled engines.

Timberjack
With a maximum load rating of more than 37,000 lbs, the 1710B forwarder from Timberjack is ideal for high volume, long haul operations. Powered by a 215hp Cummins diesel engine, it comes in either a six or eight wheel version and has unique balanced bogie for load stability. The new 1410B forwarder offers a 167 hp Cummins diesel engine that develops high torque at low rpms for maximum tractive effort. Rated at nearly 31,000 lbs of load capacity, it is also available in six or eight wheel versions. The new 1110 forwarder from Timberjack is an eight wheel drive machine that can transport a 12ton payload. The exclusive loader control system (LCS) controls the hydraulic flow to match the demands of all crane functions, allowing quick adjustment to suit conditions. Hydrostatic mechanical power transmission and load sensing hydraulics make for smooth starts and inching, while the unique bogie inside the rim design gives good ground clearance. The new 610 forwarder is ideal for smaller operations. The four-wheel drive model is powered by a 100hp Cummins four cylinder diesel engine and uses the same crane found on the larger 1010B forwarder. Standard is a heavy-duty decking blade. The 10ton capacity, 110hp 1010B is available in six and four wheel versions and comes with LCS for setting operator preferences.

Ponsse
The largest forwarder in the Ponsse range, the Buffalo S16, has been redesigned with a lower hood, significantly reducing noise inside and outside the cab. As well, changes in the power transmission have improved tractive force by six per cent, the company says. A larger power transmission pump has raised the efficiency of the hydrostatics, thus improving the durability of the hydraulic system. The gearing of the bogie axles has been made slower, improving the control properties. With a 210hp, six-cylinder Cat diesel engine, the 34,500 lb S16 offers either conventional controls or minigrips and has a 14ton load bearing capacity. The K75 crane has a reach of more than 30 feet. The 26,000lb Caribou S10 is equipped with a four cylinder, 122 hp Perkins diesel engine, a hydrostatic drive train and a new, durable K70 crane, also with a reach of more than 30 feet. The eight wheel forwarder has a load bearing capacity exceeding 10 tons. Ponsse’s 30,000lb Bison S15 also features the K75 crane, with a 360 degree turning angle, and a six cylinder 159hp Perkins diesel engine. The six-wheel machine has a 12ton load bearing capacity and planetary gear bogie axles. The new tightenable frame joint is made of cast material and reduces joint wear, while a 44degree steering angle makes the machine very nimble, the company says. The rear frame is made of two sections, making it possible to vary the length of the load area as required.

http://www.forestnet.com/archives/april_00/techupdate.htm

Basically, forwarder is a specially equipped tractor which is used to haul logs from woodland to depot.

These tractors have a compact trailer and crane unit for loading the logs onboard.

Usually forwarders don’t have front wheels in the same sense as farm tractors do. Instead, pivot steering is used (the trailer is coupled to the tractor by means of a "hinge" and strong hydraulic cylinders steer the tractor).

Modern forwarders have automatic transmission, air-conditioning and power-steering. They are powered by strong turbo-charged diesel engines and they can carry very heavy loads of timber in most difficult terrains, too.

http://www.taimetsoi.fi/uutiset/what_is_a_forwarder.htm

The Tigercat 1065 is a heavy-duty 18-tonne forwarder.
The 1065 forwarder has strong frames, large pins and steer cylinders and a durable center section with tapered roller bearings in the articulation and oscillation joints.

Designed with the operator in mind, the cab is spacious with excellent all-around visibility. Access to the engine, driveline and hydraulic components is superior to all competing forwarders.

    Benefits

• 255 hp (190 kW) Mercedes 906 Tier III engine.
• Durable construction for tough applications.
• Electronic canbus control technology to govern machine functions.
• Excellent stability when loading on uneven terrain. The unique center section design eliminates the need for an oscillation lock.
• Extra large cab with extended windows for improved visibility when unloading.
• Designed for extreme duty with 18 tonne rated bogie axles.
• All control valves are located in a single compartment accessible at ground level.
• Excellent access to engine and hydraulic components.

http://www.tigercat.com/1065.htm