A forwarder is a forestry vehicle used to gather, load, and carry pre-cut logs to a loading area for larger trucks to haul. It is a six- to eight-wheel articulated all-wheel drive machine equipped with a hydraulic loader and timber grapple to load the logs onto its trailer, or bunk.

Available from a number of manufacturers in a variety of sizes, the forwarder is classified by its loading capacity. Typically it is capable of carrying six to 18 tons.^[1] It is a diesel-powered vehicle with hydrostatic transmission. However, Volvo announced the development of a hybrid forwarder, running on both electrical and diesel power, in 2007.

Contents 1 History 1.1 Technology Advancements 1.1.1 Hybrid Forwarders 2 Features/How it Works 3 Common Manufacturers 4 References

[edit] History

Forwarding, also known as prehauling, is the process of transporting logs from the stump to the landing area for hauling. In the early 1960s researchers attempted to get a clearer time estimate on the transportion process. They decided to separate time spent in the woods versus time on the road. All hauling from the stump to landing would be known as “prior to hauling or prehauling.”^[2]

Initially, this process was carried out by single axle short wheelbase trucks, known as Bob-tail trucks. Often the terrain or weather was too difficult for the Bob-tail trucks to traverse so prehauling was done with homemade carts or buggies pulled by small crawler tractors or medium-sized farm tractors. Then came the introduction of pallets.

A pallet was a heavy-duty, U-shaped holding unit made from pipe. These pallets were hand-loaded in the woods and hauled to an area where they would be loaded on to larger trucks with specially made pallet beds.

A full pallet was extremely heavy, making it difficult to transport from the woods to the road. Originally they were placed on sleds and dragged, or skidded, by crawler tractors. In the mid-1950s, they began using surplus military trucks with tilting flatbeds to hold the pallets. These all-wheel drive vehicles could carry a much larger load and the tilting flatbed made them much easier to unload onto the landing area.

Eventually, the military vehicles were replaced by wheeled tiltbed trailers with mounted cable-loaders. The trailers were towed by either tracked or wheeled tractors. This lead to the development of the Harrison-Brown Pulp-wood Harvester, which combined the trailer and tractor into a more integrated unit. Steering was achieved with opposing hydraulic cylinders attached to both units. Also mounted to the trailer was a modified backhoe arm equipped with a small grapple to load the pallet.

The first four-wheel drive, fully integrated forwarders appeared in Canada.

[edit] Technology Advancements

[edit] Hybrid Forwarders

Hybrid technology does not only decrease fuel consumption, but can also lessen a machine’s ecological footprint by cutting carbon dioxide production as much as 50 percent.^[3]

In this effort Volvo manufactured the El-Forest forwarder, the first piece of hybrid forestry machinery. 

Volvo Technology Transfer AB became involved in hybrid technology by acquiring part of the El-Forest company, based in Örnsköldsvik, Sweden, who was already busy designing the new forwarder.

The El-Forest forwarder utilizes hybrid technology in conjunction with a diesel-powered generator. All of the wheels are equipped with 23 kW traction motors and are designed to follow the same wheel track with adapted speed. It is much smaller than the average forwarder, (9.5 tons compared to 14.5 tons), but is capable of hauling the same load (12 tons).^[4] Its lightweight frame and wheel design also helps to lessen damage to the environment.

Sweden’s largest forest owner, Sveaskog, purchased the first El-Forest forwarder. It is to be delivered to them in 2008. The Sveaskog company manages some 11 million acres (4.5 million ha) of land, including 8.4 million acres (3.4 million ha) of productive forest land.

[edit] Features/How it Works

A forwarder is a six- to eight- wheel articulated machine that picks up and loads pre-cut logs with a hydraulically powered articulating boom and grapple.

The forwarder drives around the woods collecting logs and storing them in its holder, known as a bunk, on the rear section of the machine. Those logs are then brought forward to a loading area where they will are loaded onto larger trucks for shipping.

Standard features include diesel engine, bunk, loader with grapple, and tires. It is also available with options for air conditioning, tracked tires, and hydrostatic drive.

[edit] Common Manufacturers

• Bell
• Brandt
• Caterpillar
• Eco Log
• Fabtek
• Franklin
• John Deere
• Komatsu
• Ponsse
• Ranger
• Rottne
• Tigercat
• Timberjack
• Valmet

[edit] References

1. ↑ Forwarders. Forestry Gov. UK. 2008-09-24.
2. ↑ Stenzel, George; et al. Logging and Pulpwood Production. Wiley-Interscience: 1985. 223.
3. ↑ Even Forestry Machinery is Going Hybird. Green Car Guide. 2008-09-24.
4. ↑ Volvo Invests. Green Car Congress. 2008-09-24.