A slip tongue log skidder used in the 19th and early 20th centuriesElements of a skidding harness
A skidder is any type of heavy vehicle used in a logging operation for pulling cut trees out of a forest in a process called "skidding", in which the logs are transported from the cutting site to a landing. There they are loaded onto trucks (or in times past, railroad cars or flumes), and sent to the mill. One exception is that in the early days of logging, when distances from the timberline to the mill were shorter, the landing stage was omitted altogether, and the "skidder" would have been used as the main road vehicle, in place of the trucks, railroad, or flume. Modern forms of skidders can pull trees with a cable and winch (cable skidder), just like the old steam donkeys, or with a hydraulic grapple either on boom (grapple skidder) or on the back of the frame (clambunk skidder).[clarification needed]
Early skidders were pulled by a team of oxen, horses or mules. The driver would straddle the cart over felled logs, where dangling tongs would be positioned to raise the end of the log off the ground. The team pulled the tongue forward, allowing the log to "skid" along between the rolling wheels. These were known as "slip-tongue wheels" Starting in the early 1920s, animals were gradually replaced by gasoline-powered crawlers, although some small operations continue to use horses. In other places, steel "arches" were used behind the crawlers. Similar in function to the slip-tongue wheels, arches were used to reduce friction by raising up one end of the load, which was dangled from a cable which in turn ran down the back of the arch, and was raised or lowered by the crawler's winch. Another piece similar to the arch was the "bummer", which was simply a small trailer to be towed behind a crawler, on top of which one end of the log load would rest.
Clyde Skidder at Marathon Logging Camp ~1921
The early mechanical skidders were steam powered. They traveled on railroads, known as "dummylines" and the felled trees were dragged or "skidded" to the railroad where they were later loaded onto rail cars. Some, such as the steam donkeys, were relatively simple but other mechanical skidders were more complex. The largest of these mechanical skidders was the Lidgerwood skidder, which not only brought logs to the landing from the cutting site, but loaded them onto railroad cars as well, making it both a skidder and loader. One popular brand was the Clyde Skidder, built by Clyde Ironworks in Duluth, Minnesota.[citation needed] The Clyde was capable of retrieving logs from four different points at the same time. Each cable, or lead, was approximately 1,000 feet (300m) in length. Once the logs were attached and a clearance signal was sent for retrieval, they could be skidded at a speed of 1,000 feet per minute (18km/h). In New Zealand cables were run five miles.[citation needed] Working conditions around these machines were very dangerous.[example needed]
Modern equivalents
Manual skidding in Brazil, 2008
Contemporary skidders are tracked or four wheel drivetractors with a diesel engine, winch and steel, funnel-shaped guards on the rear to protect their wheels. They have articulated steering and usually a small, adjustable, push-blade on the front. The operator/logger is protected from falling or flying debris (or parted cables, or rolling over) by a steel enclosure. They are one of the few logging machines that is capable of thinning or selective logging in larger timber.[citation needed] Forwarders can haul small short pieces out, however a skidder is one of the few options for taking out some trees while leaving others when thinning mature lumber.
The skidder can also be used for pulling tree stumps, pushing over small trees, and preliminary grading of a logging path known as a "skid road".
While wood is being yarded (pulled) by the skidder, tree particles and seeds are cultivated into the soil.[citation needed]
Skidder logging can be disadvantageous in thinning operations due to the damage caused to remaining trees as branches and trunks are dragged against them, tearing away the protective bark of living trees. Another ecological concern is the deep furrows in the topsoil sometimes made by skidders, especially when using tires with chains, which alter surface runoff patterns and increases the costs of forest rehabilitation and reforestation.
Versions
Logging arch
Logging arch on display at Kauri Museum in New Zealand
This section needs expansion. You can help by adding to it. (April 2021)
A device similar to a skip tongue log skidder except that it is made of steel, including the spokedwheels
On a cable skidder, the cable is reeled out and attached to a pull of cut timber, then the winch pulls the load toward the skidder. The winch or grapple holds the trees while the skidder drags them to a landing area. Cable skidders are more labor-intensive than grapple skidders because someone (the operator or a second person) must drag the winch line out to the logs and hook them up manually. Nowadays, cable skidders are less popular than in the past.[citation needed] These machines are most useful in areas where it is not possible to drive the machine close to the log (such as in steep hills).
Grapple skidders
Modern dual function grapple skidder
Grapple skidders use a loader crane boom with a hydraulicgrapple bucket to grab and lift the timber.
There are three types of 'fixed boom' grapple skidders. A single-function boom type has two hydraulic cylinders, only allowing the boom to lower in one position. Dual-function booms (as pictured) have four cylinders, which allows for adjusting the boom in two different places. The third type permits the grapple boom to be swung from side to side, allowing spread out trees to be grabbed at once.
In some areas, loggers have combined a hydraulic claw on the side with the blade of their grapple skidders, making it possible to pile logs in some cases. More common on cable skidders, this also permits hauling back bark and tops when returning from a landing area to fallen timber.
Clambunk skidders
Clambunk skidders are more of a middle ground between skidder and a forwarder. They have large free swiveling hydraulic jaws positioned on the back of the chassis that clamp the logs. They usually don't have self-loading capability and require feller buncher or other machine with loader arm.
Lumberjack is a mostly North American term for workers in the logging industry who perform the initial harvesting and transport of trees. The term usually refers to loggers in the era before 1945 in the United States, when trees were felled using hand tools and dragged by oxen to rivers.
A skid loader, skid-steer loader, SSL, or skidsteer is any of a class of compact heavy equipment with lift arms that can attach to a wide variety of buckets and other labor-saving tools or attachments.
A winch is a mechanical device that is used to pull in or let out or otherwise adjust the tension of a rope or wire rope.
Excavators are heavy construction equipment consisting of a boom, dipper, bucket and cab on a rotating platform known as the "house". The house sits atop an undercarriage with tracks or wheels. They are a natural progression from the steam shovels and often mistakenly called power shovels, as power shovels may have similar looking buckets. All movement and functions of a hydraulic excavator are accomplished through the use of hydraulic fluid, with hydraulic cylinders and hydraulic motors. Due to the linear actuation of hydraulic cylinders, their mode of operation is fundamentally different from cable-operated excavators, which use winches and steel ropes to accomplish the movements.
A crane is a type of machine, generally equipped with a hoist rope, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy objects and transporting them to other places. The device uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. Cranes are commonly employed in transportation for the loading and unloading of freight, in construction for the movement of materials, and in manufacturing for the assembling of heavy equipment.
A loader is a heavy equipment machine used in construction to move or load materials such as soil, rock, sand, demolition debris, etc. into or onto another type of machinery.
A harvester is a type of heavy forestry vehicle employed in cut-to-length logging operations for felling, delimbing and bucking trees. A forest harvester is typically employed together with a forwarder that hauls the logs to a roadside landing.
A steam shovel is a large steam-powered excavating machine designed for lifting and moving material such as rock and soil. It is the earliest type of power shovel or excavator. Steam shovels played a major role in public works in the 19th and early 20th century, being key to the construction of railroads and the Panama Canal. The development of simpler, cheaper diesel, gasoline and electric shovels caused steam shovels to fall out of favor in the 1930s.
A swing yarder is a mobile piece of heavy duty forestry equipment used for pulling logs from the woods to a logging road with cables. The swing yarder is also known as a grapple yarder.
A grapple is a hook or claw used to catch or hold something. A ship's anchor is a type of grapple, especially the "grapnel" anchor.
A steam donkey or donkey engine is a steam-powered winch once widely used in logging, mining, maritime, and other industrial applications.
A yarder is piece of logging equipment that uses a system of cables to pull or fly logs from the stump to a collection point. It generally consists of an engine, drums, and spar, but has a range of configurations and variations, such as the swing yarder.
Cable logging, also referred to as skyline logging, is a logging method primarily used on the West Coast of North America with yarder, loaders, and grapple yarders, but also in Europe.
The Washington Winch sits in the forests of eastern Victoria near Swifts Creek and is also known as the Washington Iron Works Skidder.
A tank transporter is a combination of a heavy tractor unit or a ballast tractor and a mating full trailer, hydraulic modular trailer or semi-trailer, used for transporting tanks and other armoured fighting vehicles. Some also function as tank recovery vehicles, the tractors of which may be armoured for protection in combat conditions.
Collier Memorial State Park is a state park in southern Oregon. The park is operated and maintained by the Oregon Parks and Recreation Department. It is located on U.S. Highway 97, approximately 30 miles (48 km) north of Klamath Falls and 105 miles (169 km) south of Bend. The park covers 146 acres (59 ha) along the Williamson River.
Dog-hole ports were the small, rural ports on the West Coast of the United States between Central California and Southern Oregon that operated between the mid-1800s until the 1930s. They were commonly called dog-holes because the schooners that served them would have to be able to "turn around in a harbor barely small enough for a dog".
A logging truck or timber lorry is a large truck used to carry logs. Some have integrated flatbeds, some are discrete tractor units, and some are configured to spread a load between the tractor unit and a dollied trailer pulled behind it. Often more than one trailer is attached.
The Hume-Bennett Lumber Company was a logging operation in the Sequoia National Forest in the late 19th and early 20th centuries. The company and its predecessors were known for building the world's longest log flume and the first multiple-arch hydroelectric dam. However, the company also engaged in destructive clearcutting logging practices, cutting down 8,000 giant sequoias in Converse Basin in a decade-long event that has been described as "the greatest orgy of destructive lumbering in the history of the world."
The Sugar Pine Lumber Company was an early 20th century logging operation and railroad in the Sierra Nevada. Unable to secure water rights to build a log flume, the company operated the “crookedest railroad ever built." They later developed the Minarets-type locomotive, the largest and most powerful saddle tank locomotive ever made. The company was also a pioneer in the electrification of logging where newly plentiful hydroelectric power replaced the widespread use of steam engines.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
