Heli-logging
Encyclopedia
Heli-Logging, or Helicopter Logging, is a method of logging that uses helicopter
s to remove cut tree
s from forest
s by lifting them on cables attached to a helicopter. Helicopter logging
is often used in inaccessible areas of forests. Because the use of helicopters reduces the level of infrastructure required to log in a specific location, the method also helps to reduce the environmental impact of logging. It also can increase the productivity in these remote areas.
In 1998, the inventor supervised the building of an experimental grapple which was to be operated by a K-Max Lift Truck helicopter. However, because the K-Max had no hydraulics, it was necessary to design and install an externally mounted, jettisonable sled
carrying a hydraulic power pack, to operate the grapple.
Initial flight trials were carried out using the external hook and wire rope configuration on the 25th of April 1998. In late October 1998, a successful full scale harvesting trial using a grapple
designed by the inventor and funded by the timber licencee was carried out at Lunchtime Lake on Vancouver Island.
Press releases and logging industry recognition followed. Patent applications in the United States
and Canada
were submitted and granted in 2001 and 2002 respectively.
. The trees are selected based on demand for specific types and grades. Before the selection process is complete the selected trees are bored to check their reliability. The selected trees are then marked and their diameters are recorded. The diameter of the tree is measured at 1.3 meters above the ground. The sizes of the trees that are selected are controlled by two things. The minimum size is controlled by the economy while the maximum size is controlled by the capacity of the helicopter. Once the trees are selected they are climbed, the limbs are removed and the trees are topped
. The length of the tree and the diameter at its top are then recorded. All the recorded data is then entered into a database
which calculates volumes, weights, etc. The selected trees are then partially cut at the stem and supported by wooden wedges. The stem is then grappled by the helicopter and pulled until the wood breaks at the partial cut. The logged trees are then brought by helicopter to a predetermined roadside location or dropped into open water where they are collected.
Helicopters remove the branches and trunks as soon as they are cut. Because of this roads do not need to be built to the site were the logging is taking place. Fewer roads are built in the process and less heavy equipment is moved through the forest.
Research by Roberts, Ward and Rollerson done in 2004 shows that post-logging landslides are more common after conventional cable-based logging than heli-logging. Landslide rates following conventional logging are one and a half times more common than landslide rates following heli-logging.
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...
s to remove cut tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s from forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
s by lifting them on cables attached to a helicopter. Helicopter logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
is often used in inaccessible areas of forests. Because the use of helicopters reduces the level of infrastructure required to log in a specific location, the method also helps to reduce the environmental impact of logging. It also can increase the productivity in these remote areas.
History
Standing Stem Harvesting, a selective harvesting method within Heli Logging, was invented by Philip Jarman of Port Alberni, British Columbia between May and October 1997. The initial harvesting equipment used wire rope or chokers to rig the stem and a modified external hook to engage the choker and lift the stem clear of the stump. In this way the process of harvesting, which includes climbing , measuring, cutting, rigging, and lifting was pioneered by a single pilot flying a light utility helicopter.In 1998, the inventor supervised the building of an experimental grapple which was to be operated by a K-Max Lift Truck helicopter. However, because the K-Max had no hydraulics, it was necessary to design and install an externally mounted, jettisonable sled
Sled
A sled, sledge, or sleigh is a land vehicle with a smooth underside or possessing a separate body supported by two or more smooth, relatively narrow, longitudinal runners that travels by sliding across a surface. Most sleds are used on surfaces with low friction, such as snow or ice. In some cases,...
carrying a hydraulic power pack, to operate the grapple.
Initial flight trials were carried out using the external hook and wire rope configuration on the 25th of April 1998. In late October 1998, a successful full scale harvesting trial using a grapple
Grapple (tool)
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 throwing grapple is a multi-pronged hook that is tied to a rope and thrown to catch a grip, as on a parapet or branch of a tree...
designed by the inventor and funded by the timber licencee was carried out at Lunchtime Lake on Vancouver Island.
Press releases and logging industry recognition followed. Patent applications in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
were submitted and granted in 2001 and 2002 respectively.
Process
Heli-Logging is also known as standing stem harvesting which is based on individual tree selection (ITS). The selection process is done by engineers and surveyorsSurveying
See Also: Public Land Survey SystemSurveying or land surveying is the technique, profession, and science of accurately determining the terrestrial or three-dimensional position of points and the distances and angles between them...
. The trees are selected based on demand for specific types and grades. Before the selection process is complete the selected trees are bored to check their reliability. The selected trees are then marked and their diameters are recorded. The diameter of the tree is measured at 1.3 meters above the ground. The sizes of the trees that are selected are controlled by two things. The minimum size is controlled by the economy while the maximum size is controlled by the capacity of the helicopter. Once the trees are selected they are climbed, the limbs are removed and the trees are topped
Tree topping
Tree topping is the practice of removing whole tops of trees or large branches and/or trunks from the tops of trees, leaving stubs or lateral branches that are too small to assume the role of a terminal leader. Other common names for the practice include hat-racking, heading, rounding over, and...
. The length of the tree and the diameter at its top are then recorded. All the recorded data is then entered into a database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
which calculates volumes, weights, etc. The selected trees are then partially cut at the stem and supported by wooden wedges. The stem is then grappled by the helicopter and pulled until the wood breaks at the partial cut. The logged trees are then brought by helicopter to a predetermined roadside location or dropped into open water where they are collected.
Advantages
Conventional logging allows the stems to fall. On rocky terrains this often results in damage to the stems that makes them unusable. On steep terrains falling trees can slide downhill and become irretrievable. Heli-logging allows logging to take place in more remote places. It also allows certain trees to be logged that previously could not be due to their proximity to a structure or pipeline. These issues make conventional logging less efficient than heli-logging. Logging using helicopters is safer than conventional logging. Falling trees are dangerous for the loggers as well as for surrounding structures or utilities. Heli-logging also extends the logging season. This is due to the lack of snow load on a standing stem.Helicopters remove the branches and trunks as soon as they are cut. Because of this roads do not need to be built to the site were the logging is taking place. Fewer roads are built in the process and less heavy equipment is moved through the forest.
Research by Roberts, Ward and Rollerson done in 2004 shows that post-logging landslides are more common after conventional cable-based logging than heli-logging. Landslide rates following conventional logging are one and a half times more common than landslide rates following heli-logging.