Timber Extraction and Transportation

Harvested Timbers   Once timber is felled, the logs will be moved to a landing so that they can be picked up and transported. Landings are cleared areas used to hold timbers until they can be transported. Forests being logged commercially will have a carefully planned network of roads specially for the purpose of moving the timber to landings.

The timbers will be moved from the location where they were felled with the use of wheeled or tracked tractors called “skidders” which are used on level terrain. Skidding involves raising one end of the logs from the ground and dragging them. This may be done by hooking steel cables to each timber log or by gathering several together with the skidder’s hydraulic arms and dragging the whole bunch of wood to the landing site.

  Timbers in the Water

The extraction of timber in land with steep or uneven terrain is often done with another type of heavy equipment called a “yarder.” In some cases, wheeled vehicles called “forwarders” may be used. For timber extraction and in logging areas that are particularly remote, aircraft such as helicopters have been used to extract logs. From the landing, the timber will be loaded onto trucks for transportation to a lumber mill for wood processing

Debarking of Timbers

When the trucks arrive at the mill, the wood they carry will be unloaded with mechanical unloading cranes and placed in piles called “log decks.” The nature of log decks is largely dependent on the region in which the sawmill is located. In some places the timbers are stored in a circle around the unloading crane in others they are stored in lines.

The unloading cranes are capable of grabbing an entire truckload of timbers at a time. The log piles are sprayed with water on regular basis otherwise the wood will become brittle and split. When the timber is to be processed into lumber, it will be picked up by the cranes and placed on a conveyor to be carried into the mill for debarking and bucking. Some mills prefer to take logs that have already been bucked whereas others do the job themselves. The bark is removed using one of three different types of equipment such as drum debarkers, rosser head debarkers and ring debarkers. 

Drum debarkers tumble several logs at a time so that the bark is worn away by the other logs and by the drum itself. The drum method is most often used when debarking smaller logs. The rosser head method of wood debarking involves spinning the timber while a cutter passes along it lengthwise to remove the bark. This is the preferred method for debarking hardwood trees. The ring debarker is used for removing bark from softwood timbers and works by passing the log though a ring of grinder blades. 

  House Timbers