It is always sad to see any tree removed as they are all a vital part of our ecosystem and our very existence. However when a tree does need to be removed, whether it is diseased, dangerous, or has simply out grown its position, it is important that it is removed in the safest way possible to avoid injury to people or damage to property. Any form of tree work should be carried out by an operative who has the qualifications and insurance to do so.
The approach to removing a tree will be different in each circumstance depending upon its location, structural integrity and growth habit.
If a tree is growing in an open space with good access, the most straight forward way to remove it is to fell it in its entirety from the base of the stem. A number of different felling cuts can be used depending on the direction the tree needs to fall, the angle of the lean and the size of the tree stem. A pull rope or winch can be attached to the top of the stem if the tree is leaning in the wrong direction or if the wind is compromising the direction of fall. Wedges can also be used to aid felling, which would be hammered into the back cut of the tree until the tree starts to fall.
Once the tree has been felled, the branches would then be cut away from the main stem and dragged to the chipper where they are then processed into woodchip. The main stem would then be cut into manageable sections and removed from site.
When the tree cannot be felled in one due to space or location, it can be removed by a process known as a sectional dismantle. This would involve a climber accessing the canopy of the tree using a rope and harness and removing the tree, branch by branch, using either a hand saw or a chainsaw. The branches would be dropped to the ground below, where the grounds-person would then drag the branches to the chipper where they would be processed into woodchip. The climber would then cut the upright stem into manageable sections by using climbing spikes. The sections of timber would then be dropped to the ground below.
When the tree is located above obstacles such as greenhouses, buildings, or flowerbeds where the drop zone is limited, a rigging system is used to lower branches to the ground in a controlled manner. The process still involves a climber accessing the tree using a rope and harness but this time a pulley block is also attached to the canopy, where a rigging rope will pass through. The climber will attach the rigging rope to each branch. The grounds-person will then hold the other end of the rope from the ground and lower each section down slowly after it has been cut by the climber. This avoids any damage and also enables large trees to be taken down in small spaces. The larger stem sections will be removed in a similar way, being attached to the rope and pulley block. For heavier sections of wood, the rope will also be passed through a friction device attached to the base of the tree to help the grounds-person control the timber slowly to the ground.
Sometimes trees can be structurally compromised either by storm damage, decay or disease which can render the tree unsafe to climb. The natural growth habit of a tree can also affect the feasibility of climbing using a rope and harness if a suitable anchor point cannot be established to work from. In these instances a mobile platform can be used to access the canopy without having to climb the tree. Mobile platforms/cherry pickers come in the form of tracked machines, towed machines or free moving wheeled machines varying in height from 20ft to upwards of 150ft. Some of the smaller machines are able to fit through a standard garden gate in order to get them into position beneath the tree. However access can often be a problem when using bigger machines and in some cases it is not possible to get the machine into position.
On larger scale tree removals a crane is used to aid the removal process. This can be as a result of structural issues with the tree or simply because the process of removal could be a lot quicker and more straight forward with a crane rather than climbing the tree. In these instances the climber and crane operator work closely together to remove large sections of the tree simultaneously.
The climber will access the tree either attached to the crane cable or by climbing the tree from the base. Once the climber has established a suitable anchor point in the tree they will signal the crane to lower the cable into position. The climber will then attached the crane cable using a series of chains. The tension is then assumed by the crane operator whilst the climber makes the cuts using a chainsaw. The section is then lifted and lowered to the ground to the groundsmen. The same process is then repeated until the entire tree has been removed to ground level.
Access for a crane is often restricted on many jobs therefore this option is not always possible.