Felling
Trees should be felled using a notch and back cut. Felling notches and back cuts must be made high enough above ground level to enable the chain-saw operator to begin the cut safely, control the saw, and have freedom of movement for escape. A number of notch configurations can be used for felling trees, including an open-face notch, a conventional notch, and a Humboldt notch. In the past, a 45-degree notch was commonly used. However, an open-face notch of 70 degrees or more allows the hinge to...
Estimation of Height
It is important for tree workers to be able to estimate the height of the tree and thus its position when figure 7.6 Mechanical advantage can be added to the pull line by using a block and tackle. felled . Accurate height estimation will help avoid hitting obstacles. Remember that the height of the felling cut will affect the distance that the top of the tree reaches when it is felled. Most techniques for height estimation are based upon a geometric principle of similar right triangles. There...
Safety 1
OSHA OHSA in Canada ANSI Z133.1 Canadian Standards Association CSA approved shall should response system job briefing work plan resuscitation CPR emergency response aerial rescue electrical conductor direct contact indirect contact leglock method Working in and around trees can be a very hazardous profession if proper care and safety measures are not followed. Safety must always be the first concern. Safety is more than using special equipment, wearing appropriate gear, or attending occasional...
Pruning Tools
When pruning trees, it is important to have the right tool for the job. When doing fine pruning, with cuts less than V2 inch in diameter, hand pruners secateurs can be used. The scissor-type hand pruners, with a bypass blade configuration, are preferred over the anvil type. They make cleaner, more accurate cuts. The bypass blade configuration is also preferred figure 5.1 Hand pruning shears secateurs work best with two bypass blades. Avoid the blade and anvil design, which can damage stem...
Valddtain tresse Vt
Probably the most commonly used of the variations of the French Prusik Tied with a length of cord eye-and-eye split-tail , which is smaller in diameter than the line on which it is tied Holds securely and releases easily Also used in rigging applications Essentially an asymmetric Prusik hitch Holds securely but can bind Neither as fluid nor as temperamental as a French Prusik
Ropes and Knots
Rope maybe considered the arborist's most important tool. The characteristics of a rope strength, stretch, durability, etc. are the result of the materials and techniques used to make it. To date, polyester is the material most widely used by arborists, and most commercially available climbing and rigging lines are made from this fiber. Nylon has high strength, stretch, and energy absorption but tends to lose strength when wet. Natural fibers are not generally as strong as the new, synthetic...
Tying In
The choice of where to tie in is very important. Generally, it is desirable to pick a high, central location in the tree. This allows freedom of movement and easy access to most points in the tree. The higher the tie-in figure 4.19 The higher the tie-in point, the farther the climber can move out on the limbs. It is easiest to work when tied in directly above the working area. It is very important not to tie in to a crotch that would allow a swing toward power lines in the event of a slip or...
References
Adams, Mark. 2004. An overview of climbing hitches. ArboristNews 13 5 29-35. Adams, Mark. 2005. Son of a hitch A genealogy of arborists' climbing hitches. Arborist News 14 2 51 55. American National Standards Institute. 2000. American National Standard for Tree Care Operations Tree, Shrub, and Other Woody Plant Maintenance Standard Practices Support Systems a. Cabling, Bracing, and Guying A300, Part 3 . Tree Care Industry Association, Manchester, NH. 29 pp. American National Standards...
Role of the Ground Worker
Ground workers are an essential part of a rigging operation they set up friction devices, run lines, detach ropes, and send equipment and lines up to the climber. Safety is dependent on good communication between the climber and the ground workers. The landing zone drop zone is the area beneath the tree where pieces are to be dropped or lowered. There must be a clear and efficient means of communication between climbers and ground workers so that each knows when it is safe for a ground worker...
Pruning Cuts
Each pruning cut should be made carefully at the correct location, leaving a smooth surface with no jagged edges or torn bark. When a tree sheds a branch naturally, it is typically shed back to its point of origin the trunk or a larger branch . Inside this branch union is a branch protection zone, which helps protect the remaining stem from decay. The correct location for a cut that removes a branch back to its point of origin sometimes called a thinning cut is just beyond the branch collar. It...
Sample Test Questions Shx
1. A type of knot used to secure a rope to an object, another rope, or the standing part of the same rope is 2. A common, easy-to-untie knot for forming a loop is 3. Which of the following is an advantage of the Blake's hitch over the tautline hitch c. it doesn't roll out although a stopper knot is still recommended A. personal protective equipment B. weighted cord used to set rope D. fungal fruiting body, sign of decay E. bringing injured climber down G. used for secured footlocking H. tied in...
Hardware and Tools
It is important to select the appropriate hardware for cabling a tree. Cables, eye bolts, and other cabling hardware come in various sizes and types. Consider the size of the limbs, the weight to be supported, and the presence of decay when choosing materials. If the hardware is too small or inadequate, the cable may fail. figure 8.2 Common-grade, 7-strand cable. figure 8.2 Common-grade, 7-strand cable. Two types of cable are commonly used in cabling trees, common-grade, 7-strand, galvanized...
Equipment
Choosing the correct equipment for a given situation can make the job safer and much more productive, provided the science behind a given device is understood. New equipment seems to come on the market every day. Some of this equipment has been adapted from other industries, and some has been designed for arborist uses. Arborists demand a great deal from the equipment used in rigging, so using appropriate equipment within its design limitations is imperative. Arborists need to understand the...
TrueFalse Qcw
1. T F Shock-loading results when ropes are used to stop heavy limbs in motion or free fall. 2. T F The greater distance a limb drops before its motion is stopped, the greater the load on the 3. T F The use of knots increases the working-load limit of a rope. 4. T F Dividing the published tensile strength of a rope or piece of equipment by the design factor yields the working-load limit WLL . 5. T F Tensile strength is determined under a steady load. 6. T F Dynamic loads damage ropes and other...
Forces in Rigging
Arborists are only beginning to investigate and understand the forces in rigging. It is clear that removing large, heavy sections of trees using ropes and other equipment generates large forces. These forces are greatly affected by the equipment and techniques employed. The size and weight of the piece removed is the base factor in determining the force involved, but forces are also affected by the distance of fall, the type and amount of rope in the system, and the angles involved. By...
Limbing and Bucking
After the tree has been felled, it must be sawed up, using a process called limbing and bucking. Limbing is the process of cutting off all of the side or lateral branches of the tree. Cutting up the main logs and trunk is called bucking. Of course, all chain-saw safety principles apply when limbing and bucking, but some additional safety principles should also be remembered. First, if more than one worker is working on the tree, extra care should be taken. The cuts that one worker makes can...
Introduction Igi
In arboriculture, rigging is the use of ropes and other equipment to take down trees or remove limbs. Rigging is often associated with removals, but the procedures can be very important in pruning operations. Rigging is necessary when it is not possible to free fall or drop tree sections due to potential hazards, obstacles below, or power lines. When removing limbs from a tree that is being trimmed, care must be taken not to damage the remaining branches, trunk, and root system. Rigging...
Cable Installation
Before installing cables in a tree, the tree should be pruned as needed. Hazardous limbs should be removed. If necessary, the tree should be pruned for balance and to reduce excessive weight. A general rule of thumb is to install the cable at least two-thirds the distance from the weak junction to the ends of the limbs. Exact placement will depend upon the location of lateral branches and defects. The branches at the point of cable attachment must be large enough and solid enough to provide...
Pruning to Establish Good Structure
A good structure of scaffold branches should be established while the tree is young. Scaffold branches provide the primary framework of the mature tree. Properly trained young trees will develop into trees figure 5.16 Trees should be pruned when young to establish a strong scaffold system like the tree on the left. The tree on the right will become more prone to failure as it matures. with a strong structure and will require less corrective pruning as they mature. In addition, young trees can...
Tree Health and Sciences
growth rings sap wood heartwood vascular system Trees have several basic needs, including sunlight, air, water, essential minerals, and adequate growing space above and below ground. When all of these fundamental needs are fulfilled, a tree can survive, grow, and flourish. If any of these is lacking, the tree will suffer and perhaps die. Tree climbers should understand the fundamental principles of tree biology to better understand tree health and the stress factors that affect it. vascular...
Ascent
When the tree, site, and climbing gear have been inspected and deemed to be safe, the climber can plan a climbing strategy. There are many ways of getting into and ascending a tree. The climber can use the climbing line, a ladder, or climbing spurs if the tree is to be removed . Each method has advantages and limitations. A climber must be tied in or otherwise secured while entering or working in a tree. One tech- figure 4.9 A second worker should always support the ladder while a climber...
Basic Rigging Techniques
Knowledge and experience will improve a climbers arsenal of rigging techniques. As learning progresses, a climber will come to understand more of the variables to be considered. It is important for novice riggers to be introduced to the thought processes involved in planning a rigging operation. What are the limitations of the tree and site What equipment and techniques will be employed Skill in planning for different options comes with experience and can make rigging operations safer and more...