Many types of tools are used to maintain overhead electrical distribution systems. Sometimes the maintenance can be accomplished with the use of an aerial lift or line maintenance truck; however, access to a telephone pole with a truck may be difficult, or there may not be a truck available. When a truck is unavailable, personal climbing equipment becomes necessary. Climbing poles is not difficult if care is taken to select, fit, and maintain climbing and rigging equipment. In this chapter, you will learn about climbing and rigging tools and their uses. You will also learn how to select and fit the climbing or rigging tool for the job and provide the proper care of the climbing and rigging tools to keep them in good working condition.
When you have completed this chapter, you will be able to do the following:
Climbing tools consist of body belts, safety straps, climbers, gloves, and a hardhat. Climbing tools are used for scaling poles and trees, erecting power lines, and support for clearing and topping trees.
The lineman’s body belt is made up of four parts: a cushion or pad section for comfort and support, a belt with a tongue and buckle, a tool saddle, and D-rings attached to the cushion. Two measurements are necessary for fitting the body belt. One is used to determine the D-ring position on the belt and the other to actually fit the belt to your body. The most critical measurement of a body belt, in terms of comfort, is the “D” measurement. The proper “D” size is normally found by measuring from the prominent part of one hip around the back to the same point on the other hip bone. Add 2 inches to this measurement, so the D-ring heels will be just forward of the hip bones rather than on them. The measurement to properly size the body belt is determined by measuring completely around the waist where the belt is worn. All measuring is over the work clothing to be worn under the belt. Refer to the figure below for distances.
Workers must use their safety straps at all times upon reaching a work position on any pole, tower, or structure. Before workers transfer their weight to the safety strap, they should ensure that the snaps on the safety strap are fastened properly to the D-ring of the lineman’s body belt. The only safe way to determine that the snap is securely fastened to the D-ring is to actually look at the D-ring each time you fasten the snap. Never depend upon the sound or feel of the snap. Leaning back for a test can also be dangerous because the snap may be caught in something other than the D-ring.
Climbers are used for ascending, descending, and maintaining work positions on the pole. They consist of leg irons with straps, pads, and gaffs. The leg irons are adjustable from 14 to 20 inches in half-inch increments. The gaffs are attached to the leg iron and are normally replaceable. Adjust the leg iron to a position 1 inch below the prominent inside bone of the knee. Secure the climber to your leg and foot with adjustable leather or Velcro straps.
Wear gloves to protect your hands. Use gloves whenever you are required to handle rough, scaly, or splintered objects, such as a wooden pole. Gloves should fit snugly, but not tightly. They should be flexible enough to allow for easy movement of the hand when you are working or handling tools.
A hardhat protects your head from falling objects and accidental contact with electrical circuits . It is made up of a shell and a suspension system. Adjust the headband portion of the suspension system to fit around the crown of your head. Adjust the chinstrap, which is attached to the shell, to fit beneath the chin. Adjust both the headband and the chinstrap to fit comfortably. DO NOT overtighten. Electrical workers must wear insulating hardhats rated as class E, electrical type. Class E hardhats are rated to meet a test of 20,000 volts 60 Hertz (Hz) for 3 minutes with 9 milliamps (MA) maximum leakage. Hardhat requirements are found in the 29 Code of Federal Regulations (CFR) Article 1926.100 and American National Standards Institute (ANSI) Z89.1-2014.
Body Belt. Inspect of the body belt before use. Inspect all leather parts for tears, cracks, and cuts. Inspect the stitching for rotting and broken threads. Inspect the D-rings and rivets for rust, breaks, and cracks.
Safety Strap. Inspect your strap before each use and every 6 months if stored for a period of time. Like the body belt, safety straps should be inspected for tears, cracks, and cuts. Also inspect the stitching for rotting and broken thread and the buckle for rust, breaks, and cracks. If you discover any of these things on the strap, it should be taken out of service. If you have any doubt about the serviceability of the strap, discard it.
Climbers. Inspect climbers before each use. Inspect straps and pads frequently for cuts, loose stitching, enlarged eyelet holes, and tears; and inspect buckles for rust and damage. Inspect gaffs for burrs, and ensure they are sharp.
Gloves. Inspect gloves for holes and cuts. Also inspect the stitching for rotting and broken threads. If there is any doubt about the serviceability of the gloves, replace them.
Hardhat. Inspect the hardhat shell for dirt, cracks, and burns. Check the suspension system for cuts and the chinstrap for elasticity and fraying before use. Replace the hardhat immediately if there are any signs of wear, damage, abuse, or environmental degradation.
The following steps describe how to properly use climbing tools to ascend and descend a utility pole safely.
Before climbing, ensure your arms are protected by rolling down your shirtsleeves. Protect your hands with leather gloves.
If you follow these simple procedures, you will not have any problems ascending the pole.
Use the following guidelines when working with climbing tools:
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You will use rigging tools during the installation, maintenance, and removal of assorted equipment. This equipment, if used as intended, will enable you to perform your work safely, quickly, and easily. Without the proper knowledge of rigging tools, you would need to lift heavy objects by hand and climb up and down the pole every time you needed additional tools or materials. For example, the block and tackle is the tool of choice when you need to manually lift and position heavy equipment and support material, such as crossarms and distribution transformers, to the top of a utility pole; whereas, the hand line allows utility workers working at the top of a pole to raise smaller equipment components, hardware, or tools with little effort. Because these tools are essential to the safe movement of equipment that can be heavy and awkward, it is essential to maintain and inspect them on a regular basis. The correct and timely maintenance of these items will ensure their long life and reliability. Incorrect maintenance can lead to their failure, which could result in equipment damage or injury to yourself or your co-workers.
The hand line is the simplest rigging tool that you will use in the field. In its simplest form, it is just a rope used to raise and lower relatively lightweight tools and equipment. There are basically two types of hand lines: single and continuous. A single hand line is nothing more than a single piece of rope with each end braided so the ends will not unravel. Using this hand line requires the individual to do all the raising and lowering of equipment needed. The hand line is normally used when no other type of lifting capability is available.
Whenever the load exceeds the limits of a hand line, use a block and tackle. It will allow you to lift the object safely and with little effort. A block and tackle arrangement is a combination of blocks and ropes by which an object or load can be lifted or moved in a desired direction. Blocks are designated by the length of the shell in inches and by the number of sheaves. Blocks with one, two, three, or four sheaves are called single, double, triple, and quadruple blocks, respectively. The size of the sheave and the depth of the groove in the sheave usually determine the largest size rope for any block. Frames of the blocks can be made of wood, metal, or a combination of both.
During the course of a career, you may need to hoist or move heavy objects. Wire rope is used for heavy-duty work. In the following paragraphs, we will discuss the characteristics, construction, and usage of many types of wire rope as well as the safe working load, use of attachments and fittings, and procedures for the care and handling of wire rope.
Wire rope consists of three parts: wires, strands, and core. In the manufacturing of wire rope, a number of wires are laid together to form the strand. Then a number of strands are laid together around a core to form the wire rope.
The basic unit of wire-rope construction is the individual wire, which can be made of steel, iron, or other metal in various sizes. The number of wires to a strand will vary, depending on the purpose for which the wire rope is intended. Wire rope is designated by the number of strands per rope and the number of wires per strand. Thus, a 1/2-inch, 6 by 19 wire rope will have 6 strands with 19 wires per strand; but it will have the same outside diameter as a 1/2-inch, 6 by 37 wire rope, which will have 6 strands with 37 wires of much smaller size per strand.
Wire rope that is made up of a large number of small wires is flexible. The small wires are, however, easily broken, so the wire rope does not resist external abrasion. Wire rope that is made up of a smaller number of larger wires is more resistant to external abrasion but is less flexible.
The core is the element around which the strands are laid to form the wire rope. The core can be of hard fiber, such as manila, hemp, plastic, paper, or sisal, or it can be made of wire strand. Each type of core serves the same basic purpose: to support the strands laid around it.
A fiber core offers the advantage of increased flexibility. Also, it serves as a cushion to reduce the effects of sudden strain and acts as a reservoir for the oil to lubricate the wires and strands to reduce friction between them. Wire rope with a fiber core is used in places where flexibility of the wire rope is important.
A wire-strand core not only resists heat better than a fiber core, but it also adds about 15 percent to the strength of the wire rope. On the other hand, the wire strand makes the wire rope less flexible than a fiber core would.
An independent wire-rope core is a separate wire rope over which the main strands of the wire rope are laid. It usually consists of six seven-wire strands laid around either a fiber core or a wire-strand core. The core strengthens the wire rope more, provides support against crushing, and supplies maximum resistance to heat. Wire rope can be made by either of two methods. If the strands or wires are shaped to conform to the curvature of the finished wire rope before laying up, the wire rope is termed preformed. If they are not shaped before fabrication, the wire rope is termed non-preformed. When cut, preformed wire rope tends not to unlay, and it is more flexible than nonpreformed wire rope. With nonpreformed wire rope, twisting produces a stress in the wires; and, when it is cut or broken, the stress causes the strands to unlay. In nonpreformed wire rope, unlaying is rapid and almost instantaneous, which could cause serious injury to someone not familiar with it.
Common types of wire rope include 6, 7, 12, 19, 24, or 37 wires in each strand. Usually, the wire rope has six strands laid around a fiber or steel center.
Figure 1 — Two types of wire rope.
Two other common types of wire rope, 6 by 19 and 6 by 37 wire rope, are shown in Figure 1. The 6 by 19 type of wire rope (Figure 1A), having 6 strands with 19 wires in each strand, is commonly used for rough hoisting and skidding work where abrasion is likely to occur. The 6 by 37 wire rope (Figure 1B), having 6 strands with 37 wires in each strand, is the most flexible of the standard 6-strand wire ropes. For that reason, it is particularly suitable when you are going to use small sheaves and drums, such as those used on cranes and similar machinery.
Chain hoists come in a variety of designs and rated lifting capacities. They are made of steel or aluminum alloy and range from 1/2- to 12-ton lifting capacities. While rigging, you will use hand chain hoists that are generally rated at 1 1/2 to 3 tons.
You will use these hoists in support of various maintenance and construction applications. The chain hoist shown here is typical of what you will use in the career field. It is designed to easily lift or move heavy weights and for applying tension to utility pole guying systems.
The chain hoist consists of a hoist mechanism, two hooks, a ratchet lever, a selector lever, and a handwheel. The hooks generally have a safety snap so that the load cannot accidentally come off the hook. The selector lever is used to select up or down movement. The handwheel is used to quickly take up the slack in the chain before actual lifting begins. Hand chain hoists have been designed with built-in safety features that indicate when a hoist has exceeded its safe working capacity. If you use a hoist in a manner that exceeds its rated design limit, the hooks or the ratchet lever will begin to bend. This bending signals impending failure. Because of the damage that will be done to the hoist, it is important to ensure that you never exceed the lifting capacity.
Hooks and shackles (Figure 2) provide a useful means of moving loads without tying directly to the object with a line, wire rope, or chain. Attach them to wire rope, fiber line, blocks, or chains. Use shackles for loads too heavy for hooks to handle.
Figure 2 — Hooks and shackles.
Inspect hooks at the beginning of each workday and before lifting a full rated load. Inspect the areas of a hook, illustrated in Figure 3, for wear and strain. Be especially careful during the inspection to look for cracks in the saddle section and at the neck of the hook.
Figure 3 — Hook inspection
When the load is too heavy for you to use a hook, use a shackle. You should inspect shackles, like hooks, on a daily routine and before lifting heavy loads. The inspection areas of a shackle are illustrated in Figure 4.
Figure 4 — Shackle inspection
You should never replace the shackle pin with a bolt. Never use as shackle with a bent pin, and never allow the shackle to be pulled at an angle; doing so will reduce its carrying capacity. Packing the pin with washers centralizes the shackle, as shown in Figure 5.
Figure 5 — Packing a shackle with washers
Mousing is a technique often used to close the open section of a hook to keep slings, straps, and so on, from slipping off the hook, as shown in Figure 6. To some extent, it also helps prevent straightening of the hook. Hooks should be moused with rope yarn, seizing wire, or a shackle. When using rope yarn or wire, make 8 to 10 wraps around both sides of the hook. To finish off, make several turns with the yarn or wire around the sides of the mousing, and then tie the ends securely, as shown in Figure 6. Shackles are moused when there is danger of the shackle pin working loose and coming out because of vibration. To mouse a shackle, simply take several turns with seizing wire through the eye of the pin and around the bow of the shackle.
Figure 6 — Mousing
Slings are widely used for hoisting and moving heavy loads. Some types of slings come already made. Slings can be made of wire rope, fiber line, or chain.
Wire rope slings offer the advantages of both strength and flexibility. These qualities make wire rope adequate to meet the requirements of most crane hoisting jobs; therefore, wire rope slings are used more often than fiber line or chain slings.
Fiber line slings are flexible and protect finished material better than wire rope slings. However, fiber line slings are not as strong as wire rope or chain slings and are more likely to be damaged by sharp edges.
Chain slings are most often used for hoisting heavy steel items, such as rails, pipes, beams, and angles. Chain slings are the most appropriate type of sling for hot loads and loads that have sharp edges that might otherwise sever the sling components.
There are three types of wire rope and fiber line slings: endless, single-leg, and bridle. The following paragraphs describe the uses of wire rope and fiber line slings.
An endless sling (Figure7), usually referred to as a sling, can be made by splicing the ends of a piece of fiber line or wire rope to form an endless loop. An endless sling is easy to handle and can be used as a choker hitch. To make a single-leg sling, commonly referred to as a strap, form a spliced eye in each end of a piece of fiber line or wire rope. Sometimes you can splice the ends of a piece of wire rope into eyes around thimbles, and then fasten one eye to a hook with a shackle. In this arrangement, the shackle and hook are both removable.
Figure 7 — Endless slings.
The single-leg sling can be used as a choker hitch in hoisting by passing one eye through the other eye and over the hoisting hook. The singe-leg sling is also useful as a double-anchor hitch and works well for hoisting drums or other cylindrical objects where a sling must tighten itself under strain and lift by friction against the sides of the object.
Single-leg slings can be used to make various types of bridles. Three common uses of bridles are shown in Figure 8. Two or more single slings can be used for a given combination.
Figure 8 — Multi-legged bridle slings.
The bridle hitch provides excellent load stability when the load is distributed equally among each sling leg. The load hook is directly over the center of gravity of the load, and the load is raised level. The use of bridle slings requires that the sling angles be carefully determined to ensure that the individual legs are not overloaded.
It is wrong to conclude that a three- or four-leg bridle will safely lift a load equal to the safe working load of one leg multiplied by the number of legs. This wrong conclusion results because there is no way of knowing whether each leg is carrying its share of the load.
When a four-legged bridle sling lifts a rigid load, it is possible for two of the legs to support practically the full load, while the other two legs only balance it.
When lifting heavy loads, ensure that the bottom of the sling legs are fastened to the load in an effort to prevent damage to the load. Many pieces of equipment have eyes fastened to them during the process of manufacture to aid in lifting. With some loads, though, fastening a hook to the eye on one end of each sling leg suffices to secure the sling to the load.
Use a protective pad to protect a fiber line or wire rope sling from exposure to sharp edges at the corner of the load. Pieces of wood or old rubber tires are often available and handy for padding.
Use the following guidelines when working with rigging tools:
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1. Climbing tools consist of body belts, safety belts, and which of the following other devices?
2. Climbing tools are used for scaling poles and trees and for which of the following other purpose?
3. An electrical worker’s hardhat should be rated as what class?
4. All leather parts of the body belt should be inspected for which of the following conditions?
5. When stored for a period of time, the safety strap should be inspected at an interval of how many months?
6. If the serviceability of the safety strap is in doubt, what action should be taken?
7. When climbing, what tool should you use?
8. To keep leather items soft and supple, what substance should be applied?
9. Leather climbing items should NOT be exposed to which of the following conditions?
10.What result can occur if sharp objects and tools are stored with climbing straps?
11.Which of the following tools is the simplest rigging tool?
12.Which of the following tools is used for hoisting heavy objects?
13.Which of the following rigging tools is used to move loads without tying directly to the object with a line or chain?
14.At what interval should rigging hooks be inspected?
15.A shackle pin should be replaced with what item?
16.When heavy loads are to be lifted, the bottom sling legs should be in what condition to prevent damage to the load?
17.Before lifting a load, what factor should you determine?
18.Slings should be kept free of kinks, loops, and what other condition?
19.A wire rope should be removed from service when the inspection reveals what condition?
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