Rigging and Lifting

Number of clips Cable Clips

3 x wire rope diameter + 1

Weight of 1 Cubic Foot of Steel

500 lbf (489.6 lbf)

Spacing between clips Cable Clips

7 x wire rope diameter (Alberta book)

Double Choker Hitch

Long loads or loose loads which need to be lifted level may be hoisted with this.

Lever-Operated Pull-Lift Hoist

Or a Screw Gear chain hoist is used for horizontal pulling. Only one person should pull on this type of hoist as it is easy to overload. - Use for horizontal pulling

Block Centre Pin

Sometimes called the sheave pi, transmits the sheave load to the strap. It is prevented from turning by a keeper.

Storing and Handling Wire Rope

Store all wire rope rolled in a coil or on a spool, in a dry place away from extreme heat and moisture.

Inspection of Chain Hoists

- A set of test gauges may be used to inspect the load chain and hooks of the hoist. - If there is evidence of severe overloading, you should thoroughly inspect all parts of the hoist. - To inspect a chain hoist, examine the hooks and chains very thoroughly

Overhaul of Chain Hoists

- Either use the parts specified by the manufacturer - Or send it to a qualified repair shop

Load Chains Inspection

- Use the opening at the wide end of the gauge to check that a chain link has the proper gauge. The, with the chain hanging freely, attempt to insert the small end of the gauge. then, with the chain hanging freely, attempt to insert the small end of the gauge between the links. If the gauge is too wide, it indicates that the links have stretched and narrowed because of overloading. - If the gauge enters the link up to the first stamped "OK", it indicates that there is little or no wear on the links - If it enters to the second stamped "R", there is evidence of considerable wear and/or stretch. The chain hoist should be thoroughly inspected and overhauled. - If the gauge enters the link to the third step stamped "C", it shows excessive wear and/or strethc. Replace the chain and overhaul the hoist.

Snatch Block

Can be a single or multiple-sheave block. It opens on one side to permit the rope to be slipped over the sheave so that it does not need to be threaded through the block. They are normally used when it is necessary to change the direction of the pull on a line. As the direction changes, the angle between the lines increases, the stress on the block and hook is reduced

Hand Signals

Ensure that only one signaller is used when making a lift or move. If the signaller and hositing-equipment operator cannot see each other, a relay person or a two way radio may be used.

Lower Load

Extend right arm downward, forefinger pointing down, then move hand in small circle

Hoist Load

Extend the right arm straight out and raise the forearm to vertical, forefinger pointing up, then move hand in small circle

Screw Gear Hoist

For infrequent use - Used for hosting

IWRC

Independent Wire Rope Core

Wire Rope Size

Is measured across its greatest diameter

Cable Clips Rule of Thumb

Never saddle a dead dog! The saddle is opposite the U-bolt

Excess Oil on Chain Hoists

Occasionally in a manufacturing plant chain hoists used for lowering material into oil baths or for holding material while it is sprayed with oil. This may cause the load chains to be coated with too much oil. Then the hoist is operated, the oil is transferred to the sprocket and may eventually find its way into the load brake, thus reducing its holding power. For service such as this, use screw-geared or differential hoist.

Safety

Routine maintenace often involves lifting or moving heavy parts and equipment. Before doing this always consider the following factors: - The Charachteristics (weight, shape, centre of gravity, etc.) of the obkect to be moved - Its present location - The location it will be moved to - The equipment available to help you move the object - The safety precautions which may have to be in place for the move - The path of the move The weight of the object to be moved determines the type and size of lifting tackle used. Pay careful attention to the overall dimensions and to the dimensions of mating parts. The pathway and the final resting place must accommodate these dimensions.

Chain Hoists

There are four types of chain hoists: the spur-geared, the screw-geared, the differential, and the pull-lift types. The first three types are used for hosting, while the pull lift type is primarily used for pulling in a horizontal direction. Only forged steel should be used for hoist parts that are subject to stress, such as hooks, swivels, chains, sprockets, gears, and similar parts. All chain hoists are designed with their lower hooks as the weakest parts. If the hoise is overloaded it is first indicated by the spreading or opening up of the lower hook. Do not interchange the two hooks on a chain hoist.

Cable Clips

(Crosby Clips) The most common method used to make an eye or attach a wire rope to a piece of equipment. Various Types include; -U-bolt (saddle) clips -Double Saddle (safety or first-grip) clips -Double-base clamps Easy to examine and, when installed according to manufacturers' specifications and current WCB regulations, they have 80% of the rope strength. All clips must be drop forged steel. Double-saddle clips are preferable to U-bolt clips because they cause less damage to the rope. The number of clips required is determined by the rope diameter. Still greater efficiency can be obtained by the use of double-base clamps. These give a greater clamping force on the rope without damaging it. This increases rope life and safety.

Endless Slings

(Grommet slings) Can be used in a variety of configurations. They are usually made of fibre rope or synthetic webbing. They are light to handle and do not damage the loads, but because they are subject to sharp bends, the rend to deteriorate more rapidly than most other types of slings.

Weight of 1 Cubic Inch of Steel

0.2836 lbf

Abrasian Resistance

Larger diameter wires on the outside or contact layer have better abrasion resistance than small wires.

Block Shell

Provides protection for the sheaves and acts as a guide to keep the rope in the sheave groove. Steel shells are used on all blocks with wire rope. They add strength, rigidity and protection for the block.

Maintain Then Rope Properly

*** six broken wires in one strand in four lays -Inspect the rope regular according to the manufacturer's guidelines and WCB regulations -Discard damaged or kinked sections by cutting them out -To remove rope that is worn due to vibration, cut off a section next to the anchorage and refasten the rope -Lubricate the rope regularly according to the manufacturer's recommendations. -Store all unused rope in a clean, dry place, where it will be protected from the elements -Minimize uneven wear by moving the rope at regular intervals so that different sections of it are the critical wear point -Change layer and crossover points by cutting a few feet of rope from the end of the drum and refastening it. Make the cut long enough to: -Change the layer at least one full coil from its former position -Move the crossover points one-quarter turn around the drum

Classification of Blocks

- Traveling or falling block is a block that is attached to the load being lifted or moved. It travels with the load. - A standing block is fixed at a stationary object. This take the force of the loading.

Unwinding from a Spool

-A quick way of mounting a spool is to use a length of pipe and some blocking -Do not take wire rope off the side of the spool a wrap at a time, as this often results in kinks -When taking a length of wire rope from a spool, rotate the spool on a spindle or turntable, or roll the spool along the floor -Before cutting a length of wire rope from a reel, "seize" of warp each side of the proposed cut. Use friction tape, or, if the end is to be welded, light wire. If one end of the wire is to go through a hole in a drum, a good practice is to "braze" or weld the end and then remove the seizing -If using an impact cutter keep the cutter in the same position throughout the cut. -After removing a length of rope from a spool, wind the slack back onto the spool and tie down the free end

Precautions Using Shackles

-All pins must be straight and all screw pins must be completely seated. Cotter pins must be used with all round pin shackles. -Never replace the shackle pin with a bolt; only use the properly fitted pin. Bolts are not intended to take the bending that is normally applied to the pin. -Destroy worn shackles -When using a screw pin shackle, secure the pin with wire through the hole to the shackle body to prevent the pin from unthreading. -Never allow a shackle to be pulled at an angle. Centralize whatever is being hoisted on the pin by using suitable spacers. -Do not use screw pin shackles if they can roll under load and unscrew

Checking Sheaves for Wire Ropes

-Check flanges for wear chips and cracks -A proper fitting sheave groove should support the rope over 135-150° if rope circumference -Check grooves for proper size -Check sheave grooves for wear

Lubricating the Wire Rope Properly

-Ensure that the rope is clean and dry before the lubricant is applied -Use a light penetrating cleaner to soften the built up grime before removing it. Contact the lubricant supplier regarding the proper cleaning oil to use. Do not use gasoline or kerosene, since too much of it will remove the internal lubricant. -The main objective in external lubrication is to fill any gaps in and between the strands so that a complete seal is provided. The frequency required depends on the particular installation -Apply the lubricant using one of the following methods depending on the viscosity of the compound applied, the length of rope involved and limitation of facilities --Light Oils -Apply light oils by brushing, running the rope through and oil bath, spraying, drip method or mechanical force feed. -For maximum penetration, apply the lubricant to the rope where it "opens up" as it travels around a sheave or winds on the drum --Medium and heavy oils -Apply these lubricants warm. Apply them by brush or by running the roope through a funnel containing the lubricant. You may also use an air balst provided that only dry air is used and all proper safety precautions are taken -Even though brushing and dripping methods of lubricating long ropes are tedious, they give you time to inspect the rope. -The rope should be properly lubricated ata ll times. Inspect the rope often to see when it must be done

Environment

-Galvanized rope must be used in salt water applications -Stainless steel must be used in corrosive, acidic environments

Using the Rope Correctly

-Never overload the rope -Avoid shock loading -Apply the power smoothly and steadily -Ensure that the rope winds properly on the drum -Ensure that the rope ends are properly seized -Ensure wire rope has a run--in period before operating at full load speed -On equipment having multiple falls of other than non-rotating ropes, a new rope will stretch and unlay slightly, causing turns to appear in the load block. If the anchorage is not fitted to a suitable swivel, disconnect it, remove the turns, and reconnect the anchorage.

Strength

-Steel core rope is stronger than fibre core. -For a given diameter rope, the fewer wires in the rope, the greater the strength

Flexibility

-The more wires in the strand, the more flexible the rope will be. -The more strands in the rope, the more flexible the rope will be.

Wire Rule of Thumb

3/8 is 2000 lb and 1/8 is 1000

Weight of 1 Cubic Foot of Wood

35 lbf

Weight of 12x12x1 of Steel

40 lbf

Safe Working Load Limit For Wire Rope

A rule of thumb for calculating the SWL of a wire rope is that 3/8" in diameter will support 1 Ton (2000 lbf) Each 1/8" increase in diameter is = to 1 to increase in SWL

Swaged Sockets

Are also permanent terminal attachments for wire rope. They are made by compressing a steel sleeve over the rope with a hydraulic press. Properly made they are 100% efficient. If you see one broken wire, that is enough to condemn the rope section.

Crane-and-Hook Blocks

Are equipped with heavy iron cheek weights. Well suited to high-speed applications and heavy loads.

Eye and thimbles

Are frequently used as wire-rope attachments. With the exception of some slings, all eyes must include rope thimbles to maintain rope strength and reduce wear. If a thimble is not used on a spliced eye, the efficiency of the connection can be reduced by as much as 10% because the rope flattens under load. There are great differences in efficiencies of eye formation but little difference in appearance. WCB requires the identification of each eye formation with tags.

Wedge Sockets

Are intended for on-the-job attachments and for quick rope replacement. Their principal advantages are the ease and speed of applying and detaching. They are used to secure a ball or hook on a mobile crane. the efficiency of a wedge socket is low -- only 70% of the strength of the rope. Be sure to secure the dead end properly

Single Basket Hitch

Are made from a single length of sling material passed through a load. both ends of the sling attachment to the main hook. Do not use these on loads that could tilt and slide out of the hitch. Never incline the legs of this hitch less than 60° to the horizontal. This will prevent the legs from sliding towards each-other. Use longer slings to spread the legs apart without having the legs at an excessively low slope.

Chains

Are made of a series of interconnected links. Each link is made of wire or rod bent in an oval shape and welded together at one side. The diameter of the wire rod determines the chain size. Use chain for hoisting only when no other method of slinging or rigging is available. Use chains in hoisting operations only when their ability to withstand high temperatures and abrasion is required. Chains can break without warning. Only one link in a chain needs to break for the load to drop.

Single choker Hitch

Are made of a single length of sling material hooked back to itself just above the load. There are several methods of securing one end of the sling back into itself to form the choker, but none will totally secure the top of loose loads

Wire Rope Blocks

Are much lighter than crane-and-hook blocks. Well suited to high-speed applications and heavy loads. Are not intended to withstand the heavy service and abuse expected of the crane and hook blocks.

Double Basket Hitchs

Are self adjusting in the sense that each leg carries it's share of the load. Therefore to calculate the SWL use the following: SWL = SWL1 x H/L x 4

Synthetic Fibre Ropes

Are used extensively in industry, due to their strength, shock-loading capacity, and resistance to natural weathering. They are made from nylon, polyethylene or polypropylene. Most industrial synthetic fibre ropes are the standard three-strand, right-hand-lay rope, but braided and other special construction styles are also available. On synthetic fibre ropes, finish all knots with an additional safety knot to prevent slippage.

Tackle Blocks

Are used in conjunction with fibre ropes, both natural and synthetic fibre. They are similar to wire-rope blocks but lighter weight and have less capacity. The sheaves in the block should be of the proper size for the rope being used and must be free and well lubricated.

Equalizer Beams

Are used to equalize the load on the sling legs and to keep equal loads on dual hoist lines when making tandem lifts. They are fabricated to suit a specific application and must meet WCB specifications. The load capacity of beams with multiple attachment points depends upon the distance between the points. For example, if the distance between the attachment points is doubled the capacity of the beam is halved.

Blocks

Are used to lift heavy loads using a small amount of effort. The ratio of the load to the effort is called the mechanical advantage. The blocks used in construction rigging range from custom-designed, 400-ton capacity units through all times of crane hook blocks, to wire rope blocks and snatch blocks, down to the simplest of tackle blocks. The essential parts of any block are shell, sheaves, a centre pin, the straps, and becket.

Spreader Beams

Are usually used to support longs loads during lifts. They remove the risk of the load tipping, sliding or bending. They also remove the possibility of low sling angles and the tendency of the slings to crush the load.

Lubrication

As important as lubricating any other piece of machinery. Consult your rope manufacturer for lubricants designed especially for an operating rope or a standing rope. The lubrication the rope gets during manufacturing is adequate for initial storage and for the early stages of the rope's working life. However, it must be supplemented regularly according to the manufaturere's instructions. If not regularly lubricated, the rope will deteriorate rapidly in the following ways: -The wires become embrittled from excessive corrosion and break easily. -The wires in a rope are suject to frictional wear as they move together during ooperation. Lack of lubrication increases wear and reduces strength -Ropes not in regular service or those not considered as operating ropes are vulnerable to weathering. If the weathering wears through the external lubrication, excessive moisture can gradually leach out the internal lubrication. This causes the core and wire to rust and deteriorate.

Block End Fittings

Can be equipped with various combinations of end fittings including hooks, wedge sockets, clevis, shackles, and swivels of all types. The blocks may also be equipped with a becket which is the anchorage point for a rope end.

Wire Rope Clasification

Classified by four factors: - The number of wires per strand -The number of strands -The type of core -The lay Ex: 6x31 Warrington Seale, IWRC, regular lay -6 Strands -31 wires per strand -Warrington Sealle indicates the configuration of the wires in each strand -IWRC indicates the type of core used in the rope. Independent Wire Rope Core -Right regular lay specifies the way wires and strands are wound

Synthetic Web Slings

Come in a variety of shapes and widths. Their relative softness and width protect the loads they are lifting from being marred or scratched. Heat and friction damage these. Commonly Endless, Standard Eye and Twisted Eye

Commonly Used Hooks

Commonly used types of hooks are standard, adjustable, sliding and dual sliding.

Left Regular Lay

Consist of wires twisted to the right in the strands, and the strands then twisted to the left to produce the rope.

Single Vertical Hitch

Consists of a single leg of sling material with a hook and an eye at each end

Double Basket-Wrap Hitch

Even loads can be securely rigged for hoisting with this configuration. To do this wrap the sling completely around the load. This double wrapping presses all the components together, preventing even the top pieces from sliding out of the rigging.

Angular Loading of Eye bolts

Even with shouldered, the SWL of eye bolts are reduced by angular loading. When installing a shoulder-type eye bolt, make sure that: -The shoulder firmly contacts the working surface (you may need to use washers or shims) -The nuts are properly torqued -The tapped hole for the bolt has a minimum depth of on and one-half times the bolt diameter -The thread in the tapped hole and on the bolt are in good condition.

Spur Gear Hoist

For frequent use and minimum effort, this is used because it is the most efficient. - Used for hosting

Differential Hoist

For very infrequent use where light weight and low cost are important. - Used for hosting

Choker Web sling

Has a larger triangle containing a slot at one end and a smaller triangle at the other. The smaller triangle can be passed through the slot of the larger triangle to form a choker hitch.

Basket Web Sling

Has metal triangles of equal size at each end

Lang Lay

Has the wires and strands twisted in the same direction. The core design is the same as that of the regular lay. Advantages; -Is more flexible than regular lay -Has more area in contact with the drum spool or sheaves, this wearing longer Disadvantages: -Both ends must be permanently fastened to prevent unwinding -It must not be used with a single-part lift -It must not be used with swivels -It cannot be used for slings -It does not resist crushing

Preformed Wire Ropes

Have the twist or helix set in each wire and strand to eliminate internal stress. They do not fly apart when cut. They can be spliced without seizing (binding); when wires break, they lie flat in position on the rope.

Basket Hitch SWL

If this sling is used in basket hitch configuration with the legs of the basket hitch inclined SWL = SWL1 x H/L x 2 SWL = 2000 lbf x 3/5 x 2 SWL = 2400 lbf

Wire and Fibre Rope Considerations

If you use fibre rope or wire rope to make slings you must remember the following: -A knot can reduce the breaking strength of the fibre rope by up to 50% -Cable clips correctly attached to the wire rope reduce it's breaking strength by 20% -Sharp corners off loads should have padding or soft corners in place to reduce abrasion on the rope.

Determining Rope Anchorage on a Drum

Improper attachment on a drum will cause the loaded rope to climb over the next wrap and pile up on itself. This results in excessive rope wear, usually concentrated in one or more places. To obtain good drum winding, the rope must be started from the proper flange. Deciding which flange to use depends on whether the rope is left-lay or right-lay and whether the rope leads from the top of the bottom of the drum.

Braided Synthetic Rope

In recent years, their use has been increasing steadily. They do not stretch as much as other types, certain types are stronger than many laid ropes of the same fiber. A synthetic rope that has a braided sheath over a core is soft, strong, and flexible and does not twist or kink. The load is divided equally between the sheath and the core so that, even if the outer sheath is damaged, 50% of the rope's strength remains in the core.

Cores

Is built into a wire rope to support the strands of the rope and maintain the basic rope shape. -Fibre Core (FC) are usually made from sisal but can be made from polypropylene or other synthetic rope material if the wire rope will be subject to weathering. On requests, manufacturers can supply wire rope with an oil-impregnated fibre core to self lubricate the inner wires. -Independent Wire Rope Cores (IWRC) or Wire Rope Cores (WRC) are used when the wire rope is subject to sudden heavy loads, crushing, or heating. In small diameter wire ropes, the wire rope core is replaced by a strand core. -Strand Cores another strand of the rope as core

Right Regular Lay

Is the most common wire rope. This consists of a number of wires twisted to the left around a small core to form each of the six strands. These strands are the twisted to the right around the main core to form the final rope. Wire ropes of six strands are the most common

Nylon Rope

Is very strong and elastic. It is used where shock loading is common or when a rope need to be smaller than hemp or jute but of equal strength. It resists mineral oils and greases, but is affected by paint, linseed oil and acids. This type of rope becomes slippery when wet and lose a small part of its strength, but it does not rot or mildew. The most expensive of the common industrial synthetic ropes.

Metal Mesh Slings

Loads which are two abrasive or too hot for synthetic webbing , yet require the wide bearing surface of a web belt are rigged with slings made of metal mesh. These are usually equipped with triangle ends which permit the use of either a basket or choker hitch.

Natural Fibre Ropes

Made from several different fibres. In decreasing order of strength; hemp, sisal, jute, and cotton. Hemp is the natural fibre rope used most commonly in industrial rigging and will be used in the following descriptions. The usual method of construction for fiber rope is reverse twisting. This gives rope stability and keeps it from twisting under the strain. The method of construction is as follows -Fibres from 6-20 feet long are combed to bring them parallel to each other -A definite number of fibres are right-hand twisted to form a yarn -A number of yarns are the left-hand twisted into a strand -Finally, three or four of these strands are right-hand twisted to form the rope

Safe Working Loads for Rope

Manufacturers rate their ropes by their breaking strength. When using rope to hoist you must not approach this limit. If you are lifting materials and equipment, the must be no heavier than 1/5 of this breaking strength. People it is 1/10

Using Wire Ropes

Maximum broken wires Six broken wires in one strand in four lays. *** Require careful use, handling and maintenance for satisfactory performance, long life and safety. When using wire ropes, you must choose the right rope, maintain the rope properly and use the rope-related equipment correctly.

Trunbucles

May have end fitting that can be eyes, jaws, stubs, hooks or any combination of these. Their rated load depends upon the outside diameter of the threaded portion on the end fitting and the type of end fitting. The jaw, eye and stub types are rated equally and the hook types have reduced ratings. All of these used in hoisting and rigging should be of the weldless construction and fabricated from alloy steel. When using hook types, apply mousing to any hook without a safety catch. If it is to be used where there is vibration, it is extremely important to lock the frame to the end fittings to prevent it from turning and loosening. Use a lock wire to ensure that these will not loosen. Lock nuts or jam nuts are not effective and add greatly to the load in the screw thread The tightening them, apply the same torque to is as you would to a bolt of equal size. Inspect them frequently for cracks in the end fittings, especially at the neck of the shank. Also, check for deformed end fittings, deformed bent rods and bodies, cracks and bends around the internally threaded portion, and signs of thread damage. Refer to manufacturer's specifications for the correct SWL.

Slings

Most items that require hoisting have no provisions for attaching the load the the lifting device. So these are used. To protect the load and the rigging equipment place padding or soft corners (preformed metal brackets) between the sling and any sharp corners on the load.

Poly Ropes

Polyethylene, polypropylene and other materials of this group are used as an inexpensive substitute for nylon rope. Poly ropes have the advantage of buoyancy and are therefore used a great deal around water. The tensile strength varies slightly among the poly ropes.

Use Related Equipment Correctly

Proper maintenance of the equipment over which the ropes operate is an important factor in the ropes life. Worn grooves, poor alignment of sheaves and worn parts resulting in shock loads and excessive vibration will have a deteriorating effect -Repair or replace faulty guides and rollers -Inspect sheaves and replace those that have deeply worn or scored grooves, or have cracked or broken rims. -Use thimbles in eye fittings at all times -If the sheaves or drums bear the imprint of the rope, they should be machined clean or replaced with harder material. -Check sheave and roller bearings for free operation. Sticking will cause unnecessary wear. -Check the fleet angle. An excessive fleet angle will cause severe abrasion on the rope as it winds onto the drum. This condition can severely shorten rope life.

Lay

Refers to the direction in which the strands of a rope are twisted together.

Lay Length

Refers to the distance along the rope in which a strand makes one revolution.

Safe Working Loads of Slings

Refers to the load which that sling can safely lift while the slings is used in a vertical hitch (with only one leg) We will refer to this as SWL1

Lay

Right-lay ropes are the most common style used. -Left-lay ropes are used for special applications

Fibre Rope Size

Rope is measured by diameter or by circumference. This can be confusing because sometimes ropes up to one inch in diameter and ropes over one inch by circumference. Note that a rope 1 inch in diameter has a circumference of about 3 inches. Select your rope carefully.

Grades of Chain

Several are available, but the only grade acceptable for overhead hoisting is grade A. Each link must bear an "A" stamped into its surface.

Eye bolts

Should be of forged alloy steel and equipped with shoulders or collars (shoulder-type). The plain (shoulder-less) is fine for vertical loading only but as soon as it is loaded at an angle, the SWL is severely reduced SWL for plain and shoulder-type eye bolts under vertical load are the same. Angular load is not recommended.

Chain Slings

Should be supplied with a master ring at one end and a hook at the other. The large master ring is designed to fit over a crane's main hook. Then either the chain's own hook is hooked directly to the load, or the chain is wrapped around the load and its hook secured to the master link.

Chain Wear

Shown at the bearing surface of each link. When the amount of wear equals 5% of the link diameter for chains less than 1" or 10% for chains over 1", stop using it for hoisting.

Double-Wrap Choker Hitch

Similar to the double wrap basket hitch in that both squeeze the load from all sides. These may be used singly or in pairs.

Crush Resistance

Steel-core ropes resist crushing better than fibre-core rope.

Grades

The breaking strength or break load of rope is the force needed to break the rope. The type used in hoisting run from traction grade, with a breaking load of 80 - 90 tons psi of wire material, to special improved plow grade, with a breaking load of 120 - 130 tonnes psi. Improved plow quality with a breaking load of 110 - 120 tons psi is the most commonly used grade in a mill.

Wire Rope

The lifting means most commonly used. It is better adapted for haulage and transmission than are natural and synthetic ropes. It is strong and unlike chains gives a good warning for failure when it is defective. Inspect before using to check that it is safe. Consists of small diameter wires wound around a small core to create a strand. Strands (normally six are wound around steel or fibre core to create a rope.

Dead End on the Wedge Socket

The tail end of the dead end should be a minimum of 20 rope diameters, but not less than 10" (6-9" in manual)

Hook Isnpection

The wide end of the gauge is used to caliper the opening of the hoist hook. If the opening is the gauge, destroy and replace the hook. The size stamped on the gauge must agree with the capacity of the hoist.

Cable Clips Lays

There are right and left-hand clips, take care to use the proper clips. Improper application of even one clip may reduce the efficiency of the connection to 40% Always put the U-bolt section of the clips on the dead or short end of the rope. Never use any kind of clip to directly connect two straight lengths of rope. If you need to connect two ropes end-to-end, use these clips to form an eye (with thimble) in each length and connect the eyes with a shackle.

Types of Slings

They may be made of fibre rope, wire rope, chain or webbing. They may also be attached to loads in a variety of configurations, each with its own name.

Block Types

They take their names from the purpose for which they are used, the position they occupy, or from a particular shape or type of construction. They can be designated according to the number of sheaves they have (single, double, triple, etc) For the millwright, the most commonly used types are: - Crane hook blocks - Wire-rope blocks - Tackle Blocks - Snatch Blocks

Block Sheave

Transmits the load imposed by the rope to the centre pin, straps, and connections. On fibre-rope blocks they should be cast steel because of its greater strength, hardness and abrasion resistance. Fibre-rope sheaves are not used with wire rope because their diameters are too small. Never run fibre rope over sheaves that have been used with the wire ropes rapid rope damage will result.

Shackles

Two types are commonly used in rigging. They are the anchor (bow-type) shackle and the chain (D-type) both of which are available with screw pins or round pins. Shackles are sized by the diameter of the steel in the bow secction

Bridle Hitch

Two, Three or more legs may be used together to form one. They are generally used on all loads which provide suitable attachment points. The load will be stable if the attachment points are above the load's centre of gravity. When its has more than two legs you cannot assume that all legs are sharing the load equally. Regardless of the total number of legs, the full weight of the load might be shared by only two legs. The other legs may simply be balancing/

Choker Hitches

Use a similar formula except that the ration is never less than 3/4 SWL= SWL1 x 3/4 If the choker angle is over 45° or less, use the following formula: SWL = SWL1 x H/L These are often used in pairs to lift loads in a horizonta; position. To calculate the SWL of such sling configurations use the following formula: SWL = SWL1 x A/B x H/S x 2

Two-Leg Bridle Hitch

Uses the same formula as the basket hitch providing that both legs of the bridle hitch are equal in length. Calculating the SWL of bridle hitches with legs of unequal length or with load attachments of unequal height. In this case the smallest height or length as H or L in the same formula SWL = SWL1 x H/L x 2 SWL = 2000 lbf x 3/5 x 2 SWL = 2400 lbf

Hooks

Various hooks are available for hoisting and rigging ooperations. Several safety procedures apply to all hooks: 1) They are forged alloy steel and generally stamped with their rated safe working load 2) Make sure that all hositing hooks (except grab and sorting hooks) are equipt with safey catches. 3) Inspect all hooks frequently -Look for wear in the saddle of the hook -Look for cracks, sever corrosion and twisting of the hook body -Measure the throat opening. If there is any evidence of throat opening or distortion, destroy the hook. 4) Commonly used types of hooks are standard, adjustable, sliding and dual sliding. 5)Make sure the loads are balanced on the Hook.

Natural Fibre Rope Hardness

Varying degrees of tightness of the twisted yarns and strands determine whether it is a hard-laid, medium-laid, (also called common or standard) or soft-laid rope. Soft laid rope has the greatest tensile strength but gives poor service if run over sheaves, and it does not withstand abrasion well.

Block Straps/cheek

Weights transmit the sheave load to the connection and add rigidity to the block.

Cappel Sockets

When properly installed and frequently inspected it also gives 100% efficiency. Their efficiency depends entirely upon the wedges being kept tight. They allow for easy, frequent inspection of the whole section of rope where it is gripped.

Choosing and Using Fibre Ropes

When selecting rope for a lifting job, use charts to decide what you have. Refer to manufacturers specifications for the breaking strength of a rope. -Select the right type and size of rope for the job -Apply whipping (seizing) before cutting the rope to the required length -Apply loads with a steady strain. A sharp heavy jerk will break a rope more readily than a steady pull. Do not overload a rope. For a new rope, the working strength is 1/5 of the breaking strength. For a used rope, increase this safety factor. Store rope in a dry room away from moisture and any extreme heat. If possible, hang a rope on a large wooden peg to ensure air circulation. Dry rope thoroughly before storing it.

Use of Shoulder-Type Eye bolts

When using an eye bolt to lift, keep bending to a minimum. Always apply the load to the plane of the eye, especially when bridle slings are used. When lifting with eye-bolts, always use a shackle to ensure that the lifting angle is above 45°. When they cannot be kept in line with each other when tightened, insert thin washers or shims under the collars. This allows you to align them while maintaining proper tightness.

End Fittings and Connections for Wire Ropes

Whenever possible, use load-rated fittings. This means that the safe working load is stamped on the fitting. For overhead lifting, use only weld-free forged fittings.

Estimating the Weight of Lifted Objects

You can use simple rules of thumb to calculate the approximate weight of most objects: - The approximate weight of a cubic food of steel is 500 lbf (the precise weight is 489.6) - The approximate weight of a cubic foot of wood is 35 lbf

Poured Sockets

Zinc (or spelter) sockets are standard drop-forged sockets. They are permanent terminal attachments for wire rope. They are most commonly used to secure cables onto passenger or freight elevators. When properly attached that are 100% efficient. Epoxy resins are also used for poured sockets.