RIGGING SAFETY

from Freight to equipment to building supplies loads come in all shapes and sizes and there are many different ways to rig them if we miss a step in the rigging process things could go seriously wrong in order to prevent rigging related accidents we need to stay alert and follow the safety rules the first step to preventing accidents is preparation let's begin by taking a close look at a unique set of signals that are used in the rigging process communication is essential in a Rigger's work in order to move a load successfully both the rigger and the crane operator need to use a number of hand signals let's review the basics to indicate to an operator that you want the hook on the crane lowered point downward and move your hand in small circles when the load is ready to be hoisted raise your arm and point up then move your hand in small circles by extending one arm out to the side with your palm facing down and moving your arm back and forth horizontally you can show that you want the crane to stop to call for an emergency stop extend both arms out to the sides with palms down and move your forearms horizontally there are two other special signals that are used only when working with boom cranes to show that you want the boom to be lowered extend your arm and close your fist point your thumb down when you need the boom raised extend your arm close your fist and point your thumb up once you are comfortable that everyone can communicate effectively check with the operator to make sure that the crane has been inspected that way both you and the operator will know that the crane is ready to lift safely also make sure that both of you know the weight capacity of the crane this will help prevent you from overloading it inspecting the hook is important to never use a hook with a broken or bent safety latch the sling could slide off of the hook and damage the load or cause an injury keep in mind that hooks are made to carry loads at their centers never lift a load on the tip of a hook this can cause the hook to stretch and weaken if the hook you are about to use has an opening that is stretched 15 percent or more from its original size or twisted more than 10 degrees don't use it take the time to get another hook once the crane and hook have been inspected you can move on to picking out the proper sling for your job slings are used to carry a load they can be made out of many different types of material such as chain wire rope synthetic fabrics or metal mesh when choosing a sling consider the size shape and even the temperature of the load knowing the temperature of the load is important because some slings may stretch melt or even break in extreme heat by selecting the right sling you can make rigging and controlling the load a lot easier and safer let's take a look a chain sling should be used for lifting your heaviest loads it also works well when you are in a high temperature environment such as a steel mill because it is less likely to be damaged by heat than other types of slings before using a chain sling inspect it for cuts or worn links by pushing the links together and checking where metal rubs metal you can find hidden worn spots and catch other potential problems synthetic slings are the most flexible type of sling and are used when loads have to be protected from abrasion their light weight also helps to reduce fatigue and stress that you and other riggers may experience on the job metal mesh slings are best for lifting objects with sharp edges such as plate steel since the edges can't cut through the mesh metal mesh slings also make it easier to balance alone because of their wide load bearing surfaces the most widely used type of sling is the wire rope sling these are commonly found at construction sites and in other rugged environments before working with a wire rope sling inspect it for broken or severely worn wires check the end connections for corrosion or broken wires as well as kinks crushed wires or unwinding strands if you find any of these conditions don't use the sling since it could be weakened once you have picked out your sling you are ready to attach the load you should start by determining which hitch to use let's check it out a hitch is the way a sling is attached to the load and the hook there are three basic hitches the vertical hitch the basket hitch and the choker hitch you can only use vertical hitches unloads equipped with lifting attachments such as eye bolts or latches to create a vertical hitch just attach the hoist hook to the sling then connect the sling to the lifting attachment a choker hitch works particularly well with wide loads wrap the sling snugly around the load then run one end through the shackle on the other end and fasten it to the hook sometimes a regular choker hitch isn't tight enough in these situations you should use a double wrap choker hitch wrap the sling around the load twice then loop one end through the other and attach it to the hook the most commonly used hitch is the basket hitch to form this hitch cradle the sling around the load then place both ends of the sling over the hoist hook when deciding which hitch to use keep in mind that the same factors that apply to slings apply to hitches as well both the hitch and the sling are affected by the weight size and shape of the load for example because of its length a long metal pole would need a double wrap choker hitch to keep it in place and you would want to use a synthetic sling since its flexibility and strength would help keep the pole stable no matter which hits you are using it's important not to wrap the hoist rope around the load this could damage the rope the hook or the load itself the hoist rope should only be used to lift and lower the hook after you have selected which sling and hitch to use you still need to determine how to prevent the load from damaging the sling the easiest way to do this is to place padding around the sling to protect both the sling and the load you can place wood or other softeners between them this will help prevent the sling from cutting into the load as well as stop the load from causing wear and tear on the sling sometimes a load needs more than one sling to keep it stable as it's being lifted to figure out the safest way to rig the slings we need to look at sling angles a sling angle is the angle between a sling and the load itself by paying close attention to the sling angles for each sling we have rigged we can be sure that the load will be safe and secure while it is being lifted the force exerted on each sling increases as its sling angle decreases if this force exceeds the slings weight capacity the sling could break a sling angle of 90 degrees is ideal because it puts the least stress on the sling there are two ways to get a sling angle of 90 degrees one is to use a lifting attachment and the other is to use a single sling unfortunately most loads don't have lifting attachments and many loads require two slings to find the right sling angle for two or more slings ask your supervisor for a sling angle chart a sling angle chart lists various sling angle factors if you are using two slings to lift a load multiply the sling angle factor by half of the weight of the load that way you can determine what the weight capacity of each sling should be for example the sling angle factor for two slings attached to a load and angles of 60 degrees is 1.15 5 so for a thousand pound load you would multiply five hundred pounds half the loads weight by one point one five five this tells us that each sling would need to be rated for at least five hundred and seventy eight pounds if the sling angles were 45 degrees the chart would tell us that each sling would need to have a weight capacity of at least 707 pounds sling angles of less than 45 degrees should be avoided because they put too much stress on the sling keep in mind that the shorter the sling the sharper the sling angle will be so if you use slings that are too short you could easily overload them causing the slings to break by taking your time and consulting the chart you can catch sling angle problems and find the slings that are right for your lift now that you know how to rig the load it's time to lift it cranes are only intended to lift straight up and down a diagonal lift puts too much stress on the crane and could tip the crane over so before you lift make sure that the operator has positioned the crane directly over the load and that the outriggers are extended and planted firmly on the ground while lifting you also need to be careful of accidental drops most often accidental drops are caused by having a bad angle of the load the angle between the load and the level ground most drops occur when the load isn't parallel to this level ground never let the angle of the load exceed 10 degrees more than that and the load could slip and fall damaging material or injuring people while accidental drops are dangerous the most common hazard that a rigger faces is electrocution and the most frequent cause of electrocution is contact with overhead power lines or electrical equipment make sure that you know the height of any power lines near your job site as well as the location of all electrical equipment before you start work this way you can direct the crane away from danger you should also keep an eye on the weather for instance you don't want to stand next to a crane or hold on to a tagline in a storm if you do you can easily become a target for lightning now that we've rigged the load safely and though what hazards to look out for during a lift we're ready to move on as the lift progresses you need to pay close attention to the load often it can shift and change the angle of the load remember the angle should never exceed 10 degrees from horizontal once the load is in the air the next step is to move it to help control and position the load it is often a good idea to use ropes or it's taglines by putting tension on the tagline you can prevent the load from spinning or help direct it toward its destination taglines can also help you maneuver the load into tight places during the lift stop periodically to make sure that the load is secure as you travel with the load don't carry it above people or allow anyone to walk under it when you come to a stopping point remember a suspended load should never be left unattended it's an accident waiting to happen move to within a few inches of a good landing point then slowly lower the load until it is grounded once the load is at its final destination make sure to remove the slings from the hook if they are left on the hook they can snag on other objects when the crane starts to move again make sure to return the slings to their proper storage place now that we know how to rig lift and land a load let's look at one last set of precautions you should take whenever you are rigging wearing the right protective clothing for the job the right clothes and gear can protect you from cuts bruises and other more serious injuries as well first it's important to wear heavy leather gloves they will protect your hands from rope burns and sharp objects you should also wear safety shoes with steel toes to protect your feet from heavy equipment or dropped loads a hard hat and safety glasses we'll help protect your head and eyes from falling or hanging objects sleeveless shirts can leave arms exposed to sharp objects and machinery make sure that you are wearing a shirt with sleeves that can protect you from cuts and abrasions and don't forget to tuck in your shirt tails so they won't get caught on the sling or the load rigging plays a pivotal role in crane operations if a load is not rigged properly the consequences can be devastating but by taking the proper precautions you can get the job done safely let's review before rigging a load make sure that both you and the crane operator know the standard pan signals know the weight capacity of the crane and the lifting accessories that you are using familiarize yourself with the different types of slings and hitches that can be used to rig a load make sure every load you rig is secure and that the sling angles are safe never carry a load above other workers or allow anyone to walk under a load and be sure to wear the proper of protective clothing and equipment needed for the job you're working on see it's not so hard after all once you get the hang of it it can be easy to rig a load safely

Channel: SSi Safety

Views: 339,584

Rating: 4.8518028 out of 5

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Id: Xyr4YRbbK1k

Length: 18min 22sec (1102 seconds)

Published: Fri Jan 23 2015