[Music] in this video you will learn some basic rigging devices as well as some basic rigging techniques and how to safely apply them in the [Music] field in the world of rigging there are three basic hitches the straight leg vertical hitch the choker hitch and the basket hitch regardless of the type of Sling or hitch being used the user must ensure that the sling and rigging Hardware have working load limits that exceed the actual loading imposed on the sling and the rigging Hardware attached also crane operators and riggers should be aware that by moving a load harshly you can easily double the loading on the slings and Hardware attached synthetic or steel-based web round wire rope chain mesh slings are an essential part of any lifting and rigging situation but can be confusing and this confusion can create an un safe situation on one of your job sites so what sling is the right one for the job from materials shapes and weight ratings to most common uses we're going to cover the what's what on slings built for any task there are five common types of slings found on job sites they are broken into two main categories synthetic and steel based let's start with the most common types of slings synthetic there are two main types of synthetic slings web and round we'll start with the synthetic web sling synthetic web slings are flat synthetic lifting products made of webbing material and feature fittings like flat or Twisted eyes on each end synthetic web slings are inexpensive lightweight durable and strong as well as flexible easy to handle and can adjust to irregular loads while maintaining a secure grip because of this they are the most versatile and widely used multipurpose lifting slings synthetic slings are exceptionally resistant to Rod or mildew and are not normally affected by grease or oil they can also be fabricated with wide loadbearing surfaces and are still easy to rig and handle most web slings are available in thicknesses from 1 to four ply and have a capacity from 950 to over 200,000 lb synthetic web slings are broken into two main groups nylon and polyester nylon web slings come in either regular or heavy duty webbing and will stretch approximately 10% at the working load limit they can also be used in alkaline environments nylon slings can not be used in acidic environments or around any type of bleaching agent polyester web slings are the most popular cost-effective sling available and come in standard and heavy duty webbing and stretch approximately 7% at the working load limit these slings can be used in most acidic environments or when bleaching agents are present but they cannot be used in alkaline conditions they also are non-sparking non-conductive and safe to be used in explosive atmospheres to improve either nylon or polyester slings durability wear pads are common to protect against cutting puncturing or abrasion web slings either nylon or polyester are used in nearly every industry and for lifting everything from rocks for landscaping to pipes and beams for skyscrapers now let's talk about synthetic round slings synthetic round slings are most commonly made of a continuous loop of polyester yarn covered by a double wall tubular polyester jacket and are colorcoded for easy identification they are especially useful for for lifting tubes pipes or materials that could be damaged with other rougher slings round slings can be used in chokers basket or vertical hitches synthetic round slings normally range in body diameters from 5/8 to 3 and 5/8 in but custom slings are also common synthetic round slings have lifting capacities from 2600 to over 180,000 lbs some of the advantages of round slings are the jacket protects from erosion abrasion and UV degradation as well as securely gripping the load the jacket also resists moisture absorption rotten mildew and their low stretch makes them great for lifts with low Headroom next we're going to cover Steel based slings there are three types of Steel based slings chain wire rope and mesh this is an alloy chain sling alloy chain slings are the most durable of all sling types they are well suited for extremely heavy or rugged loads as well as high temperature temperatures that would destroy other types of slings alloy chain slings are made up of four parts masterlink ID tag sling [Music] legs and lifting attachments each of these parts has a few different options depending on their intended use like wire rope slings alloy chain slings can have anywhere from 1 to four sling legs alloy chain slings are easy to inspect can be repaired by placing individual links or link segments after proof testing that can be recertified to be used in the field they're also easily adjustable which can be done by removing links or link segments alloy chain slings can be found in 930 seconds of an inch to 1 and 1/2 in and have a lifting capacity between 3,500 lb and over 90 tons while these slings are perfect for the most intense jobs they are typically more expensive weigh more and have a tendency to damage the load alloy chain slings are mainly used when other slings are likely to be damaged like in foundies steel mills and heavy machine shops up next is the wire rope sling the low cost and ease of use make wire rope slings popular among Crews and they excel in lifts while protecting a fragile load is essential typical wire rope slings consist of four main parts individual wires multi-wire strands a fiber or steel core and lubrication the individual wires are braided into strands which are then laid around a core in a helical pattern to produce the sling there are different types of cores strand patterns and lays depending on the sling meaning that many wire rope slings are designed specifically for lifting certain materials or lifting in certain situations overall these slings are more durable than synthetic slings and more cost effective than chain slings they have the lowest cost per ton of lift of all slings and are known for their strength ability to bend without Distortion and to hold up against abuse or abrasive wear if your wire rope sling does does get damaged the master links and hooks can be reused which helps cut down on replacement costs wire ROP slings can range from a/4 of an inch to 3 in in diameter and have capacities from 1,400 lb to 153 tons traditionally wire rope slings are used for hot materials Crane or elevator wires and general construction where loads aren't in danger of being damaged when lifted they are mainly used in machine shops steel warehouses and other metal working Industries in order for any sling to be used on a job site regardless of the type they're required to have a legible and present safety tag any sling without this must be removed from service and replaced shackles are commonly used to attach a sling to a load a screw pin shackle which consists of two pieces the shackle bow and the pin is often the shackle of choice in pick and place applications Crosby shackles discussed in this video are Manu manufactured with a patented Quick Check feature that incorporates two marks forged into the shackle bow at 45° angles from vertical on each side these quick check marks are used to quickly check the angle of a single leg hitch when the shackle pin is secured and the pull of the load is off vertical resulting in a side loing circumstance these quick check marks are also utilized to quickly check the approximate included angle of a two-leg hitch before selecting the correct piece of rigging hardware for your application you should determine that the diameter or width of the rigging Hardware being used is bigger than the diameter of the wire rope sling an example would be if you're using a 20 mm diameter wire rope sling the shackle attached to the wire rope sling eye must be at least 7/8 of an inch or 22 mm in diameter it is also worth noting that the European en standard requires that the object in the eye of the soft eyee sling be not less than twice the nominal diameter of the wire rope once the shackle is connected to the sling the shackle is attached to the load with the screw pin in contact with the connection point on the load as shown the screw pin is then rotated to a minimum of hand tight into the ear of the shackle body with full thread engagement before lifting or movement of the load begins the load should be centered on the shackles to prevent side loading and the screw pin must be tightened before each pick the rigging triangle is a key consideration when making connections to loads and load hooks the rigging triangle is formed any time two or more slings are connected to a load and load hook whether the slings are chain wire rope or synthetic the best practices are based on the same principles focusing on the horizontal sling angles formed in the rigging triangle highlights several best practices that are very valuable to the rigger it is important to remember that as the rigging triangle becomes flatter the horizontal sling angles become smaller as the horizontal sling angle become smaller even though the lifting load Remains the Same the crushing loads increase the sling tension is the result of both lifting and crushing this means as the sling angle becomes smaller the sling tension and the load at the load connections increase and the crushing forces pulling the slings toward the Cog also increase the result is that at 60° horizontal sling angle the sling tension is multiplied by 1.15 at 45° the tension is multiplied by 1 .41 and at 30° horizontal sling angle the tension is multiplied by two these facts lead us to recognize the best practice for selecting proper sling angles for multiple leg Bridal whether the connection is direct to the load with Hardware or choker and basket hitches a horizontal sling angle of 60° is the angle of choice this is because the multiplier is only 1.15 the side or angular load on the load connections is limited and the crushing load is minimal a tool to use to verify that the slings are rigged to 60° is to remember that a 60° sling angle is formed when an equilateral triangle is created that means that the sling lengths will be equal to the distance between pick points it is also useful to remember that increasing the sling length will increase the horizontal sling angle and improve the rigging situation it must be noted that 60° horizontal sling angle is the best choice but is also the minimum angle for single wrap chokers and single wrap baskets there are circumstances where a 60° horizontal sling angle is not possible when this occurs there are guidelines for the minimum sling angles that can be used with extreme care 45° is an acceptable horizontal Al sling angle only for bridal connected Hardware to hardware and for double WRA choker hitches at 45° the sling multiplier increases to 1.41 times the crushing forces pull the slings toward the load Center and the angular or side loading is very significant 30° is never a desirable angle however 30° horizontal sling angle can be used with extreme care care when connecting Hardware to Hardware never use choker or basket hitches at this minimal angle remember best practice calls for a horizontal sling angle of 60° or larger for all connections and hitches basket or choker single or double wrap one of the basic hitches when using wire rope slings is called the choker hitch the choker hitch is for formed when one leg of the sling connects back to itself a wire rope choker hitch does not have the full capacity of the straight leg vertical hitch the choker hitch capacity is approximately 75% of the straight leg vertical hitch this capacity assumes that the angle of Choke is at least 120° some standards such as a API RP 2D offshore environments requires slings of all types when used in a Cher hitch application to have a capacity of No More than 70% of the straight leg vertical hitch the slings capacity is reduced further if the angle of Choke is less than 120° in fact if the sling is bent back over itself with the angle of its choke approaching 0° the slings capacity would be reduced by 50% a single leg choker hitch is easy and convenient to use and can work well on simple short loads but it does not always provide the load control and grip needed for safe and effective rigging sometimes multiple leg slings choked on both ends of the load are required to gain the load control necessary if choker hitches are used the user must always ensure that the slings cannot slip or slide along the load it is important to note that a standard choker hitch does not provide a full 360° contact with the load a double wrap choker hitch is better for handling those Hard to Handle loads and bundles of material like rods or pipe that require more sling contact to hold them in place make sure the slings do not overlap at the bottom of the load when you form the double wrap choker as a final note the user should always ensure that the wire rope slings are protected from edges corners protusions or abrasive surfaces in order to protect the Sling from any damage Crosby screw pin and bolt type shackles sizes 3/16 in to 3 in can be used in side loing applications when installed correctly with the pin secure and the direction of loading is in the plane of the shackle bow as shown in Crosby's General catalog however a reduction in the shackle working load limit is required when side loading occurs it is important to point out that side loading of a round pin shackle is never allowed it is secured by a cotter pin that could Shear when s side load when the direction of pull is vertical perpendicular to the shackle pin no reduction in the shackle working load limit is required however if the shackle is subjected to a side load of 45° from vertical the shackle working load limit must be reduced to 70% of the shackle rated capacity thus when a screw pin or bolt type shackle is subjected to a 45° side load the shackle loses 30% of its published working load limit if the screw pin or bolt type shackle is subjected to a 90° side load from vertical the adjusted working load limit would be 50% of the shackle rated capacity thus when a screw pin or Bol type shackle is subjected to a 90° side load the shackle loses 50% of its published working load limit it is important to state that when a shackle is used as a collector ring to gather multiple sling legs as shown this is not considered a side loading circumstance when the slings are collected with the included angle not greater than 120° this would be considered a balanced load and the shackles working load limit would not require a reduction using two slings in a true inline load each side will see half the total weight from the Crosby lifting guide notice that for a 90° horizontal sling angle the load angle factor is one in this example the total load is 5,000 lb which which is divided by two for each sling leg and then multiplying by the load factor which is one the result is that each side lifts 2500 lb to select the proper bolt refer to the Crosby lifting guide note that the panel does not mention the s279 because the information is the same for all Crosby shoulder eyebolts we need to select an eyebolt whose working load limit exceeds the required load of 2500 lb which in this case is a 1/2 in Machinery eyebolt with an inline working load limit of 2600 lb let's now look at how increasing the horizontal angle affects the size fitting required for 60° the load angle factor is 1.55 again we divide the load of 5,000 lb by 2 and then multiply by the load factor to determine the load each sling leg will see in this case each Ling is loaded to 28875 lb we will round the calculated load to 2,888 lb referring to the lifting guide you will notice four columns showing the rated capacity of Crosby shoulder eyebolts at various horizontal angles Crosby shoulder eyebolts have a catalog rating based on inline loading as side loading occurs on the eyebolts they must be downrated the smaller the horizontal angle the greater the reduction in the working load limit as an example let's look at the/ Quin size at 90° or in line the rating is 650 lb as the horizontal angle changes so does the resulting working load limit of the eyebolt at 60° the rating is 420 lb at 45° the rating is 195 lb and at horizontal angles less than 45° the working load limit has been reduced to 160 [Music] lb
