Month: <span>September 2019</span>

You may encounter many terms when reviewing rope and cable specifications. Sometimes these terms may be used in confusing ways. For example, “strength” may be used to describe “tensile strength” or the completely different concept of “yield strength.” Here is an overview of some terms you may see in rope and cable descriptions:

Strength

Generally, strength refers to the amount of stress a material can bear before its properties change. “Yield strength” is the stress that causes a material to transition from elastic deformation (deformation from which the material can recover) to plastic deformation (deformation that permanently deforms the material). Thus, ropes and cables will “bounce back” after a load below the yield strength, but will be permanently stretched after a load above the yield strength.

“Tensile strength” or “ultimate strength” means the maximum load a material can withstand. The tensile strength is generally greater than the yield strength because materials can usually withstand additional loads even after reaching a plastic state. However, once the tensile strength is reached, deformation of the material concentrates stresses and ultimately results in fracture.

“A chain is only as strong as its weakest link,” so remember to account for the strength of knots, fittings, and rigging. Knots can reduce the tensile strength of cable and rope by as much as 50% because the knot compresses and deforms the cable or rope. Similarly, turnbuckles, such as toggle turnbuckles, can shear or fracture below the tensile strength of the rope or cable. Moreover, even though the pin of a toggle turnbuckle may relieve torsion shear, bearing shear remains a potential failure mode.

Abrasion Resistance

Abrasion occurs when two parts wear against one another. In the case of lifting slings, abrasion can occur when rope or cable wears against itself, a load, or rigging. General statements can be made about rope and cable materials – metal wire resists abrasion better than polymer fibers and natural fibers. However, specific values are difficult to find because abrasion depends on a number of variables, including:

• Load
• Material properties of both materials
• Wire or fiber diameter
• Surface shape and roughness

For example, a smooth round metal pin of a toggle turnbuckle would cause less wear to rope than a rough or sharp edge.

Fatigue

Fatigue is a failure mode that results from cyclical loading and unloading. Fatigue is less of a concern in applications where cables or wires are replaced after being subjected to impact or stress. For example, cable railings used for vehicle barriers may be replaced at the OSHA mandated height of 42 inches, plus or minus three inches, after being impacted. In this case, the cables would never experience cyclical loading.

However, most other applications experience some amount of fatigue. A common source of cyclical loading comes from the vibration of motors or engines in contact with ropes or cables. In maritime applications, waves or wind can subject lines to cyclical stress. Similarly, various types of lifting slings can be subjected to cyclical stress by swinging loads.

Fatigue creates micro-cracks that weaken the material and create sites for stress to concentrate. Under repeated loading, the micro-cracks grow and eventually lead to fracture. And again, do not forget that rigging, such as toggle turnbuckles, can fatigue as well.

Heat Resistance

Heat resistance is relevant for two reasons:

1. Heat can alter material properties; metal tends to soften, and plastic tends to melt, under heat
2. Heat combined with load can cause creep; creep is a phenomenon where failure can occur due to heat plus a load even when the amount of heat or load by itself would not cause failure

Corrosion

Corrosion occurs when metals in contact with one another in the presence of an electrolyte undergo chemical change to reach a more stable form. For example, metals containing iron will oxidize in the presence of oxygen ions in water. Applications requiring metal rope are prone to corrosion because water can work its way between the wires and core of metal rope or between the metal rope and its rigging. Polymer rope does not suffer corrosion, although other environmental conditions, such as exposure to chemicals, ultraviolet light, and heat, can cause material degradation.

In sum, understanding the failure modes and the descriptions used for cable and rope can help you select the right cable or rope for your particular application.

As much as American employers have made important steps towards better conditions for their workers and making the workplace safer, there are still lots of concerns regarding hazardous work environments. In 1971, OSHA published its fall protection measures, meant for general industry regulations. These regulations forced specific requirements into the workplace, and if observed perfectly, they usually greatly cut down on the risk of injury at work. Of course, while actions at the workplace often have the greatest impact on employee safety, the specific products used by employees can also have a significant impact on injury risks. Combined with the improper observation of regulations, subpar equipment is perhaps one of the greatest contributors to the risk of injury. With that being said, let’s take a deeper look into safety at the workplace, and how everything from the use of chain slings versus other types of lifting slings to the types of guard rails implemented can strengthen or weaken employees’ safety.

OSHA Regulations: How Important Are They?

OSHA was established in 1970, and its primary purpose is to keep workers safe and healthy. While everyone is expected to follow OSHA regulations, some employers neglect them, whether on purpose or by pure accident. No matter the reason, it is important for employees to report unsafe working environments. Even if you aren’t worried about your individual safety, other employees may be at risk. On that same note, you as an employee are expected to follow OSHA regulations. Even the seemingly minor regulations can have a major impact on workers’ safety. For example, guardrail openings being specifically required to not be wider than 19 inches and taller than 42 inches may seem arbitrary, but OSHA has performed specific tests to determine these requirements. For that matter, if you don’t follow OSHA regulations, you may very well be at risk of losing your job. Of course, the equipment you use, particularly when it comes to cable and rigging supplies, can also affect safety standards at work.

Lifting Slings: What Should You Use?

There are a number of different types of lifting mechanisms that you may have encountered at the workplace. However, chain slings offer a number of different advantages, not least of all the fact that they are often the safest to use. Chain slings are reliable, and can be used to lift incredibly heavy objects without breaking. The makeup of chain slings allows them to remain relatively flexible, and their makeup means that they can withstand an incredible amount of heat. A major risk that comes with lifting heavy objects is the sling itself breaking — which can injure or kill any employees in the vicinity. However, a chain sling allows workers to do what they need to do without the risk of the sling itself buckling under the pressure.

Cable Rail Fittings: Monitoring Them For Safety

Cable rails are standard in many workplaces. These railings are flexible, and often valued due to the fact that they can easily be seen through, and do not obstruct views. However, if not properly fitted these railings can produce hazardous conditions. Due to the force applied to the end posts of the railings, they must be made with very rigid frames. Furthermore, the cables themselves must have a great deal of tension, but not without giving up their flexibility. Any sort of slack in the cables, or instability in the frames, should be immediately reported and mended. Otherwise, they could give out and result in injury or even death.

Ultimately, you must hold yourself responsible for reporting any issues at your workplace — whether they’re in the construction of railings, the types of slings used to lift heavy objects, or more. It doesn’t particularly matter what the problem is; it simply must be reported. Keep in mind that thanks to OSHA, you’ll haven regulation expectations on your side. Safety first isn’t just a rule for kids to follow. You should take it seriously as well.

Safety always has to be a priority with rigging. Your rigging is only as good as your cable and rigging supplies. Safety starts with high-quality cable and rigging supplies from a trusted supplier. The right supplier will have the well-made cable and rigging supplies that you can count on.

Reliable safety protection equipment is a must. It helps reduce the risk of injury and keeps your business compliant with the OSHA laws. OSHA is constantly monitoring and tightening the laws to try to help keep people safe. They are even instituting new laws that will require ladder safety systems to be installed on all ladders that extend 24 feet or more.

High Quality Supplies Make for a Safer Rig

When it comes to rigging supplies, quality matters. Well-built supplies mean a well-built rig. There are a few things you can look for to ensure that you are dealing with a reliable supplier that does not compromise on quality:

• The supplier has a positive reputation
• They specialize in these types of supplies
• They deliver added value perks like fast turn around times on all orders

A supplier with a positive reputation earned that reputation by treating their customers well and providing the high-quality supplies that they can depend on. Enough cannot be said about choosing the established supplier with a positive reputation.

They are Specialists

When you buy cable railing hardware, cable rail fittings or rigging supplies from a company that specializes in these supplies and equipment you get the expert input that you need. There is nothing worse than ordering critical supplies and not being able to get a straight answer. Getting the expert support that you need is one of those added-value effects of turning to a firm that specializes in this type of equipment and supplies.

You Get Your Order Fast

Another one of those added-value benefits that you get when you are dealing with a firm that specializes in cable and rigging supplies is that they often have exactly what you need on hand so you get your order fast! You do not have to wait weeks to get your order.

Turn to the supplier that can meet all your rigging and cable needs!