Fall arrest solutions require attention to detail, not scale

Implementing a fall protection system, regardless of size, requires considering a number of factors to ensure optimal worker safety.

03/14/2013


Proper fall arrest systems allow workers to move safely and unencumbered during the equipment construction. Courtesy: GorbelBig or small, implementing a fall protection system requires considering a number of factors. To prove operation size has no bearing on the installation, let’s take a look at a truly large-scale operation.

A company building track trenching and surface mining machines was recently faced with the challenge of ensuring a safe work environment for those assembling the machines. Assembling one machine takes about eight weeks and requires moving very large, heavy components using 40-ton-capacity overhead bridge cranes.

With each machine weighing nearly 200 tons and with a grinding surface almost 10 ft tall and treads as tall as a man, the machines presented a less-than-straightforward solution for safety. It doesn’t take long before the assembly process reaches a point where workers are working at heights that put them at risk for potential falls. Lucky for the assemblymen, the company building the machines had safety in mind.

Because of the complicated assembly, any form of passive restraint—such as handrails—is impractical. While the company initially sought a permanent overhead fall arrest system, it quickly realized that most permanent solutions to protect the workers from falls would become obstacles for the cranes delivering components to those workers.

The company in this example followed the same process for identifying the right fall protection that practically any company, large or small, should. Let’s examine the five key points: 

1. The 4-foot rule, or do I need protection? The 4-foot rule refers to Section 29 of the Code of Federal Regulations (29 CFR). OSHA enforces safe and healthful working conditions for general industry, construction, and maritime trades. Employers have the duty of providing their workers with a place of employment free from recognized safety and health hazards.

OSHA enforces regulation 1926, Subpart M for construction and regulation 1910, Subparts D and F for general industry, which require fall protection be provided at: 4 ft in general industry; 5 ft in shipyards; 6 ft in the construction industry; 8 ft in longshoring operations; and any height when working over dangerous equipment or machinery. If you have any of these conditions, then you’re legally required to implement a suitable fall protection system.

2. Elimination or protection? Once a fall hazard has been identified, there are essentially two options: eliminate the hazard or protect against it. In some cases, it is possible to eliminate a fall hazard, typically known as “engineering out the hazard,” simply by changing the working environment, processes, and procedures. If this is not possible, fall prevention should be the next consideration.

Common fall prevention methods include installing guardrails, scaffolds, handrails, or barriers. When passive fall protection solutions such as elimination or prevention are not practical, personal fall protection equipment, such as harnesses, lanyards, and retractable lifelines, can be used. Personal fall protection may consist of a restraint system to keep the worker from reaching an area where a fall hazard exists, or a personal fall arrest system that enables a worker to perform his duties from the height required while tied off to the system.

A restraint system prevents the worker from falling at all. It restrains the worker by fitting him in a harness with a tether attached. A fixed-length lanyard is then attached to the D-ring on the harness, and then to a code-compliant anchorage system. Restraint is typically the preferred fall protection system when the environment allows for it, because a fall is completely avoided. However, there are many environments where it’s not optimal. Restraint systems don’t tend to be very flexible once they’re in place, they don’t always handle multiple workers well, and the length of the system may be limited.

Fall arrest systems allow the worker to fall, just not very far. The systems are typically professionally engineered, ideally custom designed for the specific work environment.

3. The ABCs of a fall arrest system. There is an easy way to remember the components of a proper fall arrest system—the ABCs of fall arrest:

  • Anchorage
  • Body support
  • Connectors

Anchorage is a secure point to attach a lifeline, lanyard, deceleration device, or any other fall arrest or rescue system. These include structural steel members, precast concrete beams, and wooden trusses. An anchorage connector (or an anchor) is a piece of equipment used as a safe means to attach the lanyard or lifeline to the anchorage, such as cable and synthetic slings, roof anchors, and beam clamps.

Proper body support in a fall arrest system is a body harness. A body harness provides a connection point on the worker to distribute the forces evenly across the body in the event of a fall. A full body harness is a body support device that distributes fall arrest forces across the shoulders, thighs, and pelvis and has a center back fall arrest attachment for connection to the connecting device.

Connectors include lanyards, snap-hooks, carabineers, deceleration devices such as self-retracting lanyards (SRLs), vertical and horizontal lifelines, ladder climbing systems, and rope grabs. SRLs have developed into an excellent technology. An SRL is a deceleration device containing a drum-wound line that may be slowly extracted from or retracted onto the drum under slight tension during normal movement.

After onset of a fall, it automatically locks the drum and arrests the fall within 3-1/2 ft (which meets both OSHA and ANSI standards). SRLs work much like a car seat belt. The devices are meant to be anchored directly above the worker and reduce the free fall of the worker as well as swing fall—the distance a worker swings from side to side as he or she falls.

Fall arrest systems should be situated so that workers can safely access all areas of the equipment, and also be easily repositioned for maximum production flexibility. Courtesy: Gorbel4. Wire rope vs. rigid rail. In fall arrest there are two types of systems: those that use a wire rope to support a worker and those that use a rigid rail. Rigid rail systems, while slightly more expensive in initial installation, are a superior choice for several reasons.

Wire rope systems require additional fall clearance due to the initial sag of the wire. The dynamic sag, or the stretch of the rope during a fall, adds to this distance.

Rigid rail fall arrest systems stop the fall sooner by eliminating any sag, stopping the fall in a much shorter distance than wire rope. Injuries occurring after the fall, such as swinging into obstacles, are minimized with a rigid rail fall arrest system, which stays firm and minimizes the total fall distance. When a worker falls on a wire rope system, the wire’s sag will make the trolley slide to the center of the nearest two supports, creating a risk for the worker to collide with nearby obstacles after a fall.

A rigid rail fall arrest system allows for longer distances between supports, reducing both material and installation costs. When a worker falls on a wire rope system, any slack on the wire is eliminated. The result could be a sudden pull on the rope that could have a jarring effect on other workers on the same system. Rigid rail fall arrest systems provide uninterrupted protection for additional workers on the same system.

In the event of one worker’s fall, the rigid rail system will not bend or deflect like a wire rope system, allowing additional workers to continue to move freely and safely. The worker can continue use of a rigid rail fall arrest system after a visual inspection. A wire rope system must be replaced and recertified by a qualified engineer.

5. Rigid flexibility. While the name might imply otherwise, rigid rail systems are the most flexible forms of fall arrest. Ideal for environments where there is limited clearance between the working level and lower level or obstruction, these systems provide a shorter free-fall distance and a reduced risk of secondary injury due to impacts during the free fall or sudden deceleration. Rigid rail fall arrest systems are the perfect solution for permanent applications and can easily be customized to fit every situation.

Fall arrest systems are now available in multiple configurations, including various track profiles and support center distances, and can be easily customized to fit every budget and application. If you have determined a fall protection need, add fall protection to the company’s overall health and safety plan.

A written site-specific program should be developed, including detailed work procedures to protect your employees. The fall protection portion of your plan should state what fall protection measures are to be used, how they are to be used, a rescue plan, as well as the individual responsible for overall supervision and training.

Remember these five points and you’re on your way to a safer workplace. 

Kevin Duhamel is a North American product manager with Gorbel Inc. Kevin has more than 15 years of safety industry experience and expertise and has specialized in fall protection since 2008. He is a certified fall protection–competent trainer and inspector.



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