Another safety approach

• Photo courtesy of Honeywell Safety Products, Smithfield, R.I.
• Photo courtesy of Honeywell Safety Products, Smithfield, R.I.

Fall protection is an important part of a roofing company's operations. But choosing the appropriate fall-protection system for a given job can be complicated because of the many options available. When it comes to fall protection for rooftops and other locations with potential fall risks, horizontal lifelines offer roofing professionals greater flexibility. Protecting multiple workers per system and allowing workers greater freedom of movement than single-point anchorages, horizontal lifelines provide continuous fall protection during long work sessions while permitting lateral movements across roofs—all with 100 percent tie-off.

Correct specification, installation and use of horizontal lifelines are critical to realizing the advantages of the system in terms of worker productivity and safety. Although a personal dialogue with a certified safety professional or manufacturer is the best source for recommendations and information, following is a brief checklist to get started.

Comparing configurations

Horizontal lifeline systems are offered in a variety of configurations. In its simplest form, a horizontal lifeline consists of a cable or rope attached between two anchor points on a rooftop or other elevated work area that poses a fall risk for personnel. Workers typically attach themselves to a horizontal lifeline with a lanyard. The system's sliding connection reduces the risk of dangerous swing falls, which can occur if a worker moves away laterally from a fixed anchorage.

Permanent systems are installed in a single location. Portable designs are used temporarily on a job site until work is completed then are removed. Single-span horizontal lifelines consist of a cable or rope connected between two anchor points. They are used in straight runs, are limited in length and have limitations to minimize the deflection of the line that occurs during a fall to reduce potential injury.

Multispan horizontal lifelines, supported by intermediate anchor points to reduce deflection, are not limited in length. Although some systems require attached workers to connect and disconnect across intermediates with a double-legged lanyard, more sophisticated designs feature special intermediate brackets and a shuttle, allowing users to cross the intermediate without disconnecting.

Determining requirements

The strength required for an anchor point that secures a basic horizontal lifeline—a cable or rope run from one end to the other—can be upwards of 10,000 pounds. In these cases, many horizontal lifeline systems are designed with an inline shock absorber, which is used to reduce the loads transferred to the anchor points. But even with a shock absorber, horizontal lifelines still can require anchor point strengths of 5,000 pounds.

When specifying a system, it is important to know the amount of force a horizontal lifeline system would produce in the event of a fall so you can ensure a structure is able to support the load. Fall clearance calculations should be performed to ensure there is sufficient clearance to the closest obstacle.

Some systems may require installers to penetrate a roof system's subsurface and reinforce the roof structure. More advanced systems are designed to reduce loads on a roof. These may feature shock-absorbing posts that significantly decrease forces at the anchor points and intermediates while eliminating or minimizing the need for roof system penetration.

Knowing the components

The key components of a horizontal lifeline system include a shock absorber, lifeline, turnbuckles and tension indicators. Each has a specific function to perform and must be selected and employed accordingly. Components include the following:

• Inline shock absorber. This most important part of a horizontal lifeline typically is found at one of the line's ends. It greatly reduces the fall forces transferred to a roof structure.
• Cable or rope lifeline. This commonly is a kernmantle rope or steel cable.
• Turnbuckle. This allows a worker to adjust a lifeline's tension.
• Tension indicator. Tensioning a lifeline helps minimize its deflection in the event of a fall and eases rescues if needed. However, the line should not be over-tensioned; some slack is needed to help reduce the forces exerted on the end anchors. A tension indicator allows a worker to easily determine proper lifeline tensioning.
• Fall indicator. This shows whether the lifeline has experienced a fall. If it has, it should be removed from service and inspected by a competent person.
• Intermediate supports. Without these, lifelines have a limited length (commonly 30 to 60 feet). Intermediates allow a lifeline to possess multiple spans and extend longer distances.
• End anchors. Found at the ends of a lifeline, these are its main supports.
• Shuttle or traveler. Found on more sophisticated lifelines, this allows a worker to cross intermediates without needing to connect and disconnect using 100 percent tie-off practices.
• Shock-absorbing intermediate and end posts. Even with an inline shock absorber, forces generated from a horizontal lifeline still may be too great for a roof. Some systems use shock-absorbing posts to further reduce forces transferred to a roof. These posts also eliminate or minimize the need to penetrate through a roof's subsurface for installation of posts or structural reinforcement.

Specifying the system

Similar to roofing jobs, no two applications of any fall-protection system are truly alike. Therefore, it can help to consult a professional engineering firm, particularly if you have questions about federal and local codes and regulations. When specifying a lifeline system, it's important to consider many factors, such as:

• Anchorage. To what type of roof will the horizontal lifeline be anchored? Will the roof or its structure(s) be able to support the horizontal lifeline, or will reinforcing be required? Note: Anchors must be designed as part of a complete personal fall-arrest system with a safety factor of at least 2.
• System length. What length of lifeline is required? If intermediates are necessary, will the structure support them? For shorter systems (30 to 60 feet), intermediates may not be necessary if fall clearance is sufficient and/or the roof can support the requisite forces. Longer systems may require intermediate supports.
• Bends. Does the system require any bends? Sophisticated horizontal lifelines can be designed to go around corners. This feature especially is useful when designing horizontal lifelines around roof perimeters.
• Fall clearance. What is the available fall clearance? Not all horizontal lifelines are designed the same. Some require more fall clearance than others. Some systems are designed with energy-absorbing posts that won't tip over, minimizing fall clearance and making rescue easier.
• Number of workers. How many workers will be using the line? Typically, a line can accommodate two to four workers, but some can accommodate as many as six.
• User equipment needed to complete the personal fall-arrest system. This includes shuttles, connecting devices and harnesses. For example, if there are intermediates, consider using a shuttle to cross them easily. When selecting connecting devices, lanyards are easy to use and inexpensive, and self-retracting lifelines (SRLs) minimize fall clearance. The Occupational Safety and Health Administration states a snaphook cannot be connected directly to a horizontal lifeline unless it is the locking type and designed for such a connection. Many horizontal lifelines are sold with specially designed attachment rings for this purpose.

To streamline choices during the component selection process, interactive online tools can help, and many fall-protection equipment manufacturers offer them. Online tools can lead users through the specification process, suggesting turnkey solutions to consider, procure and install.

Installation and use

First, users always must follow the manufacturer's instructions. Each system and job combination is different. A safe, proper installation demands a full understanding of the forces required by a horizontal lifeline so it can be determined whether a roof structure can support the necessary loads.

In addition, workers must understand how the system works, its proper use and how to calculate their fall clearances. User equipment also must be appropriately selected for each system and situation. Details are critical.

For instance, if a horizontal lifeline is designed for use with an SRL, the user should be aware using a lanyard instead of an SRL could result in personal injury and/or death.

Specifics also can enhance productivity. For example, when there are intermediates, a shuttle or traveler can be used with a horizontal lifeline to allow for easily crossing over intermediates. And though most harnesses may be compatible with horizontal lifelines, harness selection must be appropriate to an application's individual requirements.

As with all personal protective equipment, it is essential horizontal lifelines be inspected according to the manufacturer's instructions. In addition to an annual inspection of the system by a certified individual, workers should inspect their systems and equipment before each use. Among the items to review, workers should:

• Check to make sure the fall indicator is not activated. If it is, the system should not be used.
• Ensure there are no extensions, deformities or indications of a previous fall on the shock absorbers.
• Make sure the horizontal lifeline cable is free of kinks.
• Check the rope and webbing for excessive fraying and discoloration.
• Ensure equipment is free of rust.
• Make sure the shuttles and snap hooks function properly.

The bottom line

Traditional fall-protection systems can be costly, requiring extensive design and engineering work plus installation by certified professionals. These systems also may require penetrating a roof system's surface and structural reinforcement.

Rooftop horizontal lifelines offer options. Surface-mounted horizontal lifeline solutions allow a 50 percent reduction in labor and cost versus a conventional roof-penetrating post system. New do-it-yourself kits can make installations even easier and less costly. In all, properly specified, installed and deployed horizontal lifelines provide roofing professionals with an alternative fall-protection solution that can enhance productivity and reduce costs without compromising safety.

Alex Tsen, P.Eng., is product marketing manager, anchorage systems for Honeywell Safety Products, Smithfield, R.I.

For articles related to this topic, see:
"Solar safety," October 2013 issue
"Falling for safety," March 2013 issue
"Calculated clearance," June 2008 issue

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