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 roofsall 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.
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.
The strength required for an anchor point that secures a basic horizontal lifelinea cable or rope run from one end to the othercan 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:
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:
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:
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.