Published on: October 23, 2013
Horizontal lifeline systems are an important component of modern fall protection implementations and are generally categorized as rigid or flexible.
Rigid horizontal lifeline structures are usually permanent additions to buildings and provide solid anchorage points for individual fall protection equipment. Workers can secure their own personal lifelines to the pipe or rail and move along these rigid support systems safely and securely.
Flexible horizontal systems, by contrast, consist of a pliable lifeline that is securely attached to two or more anchorage points. Workers then attach their personal fall protection lifelines and equipment to the lifeline, allowing them to proceed safely along the length covered by the flexible horizontal lifeline.
Horizontal lifeline systems can provide added mobility for workers by allowing them to move safely and easily along the length of these temporary or permanent fall protection systems. This can increase productivity and reduce the need for repeated attachments and re-attachments to various anchorage points as workers move around the work area. These complex fall protection systems, however, must be installed to precise specifications due to the heightened degree of stress placed on horizontal rails and lines in the event of a fall.
Factors that Affect Protection in Horizontal Lifeline Systems
In a standard horizontal lifeline system, the worker’s personal fall protection equipment connects directly to the overhead horizontal line. As the worker moves along a lower parallel to the horizontal lifeline, the point of anchorage for the personal equipment slides along that lifeline and maintains contact directly overhead. In the event of a fall, this ensures that the worker descends a small distance, directly below the lifeline anchorage. If the worker’s anchorage is not directly overhead, a swing fall can result; these dangerous accidents can cause a pendulum movement in the worker’s lifeline that can result in contact with construction equipment, building components or other objects. By ensuring that workers are securely attached directly overhead to the horizontal lifeline, the lifelines can reduce this significant risk to employees in elevated areas.
Single-Span Horizontal Systems
As the name suggests, single-span horizontal lifeline systems cover a limited area and are secured by two anchorage points. They are typically intended to allow freedom of movement across a building wall or other elevated area. Rigid single-span horizontal installations are generally permanent fixtures on the building or above work areas and are sometimes installed during the initial construction. Because rigid fall protection systems do not sag or give way, calculating the strength required for these systems is simplified to a significant degree. These systems typically must be capable of sustaining loads of five tons or more in normal use. Flexible horizontal lifelines may be constructed of steel cables or other high-tensile-strength materials. Because these lifelines typically exhibit at least some degree of elasticity, they may require even higher weight tolerances to provide effective protection in these systems. The two anchorages at the end points must also be rated for adequate weight tolerances to ensure worker safety.
Multi-Span Horizontal Systems
Multi-span horizontal lifeline systems are connected at various anchorage points along the length of the fall protection system. These added points of connection to the building allow these systems to cover an extended area of the building and can provide added security for workers in these elevated areas. Multi-span systems can be rigid or flexible and are subject to the same requirements as single-span horizontal lifeline systems; they must have appropriate weight tolerances and must arrest falls within six feet or less from where the fall initially occurred. Some multi-span horizontal systems can be designed to go around corners or obstructions. In all cases, single-span and multi-span fall protection systems should be produced and installed by trained professionals in this field to ensure safety for workers.
Horizontal lifeline inspection procedures are required by OSHA regulations to maintain safe working conditions. Additionally, care must be taken with personal fall protection systems to ensure that workers are protected in construction, building maintenance and elevated work area environments.