Solution Summary: Work Positioning System
A work positioning system is a personal fall arrest system, an engineering control, that limits the distance of free fall to two feet or less which reduces the risk of injury due to a fall to a lower level. The system consists of an anchor, a body harness (or belt) and a lanyard specifically designed for positioning. This type of fall protection is most often utilized while on elevated vertical surfaces such as walls or poles where employees need to use both hands while working.
Work positioning systems are used in select work areas, such as formwork or installation of reinforcing steel. These areas require the employee to work at vertical elevations without a platform. Work positioning systems are not designed for horizontal surfaces; such as scissor lifts or boom-type elevated work platforms. Although work positioning systems use much of the same equipment as personal fall protection systems, the purpose and function of work positioning systems differ slightly. A work positioning system supports an employee while working at elevations, in addition to protecting the employee from falls. The positioning system creates one additional risk when compared to a traditional personal fall arrest system, which is that if a positioning system fails the employee will fall to a lower level. This risk could occur with a traditional personal fall arrest system, but more likely the deficient equipment will be identified during daily inspections or during use, but will not be under a constant load securing the employee.
A work positioning system is defined by OSHA as “a body belt or body harness system rigged to allow an employee to be supported on an elevated vertical surface, such as a wall (or a pole), and work with both hands free while leaning.” These systems are composed of anchorage, connectors, and body support. These systems will limit the fall of an employee to 2 feet. Throughout the duration of use of a work positioning system, tension will be kept at all times in the life safety ropes that the employee is attached to. Slack in the positioning lanyards is also kept at a minimum to decrease the falling distance in the case of an incident. When using a work positioning system, the employee should also use a personal fall protection system as a secondary backup option in case the work positioning system fails. The work positioning system is the primary system, with a fall arrest system acting as the secondary system to aid in fall prevention in the case of a primary system failure. This is a crucial component of a work positioning system since these systems are not designed for protection.
Two basic types of work positioning exist: equipment to lean from and equipment to be suspended from. These systems support a person’s weight and tools so their hands are free for work. Positioning systems will also aid in maintaining the balance of the employee, which helps to prevent falls. Although these systems can aid in the prevention of falls, they are not considered to be fall arrest systems.
Bridge painter using a work positioning system (http://elcosh.org)
General Requirements for Positioning Systems
- Positioning devices must be rigged such that an employee cannot free fall more than 2 feet.
- Positioning devices must be secured to an anchorage capable of supporting at least twice the potential impact load of an employee's fall or 3,000 pounds, whichever is greater.
- Connectors must be drop forged, pressed or formed steel, or made of equivalent materials.
- Connectors must have a corrosion-resistant finish, and all surfaces and edges must be smooth to prevent damage to interfacing parts of this system.
- Connecting assemblies must have a minimum tensile strength of 5,000 pounds.
- D-rings and snaphooks must be proof-tested to a minimum tensile load of 3,600 pounds without cracking, breaking, or taking permanent deformation.
- Only locking type snaphooks should be used.
Unless the snaphook is designed for the following connections, snaphooks must not be engaged:
- Directly to webbing, rope or wire rope.
- To each other
- To a D-ring to which another snaphook or other connector is attached
- To a horizontal lifeline
- To any object in which its shape or dimension is incompatible in relation to the snaphook such that unintentional disengagement could occur by the connected object being able to depress the snaphook keeper and release itself.
- Positioning device systems must be inspected prior to each use for wear, damage, and other deterioration, and defective components must be removed from service.
- Positioning systems and components must be used only for employee protection and not to hoist materials.
The positioning device of a window cleaner must be capable of surviving a drop test consisting of a 6 foot (1.83 m) drop with a weight of 250 pounds (113.4 kg). The system must also limit the initial arresting force to no more than 2,000 pounds (8.9 Kn) within 2 milliseconds, and any subsequent arresting forces imposed on the falling employee to no more than 1,000 pounds (4.45 Kn).
The positioning device of any other worker must be capable of surviving a drop test consisting of a 4 foot (1.22 m) drop with a weight of 250 pounds (113.4 kg).
Formwork and Reinforcing Steel
Employees on the face of reinforcing steel must be protected from falling when exposed to a fall of 6 feet or more by personal fall protection, safety net systems, or positioning systems. However, because it would create a greater hazard for workers having to constantly connecting and disconnect fall protection devices while climbing, workers while constructing rebar assemblies are allowed to climb without fall protection up to 24 feet. Once the worker reaches their work location, or climbs above 24 feet, they must then use fall protection.
When a worker is required to work on an unprotected vertical surface, a properly designed work positioning system can provide a safe means to perform the work and prevent a worker from falling more than 2 feet, which could result in injury or death. Work positioning systems provide a safe means to perform work by requiring the employee to connect one end of their positioning lanyard to a secured anchor point and the other ends to their harness. When the employee is secured in place, they can stabilize their position with the feet against the vertical surface and have their hands free to work. A properly used positioning system can result in a fall of less than 2 feet, which can result in minor injuries. If the positioning system failed during use the employee would then fall to the lower level. The safe work practice recommended to eliminate this risk is for the employee to use an additional (back-up) connector such as a retractable lifeline, vertical lifeline or shock absorbing lanyard connected to the center back D-Ring of the full body harness and to an adequate anchor point.
How Risks are Reduced:
Work positioning systems are designed to support and suspend a worker from an elevated vertical surface. The worker is supported by connecting one end of their lanyard to their body harness and the other end to a secured anchor point. This will allow the worker to remain in a working position with both hands free. The worker will feel secure in their position and secondary back up fall protection measures should also be used, such as a fall arrest system, to add extra protection in the instance a fall should occur.
Work positioning systems can be used when traditional methods of fall protection are not feasible to use for assigned work tasks on a vertical surface. Work positioning systems allow workers to utilize proper work positions and still maintain a hands free stature. This hands free positioning allows workers to complete their job tasks properly, as many work tasks require the use of both hands to be accomplished effectively and safely.
OSHA regulates positioning devices systems under 1926.502(e) and the American National Standards Institute (ANSI) has an industry recognized standard, Z359.3 Safety Requirements for Positioning and Travel Restraint Systems.
J. Nigel Ellis Pd.D., P.E., CSP, CPE is a leading authority in the field of industrial fall protection and has helped developed OSHA standards for fall protection and has a member of ANSI, ASTM, SAE and ISO. Dr. Ellis's 4th edition to Fall Protection provides guidance and direction on Work Positioning Systems.
Effects on Productivity:
While there is very little information on productivity from manufacturers or independent studies, safety and health experts believe the use of work positioning systems will lead to an increase in productivity. This is due to the fact that work positioning systems allow employees to work with both hands while the positioning system keeps them in place thus providing the employee sense of security from falling allowing them to concentrate on the work at hand.
Equipment Mixing and Mismatching
Not all components of a system are interchangeable and no components of a work positioning system should be substituted or changed without first being fully evaluated by a competent person or the equipment manufacturer. It is recommended that a complete work positioning system be purchased from a reputable manufacturer prior to use.
Equipment Inspection and Storage
Work positioning equipment should be inspected before each use to ensure proper working condition. Typical wear and tear should be inspected for, such as fraying, kinking, knotting, and pulled stitches. Chemical damage, discoloration, sharp edges, and cracks should also be inspected for. If any equipment is found to be damaged, the equipment should be marked “Do Not Use” and removed from service. The instructions provided by the manufacturer should be followed for inspection.
Work positioning equipment must also be properly stored according to the manufacturer’s instructions. Equipment should be stored away from heat, light, dampness, oil, chemicals, or other conditions that could alter the integrity of the equipment.
Fullen, Mark, CSP, Savage, Kristen and Coffield, Lindsey - West Virginia University
Miller Fall Protection
To obtain information, visit www.millerfallprotection.com or contact 1-800-873-5242
MSA, The Safety Company
To obtain information, visit https://us.msasafety.com/ or contact 1-800-672-2222
Guardian Fall Protection
To obtain information, visit www.guardianfall.com or contact 1-800-466-6385