11-2 Fall Protection

SCOPE

This guide refers to safe usage of body harnesses. As with most other types of personal protective equipment, a safety harness is worthless unless it is worn at the time of the need. The following guide indicates typical situations where safety harnesses would be utilized.

DEFINITIONS

“Anchorage” means a secure point of attachment for lifelines, lanyards or deceleration devices, and which is independent of the means of supporting or suspending the employee.
“Body harness” means a design of straps which may be secured about the employee in a manner to distribute the fall arrest forces over at least the thighs, pelvis, waist, chest and shoulders with means for attaching it to other components of a personal fall arrest system.
“Declaration device” means any mechanism, such as a rope grab, rip stitch lanyard, specially woven lanyard, tearing or deforming lanyard, or automatic self retracting-lifeline/lanyard, which services to dissipate a substantial amount of energy during a fall arrest, or otherwise limits the energy imposed on an employee during fall arrest.
“Deceleration distance” means the additional vertical distance a falling employee travels, excluding lifeline elongation and free fall distance, before stopping from the point at which the deceleration device begins to operate. It is measured as the distance between the location of an employee’s body harness attachment point at the moment of activation (at the onset of fall arrest forces) of the deceleration device during a fall, and the location of that attachment point after the employee comes to a full stop.
“Free fall” means the act of falling before the personal fall arrest system begins to apply force to arrest the fall.
“Free fall distance” means the vertical displacement of the fall arrest attachment point on the employee’s body belt or body harness between onset of the fall and just before the system begins to apply force to arrest the fall. This distance excludes deceleration distance, lifeline and lanyard elongation but include any deceleration device slide distance or self-retracting lifeline/lanyard extension before they operation and fall arrest forces occur.
“Snap-hook” means a connector comprised of a hook shaped member with a normally closed keeper, or similar arrangement, which may be opened to permit the hook to receive an object and, when released, automatically closes to retain the object. Snap-hooks are generally one of two types:

The unlocked an depressed open for connection or disconnection, or
The non-locking type with a self-closing keeper which remains closed until pressed open for connection or disconnection.

Component Design

Connectors shall have a corrosion-resistant finish, and all surfaces and edges shall be smooth to prevent damage to interfacing parts of the system.
NOTE: Although not required by this standard for all connections, locking snap-hooks designed for connection to suitable objects (of sufficient strength) are highly recommended in lieu of the non-locking type. Locking snap-hooks incorporate a positive locking mechanism in addition to the spring loaded keeper, which will not allow the keeper to open under moderate pressure without someone first releasing the mechanism. Such a feature, properly designed, effectively prevents roll-out from occurring.

The following connections must be avoided (unless properly designed locking snap-hooks are used) because they are conditions which can result in roll-out when a non-locking snap-hook is used

direct connection of a snap-hook to horizontal lifeline
two (or more) snap-hooks connected to one dee-ring
two snap-hooks connected to each other
a snap-hook connected to a webbing loop or webbing lanyard
improper dimensions of the dee-ring, rebar, or other connection point in relation to the snap-hook dimensions which would allow the snap-hook keeper to be depressed by a turning motion of the snap-hook

Lanyards and vertical lifelines which tie-off one employee shall have a minimum breaking strength of 5,000 pounds.
Self-retracting lifelines and lanyards which automatically limit free fall distance to two feet (0.61m) or less shall have components capable of sustaining a minimum static tensile load of 3,000 pounds applied to the device with the lifeline or lanyard in the fully extended position.
Self-retracting lifelines and lanyards which do not limit free fall distance to two feet (0.61m) or less, rip stitch lanyards, and tearing and deforming lanyards shall be capable of sustaining a minimum tensile load of 5,000 pounds applied to the device with the lifeline or lanyard in the fully extended position.
Dee-rings and snap-hooks shall be capable of sustaining a minimum tensile load of 5,000 pounds.
Ropes and straps (webbing) used in lanyards, lifelines and strength components of body harnesses, shall be made from synthetic fibers or wire rope.

Fall Arrest Systems

Personal fall arrest systems shall, when stopping a fall:

limit maximum arresting force on an employee to 1,800 pounds (8kN) when used with a body harness
bring an employee to a complete stop and limit maximum deceleration distance an employee travels to 3.5 feet (1.07m); and
shall have sufficient strength to withstand twice the potential impact energy of an employee free falling a distance of six feet (1.8m) or the free fall distance permitted by the system, whichever is less.

Positioning Systems

A positioning system holds a worker in place while allowing a hand-free environment. A fall arrest device should be used in conjunction with a personal positioning system. The maximum free-fall distance is 2 feet when in a positioning system.

NOTE: Effective January 1, 1998, body safety belts are not acceptable as part of a personal fall arrest system. The use of a body safety belt in a positioning device system is acceptable.

Care and Use

Snap-hooks, unless of a locking type designed and used to prevent disengagement from the following connections, shall not be engaged:

directly to webbing, rope or wire rope;
to each other;
to a dee-ring to which another snap-hook or other connector is attached;
to a horizontal lifeline; or
to any object which is incompatibly shaped or dimensioned in relation to the snap-hook such that the connected object could depress the snap-hook keeper a sufficient amount to release itself.

Personal fall arrest systems shall be rigged such that an employee can neither free fall more than six feet (1.8m), nor contact any lower level.
The attachment point of the body harness shall be located in the center of the wearer’s back near shoulder level, or above the wearer’s head.
When vertical lifelines are used, each employee shall be provided with a separate lifeline.
Personal fall arrest systems or components shall be used only for employee fall protection.
Personal fall arrest systems or components subjected to impact loading shall be immediately removed from service and shall not be used again for employee protection unless inspected and determined by a competent person to be undamaged and suitable for reuse.
The employer shall provide for prompt rescue of employees in the event of a fall or shall assure the self-rescue capability of employees.

Inspections

Personal fall arrest systems shall be inspected prior to each use for mildew, wear, damage and other deterioration, and defective components shall be removed from service if their strength or function may be adversely affected.

Employee Training Considerations

Before the equipment is used, employees must be trained in the safe use of the system. This should include the following: 1) application limits; 2) proper anchoring and tie-off techniques; 3) estimation of free fall distance, including determination of deceleration distance, and total fall distance to prevent striking a lower level; 4) methods of use; and 5) inspection and storage of the system.

Careless or improper use of the equipment can result in serious injury or death. Of uppermost importance is the reduction in strength caused by certain tie-offs (such as using knots, trying tying around sharp edges, etc. and maximum permitted free fall distance. Also, to be stressed are the importance of inspections prior to use, the limitations of the equipment, and unique conditions at the worksite which may be important and determining the type of system to use.