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Anchor point

For our purposes, we will only refer to an ‘anchor point’ that will be used for fall arrest devices (as opposed to fall restraint or for horizontal lifelines). The anchorage to which the SRL is attached must be capable of sustaining static loads in the directions applied by the personal fall arrest system of at least 3,600 lbs. with certification of a qualified fall protection safety engineer, or 5,000 lbs. without certification. When more than one personal fall arrest system is attached to the same structure, the strength requirements stated above must be multiplied by the number of personal fall arrest systems attached to the structure.


Swing fall

A ‘swing fall’ occurs when the anchorage point being used in your fall protection system is not directly overhead. When a fall occurs and your descent towards the ground begins, gravity is going to try and straighten out the path between the anchor point and the ground, with you in the middle. If you have an obstruction between you and that point, you will run into it. Depending on the angle and distance you have fallen, it is likely that this impact may be severe. This pendulum action will occur very fast, too fast for you to have any meaningful effect on the outcome. The self retracting lifeline or lanyard may be able to successfully manage the deceleration from the fall, but will have no effect on the side impact hazards that may be present.


Qualified Person

A ‘Qualified Person’ has the training and experience to recognize hazards in the workplace, and is familiar with company safety procedures. This person is usually the on-site safety resource, and typically reports to the ‘Competent Person’.


Competent Person

The term ‘Competent Person’ is used in many OSHA standards and documents. As a general rule, the term is not specifically defined. In a broad sense, an OSHA 'Competent Person' is an individual who, by way of training and/or experience, is knowledgeable of applicable standards, is capable of identifying workplace hazards relating to the specific operation, is designated by the employer, and has authority to take appropriate actions. This last line is important. The 'Competent Person' must be able to step forward and stop an operation that is observed to be unsafe in some way. Additionally, the 'Competent Person' should be involved in designing workplace safety procedures.


Roll out

The term ‘roll out’ refers to a hook or carabiner becoming disconnected when interacting with an incompatible device. If a hook is snapped onto a ring with too small of a diameter, the hook can get bound up if pulled in the wrong direction. This will cause a side load on the gate opening of the hook. Most hooks are unable to resist the potential forces, and the hook disconnects. This can happen in the blink of an eye. Newer hooks that comply with the 2007 ANSI Z359 standard have reinforced gates to address this problem. However, ensuring that compatible connections are made is the user's responsibility. If there is any doubt, please contact us, a 'Competent Person' or the manufacturer.


Tag line

For our purposes, a ‘tag line’ is a length of cable, webbing or rope used to extend access to the snap hook of a self retracting lifeline. In many cases, an SRL is mounted overhead at such a distance that you can not reach it. The tag line forms a link between the work surface (which may or may not be the ground) and the SRL. When ready to commence work, pulling down on the tag line will bring the snap hook of the SRL within reach, where it may be attached to your full body harness. When you are done, reattach the tag line and gently allow the cable and hook to be recoiled back in to the SRL.


Reserve lifeline

On a self retracting lifeline, the ‘reserve lifeline’ refers to several additional turns of cable, webbing or rope left on the spool when the ‘end’ is reached. This additional length is there solely to ensure that the connection between the lifeline and the spool remains strong and intact. Some inferior designs attempt to save money by skimping on the lifeline or the mechanical means of stopping the line short of being fully extended. The stated length does not include this reserve.


Fall distance

With ‘fall distance’ we are referring to the amount of distance below you that must be allowed to avoid hitting an obstruction or the ground. This starts with the anchor point in the case of a lanyard, or the snap hook in the case of a self retracting lifeline. For our purposes, we will only be referring to a SRL. When a fall occurs, some amount of line will pay out as you start to pick up speed. Once you reach 4 feet per second or so, the brakes engage. This may take 12” to occur. Then, depending on the user’s weight, the energy absorbing mechanism may take up to 42” to bring you to a complete stop. This hypothetical 54”, added to your body’s height (e.g. 5’ 10”) gives you a fall distance. It is standard practice to leave some cushion for a safety margin, typically 42-48”. Taken together, measured from the SRL snap hook starting point, we would need 124” to reach the ground or obstruction. Your circumstances may differ from this example in some way, but the underlying logic should be observed.



American National Standards Institute ( The Institute is a private, nonprofit membership organization that proposes, develops and publishes standards for all manner of commercial and industrial processes and operations. In our case, we are interested in ANSI Z359. This refers to a range of specific standards that relate to the manufacture and testing of fall protection equipment. Member manufacturers are able to certify that their products meet one or more of these standards.


Suspension trauma

When a fall has occurred, in theory you will be hanging from the SRL/d-ring attachment point on the full body harness. One consequence of this is referred to as ‘suspension trauma’, or orthostatic intolerance. What happens is that blood starts to accumulate in the legs, due to the leg straps reducing circulation. This is referred to as ‘venous pooling’, and is sometimes seen when people stand immobile for long periods of time. The victim will begin to feel faint or light headed. Loss of consciousness is not far behind, and in rare instances, death can occur. There is no strict timetable as to how fast this chain of events may occur, but it makes having a rescue plan for a fallen co-worker very important. We have available ‘suspension trauma straps’ as an accessory to be sold with full body harnesses. This strap assembly gives the worker a stirrup to stand in, relieving the pressure around the legs. Additional information is available at Search for ‘suspension trauma’.


3-way retrieval

Some self retracting lifelines have an additional ‘winch’ feature incorporated into their design. By means of a crank, the user is able to lower or raise a co-worker, all the while having the protection of a SRL. These are then said to be ‘3-way retrieval’ devices. Usually used on a tripod or davit system.


Impact indicator

All modern self retracting lifelines have built-in ‘impact indicators.’ Their purpose is to give a visual indication the unit has been involved in a fall arrest incident. At this time the manufacturer will want to have the unit inspected to make sure that all the internal components are undamaged and working properly. 3 common types are 1) a red ring that becomes exposed on the snap hook, 2) a fold of webbing that rips to reveal a printed warning or 3) a pop-out pin on the SRL housing itself. User training should include knowing what to look for on your particular device. Never use a lifeline with an exposed impact indicator. The lone exception here might be SRLs used in a training or demonstration program. In this case, a ‘Competent Person’ should be supervising these operations.



All self retracting lifelines are sold as having been inspected and certified at the factory to meet or exceed all relevant standards for operation and safety. After a time, the SRL may be used during a fall or other event that could potentially impair the proper functioning of the unit. The unit is returned to the factory or authorized service center for disassembly and inspection. Worn parts are replaced, and once put back together, the unit is ‘re-certified’ and available to be returned to service as if new. This is done on an ‘as needed’ basis, and may be the result of the required annual inspection by a ‘Competent Person’.



See 'Self Retracting Lifeline'



For our purposes, a lanyard refers to a connection device between an anchorage point and the d-ring on a full body harness. They are used for fall protection, and will usually incorporate a shock absorbing element intended to reduce the impact force being transmitted to the user in the event of a fall. The typical lanyard is 6 ft long, with a double-locking snap hook on either end. There are many variations, including the 100% tie-off lanyard (also referred to as double leg) where 1 hook attaches to the user, and the remaining 2 ‘legs’ are used to move from one anchor point to another without ever being fully disconnected.


Retractable lifeline

See 'Self Retracting Lifeline'


Self retracting lifeline

A ‘self retracting lifeline’ or SRL is a specific type of vertical lifeline used as part of a fall protection system. How it works may best be explained as being similar to the seat belt in a car. The lifeline, like the seat belt, pulls out and retracts easily. But give either a quick tug, and they lock. Release the tension and they move freely again. The self retracting lifeline also incorporates a braking system to spread the sudden impact force over a brief time and distance. This keeps the force transmitted to your body through the full body harness to a maximum of 900 lbs.


Clicker block

This is a nickname for the Ultra-Lock self retracting lifeline from DBI. As cable is pulled out of the unit, an audible clicking is heard by the user. Many customers find this sound to be an assurance that the unit is working. Engineers at most fall protection companies have worked hard to reduce or eliminate this sound in the search for smoother operation.


Fall restraint

The point of a ‘fall restraint’ system is to prevent or preclude you from falling. This may take the form of a ‘body belt’ or harness attached to a lanyard whose length is such that you can not get to the edge. One advantage to this is that your hands are free, and you are not preoccupied with concerns about falling. Also included in this are so-called ‘travel restriction’ devices like guard rails, including the portable variety used on many job sites.


Fall arrest

A ‘fall arrest’ system is designed to protect you in the event of a fall. This will usually consist of a full body harness, shock absorbing lanyard or lifeline and a secure anchor point. Once you have fallen, these components work together to manage the force of gravity and keep you from striking obstructions below, including the ground.


Body Belt

A ‘body belt’ is typically worn around the waist, and may have 1 or more d-rings for the attachment of lanyards. These belts may be used for fall restraint, where there is no danger of experiencing a fall from height. They should never be used for fall arrest, as they can cause severe injury (or worse) if used in this manner. The reason for this is that your body will become doubled over in an instant once the limit of your lanyard or lifeline is reached. The folding point will be opposite the d-ring that you are attached to. Is this the side, the back, or the front? Pick your poison, because even a very short fall will give you somewhere between 900 and 3600 pounds of force in what engineers refer to as ‘moment’ energy. If you prefer, ‘in an instant.’ You will have no power to resist, and will need more than a chiropractor afterwards.



A forged metal ring used on many full body harnesses as the attachment point for a lanyard or self retracting lifeline. The size and shape has been specifically engineered to be used with standard double-locking snap hooks.



Z359 is the ANSI standard referred to by fall protection manufacturers when engineering and certifying their products as suitable for use as fall protection devices. This standard has many sub-parts that govern specific parts of a fall protection system. The ‘Z359’ will be featured prominently on any piece of gear that meets the standard.


Vertical lifeline

This phrase can have two meanings in fall protection. Many times we are referring to a length of rope or cable hung from an overhead anchorage point. A so-called ‘rope grab’ allows the user to move up and down relative to the lifeline with the assurance that the device will stop and hold should there be a fall. Commonly used in roofing and window washing. A self retracting lifeline may also be referred to as a ‘vertical lifeline’, but since this may cause some confusion, we usually don’t.


Retractable lanyard

See 'Self Retracting Lifeline'


Safety Block

See 'Self Retracting Lifeline'