>  Glossary


Not sure how to calculate fall distance or what the difference is between an anchorage and an anchorage connector? Refer to our glossary for help defining the terminology we use throughout this site. Still confused? Contact our customer service experts and we’ll help you sort things out.​



ABC’s of Personal Fall Protection

The basic elements of any fall protection system are A for anchorage, B for body support and C for connectors.


Active Fall Protection System

A means of providing fall protection that requires workers to actively wear and use fall protection equipment, and which requires training.



A secure point of attachment for lifelines or deceleration devices, e.g. lanyards & self retracting lifelines.


Anchorage Connector

Provides a connection point onto an anchorage or building structure in order to attach the rest of the fall arrest system.


Arresting Force

The force imposed upon the worker and the anchorage point the moment the fall arrest system stops the fall. It is measured in kilo newtons (kN), a maximum of 6kN is allowable.




​Back D-ring

Also known as the dorsal attachment or dorsal D-ring. Attachment point that is located on the back of the full-body harness, positioned between the shoulder blades.


Body Support

Comes in the form of a full body harness that provides a connection point on the worker for the personal fall arrest system. Depending on the application, they can be used as part of a system to protect the worker from falling and to limit the extent of potential injury in case of a fall.




Certified Repair Facility (Factory Authorized)

A centre that has been approved by the manufacturer to repair and certify equipment.


Climb Assist

A vertical fall protection system that assists the user in the ascent or descent of a fixed ladder to reduce fatigue.



A device used to join together components of a personal fall arrest system or parts of a component within the system.


Confined space

An enclosed or partially enclosed space that is at atmospheric pressure during occupancy and is not intended or designed primarily as a place of work, and (1) is liable at any time to - a) have an atmosphere which contains potentially harmful levels of contaminants; b) have an oxygen deficiency or excess; or c) cause engulfment; and (2) could have restricted means for entry and exit.


Counterweight System

A system that uses weights to provide a sturdy support structure to offset the weight of a worker.



Equipment is deemed compatible when they have been designed to work together in such a way that their size and shape do not cause them to separate inadvertently during use.


Competent Person

AS/NZS 1891.4 defines a Competent Person as: A person who has, through a combination of training, education and experience, acquired knowledge and skills enabling that person to correctly perform a specified task.


Competent Person Classifications

Height Safety Operator - A person who is able to perform harness based work at heights under the direct supervision of a height safety   ​supervisor


Height Safety Equipment Inspector - A person who is competent in the skills needed to detect faults in height safety equipment and to determine remedial action.


Height Safety Manager - A person who is competent in the selection, design, manufacture or installation of height safety systems or equipment, or the development of control measures or work practices.



D-Ring/Attachment Point

An attachment point on the rear or front of the harness which allows for the connection of other components of a fall protection/ positioning system such as a lifeline or deceleration device.


Davit Arm or Davit Post

Davits are an alternative to the basic tripod. They have a variety of base configurations to fit a wide variety of openings and holes.


Debris Net

A netting system that is designed to contain debris. These systems are usually not rated for fall arrest.


Deceleration Device

Any device which utilises an energy absorption component to minimise the impact of the force created during a fall on the body, such as a lanyard or self retracting lifeline.


Deceleration Distance

The additional vertical distance a falling worker 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 workers 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 worker comes to a full stop.


Demonstration Trailers

Vehicles typically used for on-site fall protection training and demonstrations to conduct drop tests and showcase the proper use of fall protection equipment


Descent System

A system used to help safely lower a worker to a lower level of a structure or to the ground in a controlled manner.


Dorsal D-ring

Also known as the back D-ring. Attachment point that is located on the back of the full-body harness, positioned between the shoulder blades.


Dorsal Extension

A device that connects to the rear D-ring of your harness that enables easier connections to lanyards and other devices by extending the reach from the rear D-ring.


Double or Triple Action Device

A self-closing hook or karabiner with a keeper latch which will automatically close and remain closed until manually operated. These units have a minimum of two (double) or three (triple) distinct and deliberate consecutive actions to manually open them.



Fall Arrest Systems

Systems that protect the worker after a fall from hitting the ground and/or obstructions below the work platform. Passive systems require little or no personal involvement from the worker. Active systems require the worker to actively use the system in order for it to be effective. It is not always practical, cost effective or possible to employ passive systems. In these cases, a Personal Fall Arrest System is required.


Fall Clearance

The vertical distance needed to safely arrest a fall. When using a self-retracting lifeline, a minimum of 1.4m of clearance from the working level to the lower level is recommended. When using a lanyard, the required distance from the anchorage to the nearest obstruction equals lanyard length plus, deceleration distance, height of the worker and a recommended safety factor of 1m.


Fall Clearance Calculation

To determine the required fall clearance add the appropriate factors together, this will give you the safe required distance (RD) below the working surface for work which is to be carried out where there is any risk of falling. Calculation: free fall distance energy absorber deceleration distance clearance to obstruction during fall arrest


Fall Hazard

Any location where a worker is exposed to a potential fall.


Fall Indicator/Impact indicator

A visual indicator that shows the fall arrest system or device has been used to arrest a fall.


Fall Prevention

Refers to the systems and techniques that eliminate the possibility of a fall to a lower level. The most desirable method of fall prevention is to engineer out or modify the work plan to eliminate the hazard.


Fall Protection

Refers to the overall industry and process of protecting workers at height.


Fall Protection Equipment

Equipment that is used by a worker to prevent or arrest a fall.


Fall Restraint System

A system that prevents a worker from reaching a fall hazard.


First-Man-Up System

A system used to install and remove a fall protection device to an overhead location using a telescoping pole and adaptor tool.



Measured in technical terms in Newtons (N). The weight of something in Newtons (N) is calculated by multiplying its mass in Kilograms (kg) by the value of Gravity, which is 9.81 (m/s2). A Kilogram (kg) is a unit of mass (i.e. the weight of a static object).

Force = Mass x Acceleration.

For rough calculation purposes: 1000N = 1kN, 1kN = 100kg, 10kN = 1000kg.



The act of falling before a personal fall arrest system begins to apply force to arrest the fall.


Free Fall Distance 

The vertical displacement of the fall arrest attachment point on the worker 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, and lifeline/lanyard elongation, but includes any deceleration device slide distance or self-retracting lifeline/lanyard extension before they operate and fall arrest forces occur.


Frontal D-ring

A connector located on the front of a full-body harness in the sternum area.



Guardrail System

A passive form of fall prevention. Usually a barrier consisting of vertical and horizontal rails to prevent workers from reaching a fall hazard.





Any metal component such as a D-ring, snap hook or karabiner used to attach components of a fall protection system.


Harness (Full Body Harness)

A webbing assembly that is worn by the user to distribute the arresting forces throughout the body in the event of a fall. The harness is equipped with attachment points to connect it to other components of a personal fall arrest system.


Hierarchy of Control

The hierarchy of control is a sequence of options which allow you to control a hazard from the highest level of control to the least preferred option. These measures, in order, are: identification, elimination, substitution and isolation. If these are not practical, fall protection equipment must be used.


Horizontal Lifeline (HLL)/Rail System

A flexible line supported by two or more anchorages, to which workers can connect a lanyard or SRL and travel safely along the line length. HLL’s can be designed for total restraint or fall arrest.


Horizontal Life Line – Permanent

A permanently installed horizontal lifeline that is built into the structure for use as the anchorage not only during construction, but also for maintenance and repairs later on.


Horizontal Life Line – Temporary

A pre-engineered horizontal lifeline system that is easy to install/remove and can be used on more than one jobsite without damaging the surface that it is attached to.



Inertia Reel

An inertia-activated reel that retracts and releases. In the event of a fall the reel locks.


Intermediate (HLL Reference)

Lifeline connection points that support the HLL at mid points and divide the overall length of the HLL into smaller spans.





A connector with a self-closing gate that can be manually locked or that automatically locks, and is used to attach to a fall protection component. Can be double action or triple action.



Lanyard Assembly/Shock-Absorbing Lanyard

A line of rope, webbing or cable incorporating a shock absorber and connectors at each end to connect the harness to the anchor device.


Latch Protection Device

A device that attaches to the eye of a snap hook that reduces the risks that can become present in various work methods/techniques that causes the webbing or shock absorber to wrap around the back of the locking gate of the hook and unintentionally ‘trip’ the gate.


Leading Edge

The edge of a floor, roof, or formwork for a floor or other walking/working surface (such as the deck) which changes location as additional floor, roof, decking, or formwork sections are placed, formed, or constructed. A leading edge is considered to be an "unprotected side and edge" during periods when it is not actively and continuously under construction.


Lifelines (VLLs, HLLs or SRLs/SRDs)

A component consisting of a flexible line for connection to an anchorage at one end to hang vertically (vertical lifeline), or for connection to anchorages at both ends to stretch horizontally (horizontal lifeline), and which serves as a means for connecting other components of a personal fall arrest system to the anchorage.


Load Arrestor

A back-up safety device to completely stop a dropping load (material loads only, not personnel) if it breaks free from the main support line. It is typically used in conjunction with lifting equipment such as cranes and hoists.


Lower Levels

Those areas or surfaces to which a worker can fall. Such areas or surfaces include, but are not limited to, ground levels, floors, platforms, ramps, runways, excavations, pits, tanks, material, water, equipment, structures, or portions thereof.



Manual Descent Control Device

A friction device that, once engaged, requires the user to control lowering speed.



Netting System

Passive systems, usually designed to contain debris or for fall arrest.




Pass Through Buckle

Is composed of two mating flat metal frames. The female frame is an open rectangle that is permanently attached to a loop at the end of a strap. The male frame is attached to the joining strap by passing the webbing through the two slots in the frame. To engage the buckle, turn the male buckle at an angle so that it will pass through the female frame. After it has passed through, turn it back so that the male frame lies directly on top of the female frame.


Permit-Required Confined Space

A space that has one or more of the following characteristics: (1) contains or has a potential to contain a hazardous atmosphere; (2) contains a material that has the potential for engulfing an entrant; (3) has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or (4) contains any other recognized serious safety or health hazard (such as a fall hazard).


Personal Fall Arrest Systems (PFAS)

A combination of components that when used together will arrest a person in a fall from a working level. A PFAS typically consist of: an anchorage, full body harness, connectors and a deceleration device such as a lanyard or SRL.


Personnel Net

A netting system that is designed to withstand fall arrest forces.


Pole Strap

A work positioning strap designed to be placed around a pole/structure and attached at two points, one on each side of a line worker’s fall arrest harness while the wearer is working on the pole.


Positioning Device

A full body harness system rigged to allow a worker to be supported on an elevated vertical surface, such as a wall, and work with both hands free while leaning.




Quick-Connect Buckle

A buckle that allows for one-handed operation for fast and easy donning of a full-body harness.




The ability to retrieve or rescue an individual from confined spaces or heights. Rescue must always be a component of any fall protection program.


Rescue Positioning Device (RPD)

A rescue or positioning system that allows the worker to simply raise or lower himself or someone else to a work level.


Rescue System

Equipment and components used to help a fallen worker return to the ground or location from which he or she fell, or that retrieves or evacuates an worker from dangerous situations or confined spaces.


Restraint Technique

Control on a person’s movement by connection to an anchorage to physically prevent the person from reaching a position at which there is a risk of a free or limited free fall.


Risk Assessment

The evaluation of hazards within the worksite which have the potential to cause frequent serious injury or illness to occur.



Radio-frequency identification technology is incorporated into a product through RFID Tags for identification and tracking purposes using radios waves.


Rope Grab

A deceleration device which travels on a lifeline and automatically, by friction, engages the lifeline and locks so as to arrest the fall of a worker. A rope grab usually employs the principle of inertial locking, cam/level locking, or both.




Shock Absorber/Energy Absorber

A webbing device that is designed to tear or extend, to reduce the forces on the worker in the event of a fall to less than 6kN.


Snap Hook

A connector with a hook shaped body that has an opening for attachment to a fall protection component and a self closing gate to retain the component within the opening. Hooks must be double-acting to be compliant.



The distance between intermediates or anchor points for a horizontal lifeline system.


Sub-Pelvic Strap

A strap incorporated into a full body harness which passes under the buttocks connecting the two leg loops. It is designed to distribute the forces from the inside of the legs to the outside to lessen the effect of injury following a fall.


Suspension Intolerance

(Also known as Orthostatic Intolerance, Suspension Trauma). A term used to describe the potential after-effects of immobile suspension within a full body safety harness following a fall from height. It presents with the development of a range of symptoms which may result in unconsciousness or death, and is thought to occur as a result of low blood pressure secondary to blood pooling in the legs, pelvis and abdomen of victims who are suspended and motionless.


Suspension Trauma Straps

A device that can be attached to or is integral on a full-body harness that is deployed following fall arrest and used to minimize the impact of suspension trauma.


Swing Fall

A pendulum-like motion resulting from a fall that occurs in a position located horizontally away from the anchorage.



Tie Back Lanyard

Acts as both the connecting means and an anchorage connector and comes in two styles. One incorporates an adjustable D-ring on the lanyard for attaching the snap hook and the other is designed for the hook to go around the webbing itself, which requires a specialty hook with a gate strength capacity of 5,000 pounds (22kN).


Tie-Off Adapter

Alternative anchorage connectors for a fall arrest system made of different materials, including cable, web and chain.



Lightweight, portable devices usually used for manhole entry and retrieval applications.



An anchorage connector that rolls along the I-beam to provide horizontal mobility to the worker.


Twin-Leg Lanyard 

Also known as double-leg lanyard. Two lanyards that are connected at one end. Used to provide 100 precent tie-off to keep the worker protected in the event of a fall at all times as he or she moves from one location to another.


Total Restraint

Control on a person’s movement by means of connection to an anchorage using nonadjustable equipment in such a way that it will physically prevent the person from reaching any position at which there is risk of a fall, either over an edge, through a surface or due to a failed moveable platform.


Type 1 Fall Arrest Device

Includes rope & rail grabs - A fall arrest device that travels along an anchorage line and, when loaded, locks to the line. The user is connected to the activating lever, which locks the device in the event of a fall. A typical use of a Type 1 device is as a ladder fallarrest system, using a rigid rail or flexible line attached to the ladder.


Type 2 & 3 Fall Arrest Device - Self Retracting Lifeline (SRL)

A deceleration device containing a drumwound line which may be extracted and retracted under slight tension when the user moves vertically away from and towards the device. In the event of a fall, the device will quickly lock the drum and prevent the lifeline from paying out, thus arresting the user’s fall and limiting the force to 6kN. When incorporating a retrieval winch, it becomes a type 3 fall arrest device.



Unprotected Sides and Edges 

Any side or edge (except at entrances to points of access) of a walking/working surface, e.g., floor, roof, ramp, or runway where there is no wall or guardrail system a minimum of 0.9 metres high above the walkway/working surface​.




Vertical Lifeline System

A flexible line rigged from one or more anchors to which a worker can secure the components of their fall protection system in a vertical orientation. These systems provide freedom of movement whilst maintaining user protection from a fall from height.




Walking/Working Surface 

Any surface, whether horizontal or vertical on which a worker walks or works, including, but not limited to, floors, roofs, ramps, bridges, runways, formwork and concrete reinforcing steel but not including ladders, vehicles, or trailers, on which workers must be located in order to perform their job duties.



Woven fabric used on fall protection equipment components such as full-body harnesses and lanyards.


Wedge Grip

Easily adjusted termination for wire rope cable, requires no tools to install and is 22Kn rated.



A device that lifts and lowers loads and contains a mechanism that controls pay-out and take-up of the line. Provides a mechanical lifting advantage.


Work Area

A portion of a walking/working surface where job duties are being performed.


Work Positioning

Use of fall protection components in a way that allows a worker to be supported in a harness under tension, so that a fall is prevented, e.g. the use of a pole strap or lanyard.




3M Fall Protection combines the products and expertise of DBI-SALA® and Protecta® with the technology and innovation of 3M to elevate safety to new heights and keep workers comfortable, confident and safe every time they climb. See our products and services at 3M.com/FallProtection.