The following definitions will help you to interpret the language that could be found within the website and more specifically within your inspection report. This is not a complete list of all relevant definitions but does cover the most specific to climbing wall inspections.

ACCT – The Association for Challenge Course Technology; The largest and oldest trade association serving the challenge / ropes course community. ACCT writes and publishes standards for installation, inspection, operation, training and certification of facilitators and challenge course managers.The ACCT standards would be relevant to outdoor fixed climbing towers and some indoor climbing walls that are not utalized like a climbing gym.

ACA – The American Camping Association; Camp membership, training, bookstore and accreditation services.

AEE The Association for Experiential Education; The mission of AEE is to develop and promote experiential education worldwide.

ASTM International American Standards Testing Materials, A large standards setting organization. Amusement Code is maintained by ASTM 424 Sub Committee. This standard would be relevnt for mobile climbing walls and climbing structures that utalize auto belay systems.

ANSI American national Standards Institute – Accredits standards developer’s procedures for developing standards. ACCT and ASTM are ANSI accedited standards developers for the climbing wall industry.

ATC – Air Traffic Controller; A trade name for a specific belay device manufactured by Black Diamond (the industry model belay device). Aka Tuber.

Abnormal Operational Conditions – Environmental conditions that are unfavorable, harmful or detrimental to or for the operation of a piece of equipment, element, etc. Such as excessively high temperature, exposure to weather where manufacturer would require a covering, dust laden or moisture laden atmosphere or hazardous location such as under a high voltage wire, or a sharp edge that a climbing rope would run over.

Abrasion – The mechanical wearing of a surface resulting from frictional contact with other materials or objects.ex. abraded rope, shear reduction device or belay bar from excessive or abnormal wear.

Accept; Acceptable – A practice, design or method recognized by the industry or the authority having jurisdiction. Installations and practices that follow the ACCT, NAARSO or CWA standards for climbing walls would be deemed acceptable.

Accident - Any incident which does or could result or could have resulted in personal injury or damage to property.

Anchor; Anchorage – Place, fixing or fixture to which an anchor line or belay system is connected.

Anchor Line; Anchorage Line – Flexible line connected at least at one end to a reliable anchor to provide a means of support, restraint, or other safeguard for a person wearing a body support or harness. An Anchor line may be a lifeline or a working line. This is an industrial term for belay rope or belay system.

Approved – Accepted as satisfactory by a duly constituted administrative or regulatory body. Ex. Your climbing wall passes a state required inspection as regulated or required by law and provided by a NAARSO certified or ACCT Accredited inspector.

Arresting Force– The amount of force extended on a climber, worker or test weight when a fall protection system stops a fall. This is usually felt at the waist connection point on a typical climbing harness and should always be less than 900lbs in the worst case scenario like a fall while lead climbing.

Artificial Climbing Structure (ACS) – A structure designed and built for the sport of climbing. including ascending, descending, rappelling, and traversing over simulated rock surfaces. ACS may be temporary or permanent.

Ascender – A rope adjustment device which, when attached to a rope of appropriate diameter, will lock under load in one direction and slip freely in the opposite direction.

Authorized –Approved by a duty to constitutive administrative or regulatory body. Has been identified officially as the person or body who is trained, certified or approved to operate in their capacity or a specific capacity. Ex. Licensed Inspector, Licensed Contractor, Designer, Engineer, Builder, Inspector, Ride operator, etc. - ESI is authorized by most states to conduct climbing wall inspections as we are an ACCT Accredited Vendor and employ NAARSO Certified Inspectors.

Auto-belay – Auto-belays eliminate the need for a human belayer by automating the belay process through an engineered system. Two commercial examples include the TruBlue Magnetic Auto Belay and the fixed hydraulic autobelay systems (manufactured by Extreme Engineering, Vertical Reality and Spectrum Sports).

Back up Device – a rope adjustment device for a safety line which accompanies the user during changes of position or allows or allows adjustment of the length of the safety line, and which locks automatically to the rope, or only allows gradual movement along it, when a sudden load occurs.

Belay Device– A commercial or manufactured device used to assist in the control of the belay rope during the belay process. Ex. ATC, Tuber, Figure 8, Gri Gri, Eddy, Stitch Plate, etc.

Belaying – The act of taking up the slack in the rope (or lifeline) of a climber and assisting in the prevention of a fall by restricting the flow of the rope.

Belay Bar – A fixture attached to the top  of a climbing wall or tower designed to secure a climbing rope or multiple ropes for belaying. Belay bars are typically continuous or semi-continuous pipes or bars with structural supports or attachments. A single belay bar typically has multiple attachments to the ACS or other support structure.

Belay Cable– A belay cable is a horizontal lifeline typically constructed from 3/8” 7x19 galvanized aircraft cable for the support of human loads on a climbing walls. These are typically found on outdoor climbing towers as part of a challenge course or ropes course.



- Sewn loop that connects the leg loops and waist belt of a harness. Used to attach a Belay Device.

Brace – A structural element used to stiffen or support a portion of a structure or frame in between studs or steel supports.

Cable or wire rope - Most cable used in the construction of climbing wall belay systems is ⅜” 7 x 19 flexible, galvanized aircraft cable with a tensile strength of 14,400 pounds.Other cable sizes could also be used.

Cable Clamps-  Cable clamps  sometimes referred to as wire rope clips or U-Bolt clamps are typically  ⅜” dropped forged, galvanized or stainless steel for use on belay cables and guy wire ropes for outdoor climbing towers.  They are usually applied in pairs or groups of threes for securing cable to cable. 

Carabiners – A type of connector that can be made from aluminum, steel or stainless steel. Varieties of carabiners include non-locking, screw-gate locking, auto-locking and three-stage locking. Carabiners used on climbing walls, towers and gyms should have a minimum breaking strength of 22.2kn to meet current industry standards.

CEN - The European Committee for Standardization was founded in 1961 by the national standards bodies in the European Economic Community and EFTA countries.

Certified – The act or process resulting in documentation that determines and attests that certain criteria have been met. both the CWA and ACCT offer practitioner certification programs. ESI is accredited to offer these services.

Chest Harnesses- To be used in conjunction with a sit harness sometimes supplementing the need for a full-body harness.

CI – Cordage Institute – sets standards for rope manufacture and performance

Competent person – Designated person suitably trained or qualified by knowledge and practical experience to enable the required task or tasks to be carried out properly.

Component – See Fitting

Connector – Openable safety device, which enables a person to link himself directly or indirectly to an anchor (e.g. rapid link, carabiner, delta link, snap hook).

Controlled Stop – A timed and/or controlled deceleration of a moving device or person.   ex. Autobelays utalize a controlled stop system.

Dead Loads – The static load of the system or structure that does not change over time or during the course of normal use. Dead loads include the forcesexerted on the structure, panels, foundation or ground at point of attachment. (e.g. lumber, steel, rope used to construct structures)

Decay Resistant Materials – Naturally occurring or other artificial approved treatments commonly applied to wooden materials to resist environmental decay.Climbing towers built outdoors would require the use of decay resistant materials.

Deflect – To bend or deform under weight. Some deflection within a belay system is ok. Permanat deflection is an indicator that the structure was not engineered or designed properly or has somehow been overloaded.

Descenders - A device for controlled descent on a rope such as a figure eight descender. Some belay devices may be used as descenders (ATC, Tuber, etc).

Designer – the entity responsible for the theoretical or physical design of climbing wall or tower. (engineer, architect, or other qualified person) .

Designated Person – A person who is selected or assigned by the employee or employers representative as being competent to perform specific duties.

Direct Supervision - A situation whereby an instructor is in close enough proximity to physically intervene.

Document – Defines how work is to be done ( e.g. procedures, instructions, blank forms, etc.)

Dynamic Belay– A type of belay system where the belayer is typically below the climber assisting in the process of preventing a fall by taking up the slack in the belay rope.

Dynamic Rope– A type of rope used in belay systems that has approximately 4% to 8% stretch when loaded.

Energy Absorber – Component or components in a fall arrest system designed to absorb impact forces generated during a fall. Via OSHA laws all staff while climbing in a leading edge enviornment should have an energy absorber within thier belay or fall protection system (while guests or patrons on climbing walls are not required to use these).

End Fitting- Terminal hardware on the end of a rope, wire rope or sling.

Fall Factor– Maximum height a person could fall if held by the rope, divided by the length of the rope from the person to the anchor point.

Fall Zone – The volume or space in which a climber or overhead worker may fall into or swing into during normal operation of structure or completion of work task.

Fist Grip or Twin Base Clamp - A type of cable clamp that balances the pressure placed on the cable leaving the cable undamaged when properly installed.

Fitting - hardware on the end of a sling, cable or rope.

Fixed Point Load – A rigid bolt connection between a wooden beam and pole or tree.

Floating Point Load – A connection between a beam and a tree that allows a certain amount of movement for both the beam and the pole or tree to which it is connected.

Force – A reaction that develops in a member or structural element, e.g. axial loads, moments, shear and torsion.

General Supervision - A situation in which a climbing wall instructor can clearly see the participant but due to distance only intervene verbally.

Gri Gri – A type of auto-locking belay device. A trade name for an auto-locking belay device manufactured by Petzl.

Guy Cable – A supporting cable designed to support or transfer loads from one structure to another structure or component. Typically a cable installed at a 45 degree angle to the intended loads application and terminated above the belay cable and to a ground anchor. These are typically only found on outdoor and portable climbing towers.

Guy Guards - Bright plastic tubes put around guy cable to increase visibility.

Hauling Lines- Lines used to lift materials and tools to desired elevated work stations.

Incident – An incident is any situation in which a participant, as a result of contact with an object or another person is unable to continue an activity at the same level as was possible before the situation occurred.

Inspector – an individual who is qualified by experience, education,  training  or certification to inspect climbing walls. ex. ACCT Accredited Vendors, and NAARSO Certified Inspectors.

Knee Brace – A support post that angles back and below from the beam it supports to the vertical column or tree.

Knot - A fastening made by tying a rope, webbing or two ropes or webbing together.

Lag Bolt – A large lag screw with a square or hex head

Lanyard – A safety rope used when securing oneself above the ground on an elevated work surface or on a pole or tree or climbing structure.

Lap Splice – The connection where are joined in line with wire rope clips or swage sleeves (ferules)

Live Loads – Loads acting on the structure that change over time or during the course of normal use.  Live loads include all of the forces that are variable during the course of normal use, included but not limited to the forces imparted by the stationary, moving or falling participant or person.

Loads – A force or system of forces carried by the structure or any of its elements.

Lobster Claw– A type of lanyard used in static belay ropes courses such as a participant lanyard or instructor lanyard.

Low Stretch Rope – textile rope with a lower elongation and, therefore, less energy absorbing characteristics than dynamic rope.

Machine Bolt- Machine bolts have square heads and are typically ⅝” in diameter.  They are hot dip galvanized.  Their tensile strength is 12,400 pounds.

Maillon Rapide- A trade name for a rapid link with tensile strength rating printed on the side. Rapid Links utalized for life support systems and belay anchors should be Mallion Rapide brand.

Manufacturer– the entity responsible for the physical production of an item or course. The climbing wall manufacturer will also have a written set of policies for operation, inspection and maintenance that should be followed.

Near Miss - Any incident in which there is no actual injury, but if conditions were varied even slightly an accident would have occurs. NOTE e.g. a climbing hold falling within the vicinity of a group, but missing everyone climbing or on the ground.

Normal Use – use of structure or equipment as intended by the manufacturer within strength and operational requirements.

Nut Eye Bolt (NEB) - Nut eyebolts are typically ⅝” drop forged galvanized steel eyebolts. Their tensile strength is 17,500 pounds.

OSHA /Occupational and Safety and Health Administration – Oversees and regulates worker safety.

Oval Eye Bolt (OEB) - Oval eyebolts are typically ⅝” drop forged, galvanized steel bolts with 12,400 rated tensile strength.

Pole Installation Depth - Normal pole installation minimum depth is ten percent of the pole’s length plus two feet or four feet minimum.

Proof Load – the specific load applied in performance of the proof tests.

Proof Test – A nondestructive load or tension test made to a specific multiple of the rated load of the system or component.  Performed by the manufacturer or equivalent qualified industry or technician to verify workmanship and usability for intended applications.

Proper Training– Training from a reputable school, college, university, trade organization or company that has a formalized apprentice program.

Prusik Knot– A friction knot made by creating a series of loops around a static line that tightens when weight is applied to the knot.

Pulleys - A pulley typically consist of a grooved wheel on a shaft with side plates for carrying a rope. Pulleys used on climbing structures should be made of study corrosion resistant materials with a minimum breaking strength of 5,000 pounds.

PPE - Personal Protective Equipment (helmets, eye-ware, harness, etc.)

Qualified Person – A person who, by possession of a recognized degree or certificate of professional standing in an applicable field, or who by extensive knowledge, training and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work.

Reasonable Person – a rational, reasonable responsible intelligent person, appropriately informed, fair, and aware of the law; intended to mean the average person.

Redundancy – A system or subsystem or device designed to back up and serve as a fail-safe if the primary component failed.

Record – A record provides evidence of work done. (E.g. Purchase orders, signed contracts, completed and signed forms, etc.)

Rapid Link - A very strong oval shaped steel connector also referred to as a Quick Links.

Rated Capacity – refer to rated load.

Risk – The probability of loss occurring, expressed as a percentage or as a fraction. Also the non sequentialized chance that a person or system is exposed to harm, injury or loss.

Safe Work Load (SWL) - Generally 1/5 or 20% of the tensile strength of the material.

Shear – The deformation force in a structural element, usually a beam or bolted connection, in which parallel planes tend to slide relative to each other.

Sheave – A grooved wheel in a pulley or block for cable or rope to run over or through.

Shock Load – The load resulting from a constant applied force or load.

Splice - To join lengths of rope together by interweaving the strands of the rope; to join together two pieces of cable by using multiple swage sleeves or cable clamps.

Spotting – Spotting is a type of fall protection used on traverse climbing walls where a group of individuals act as support to the participant in preventing a fall. A particular stance and hand positions is used.

Static Rope– A type of climbing rope that has minimal stretch or low elongation. Static rope is not to be used on challenge course elements that require jumping or regularly receive significant shock loading.

Supervisor – A person charged with the responsibility of directing the work of others and the safe operation of all structures and equipment.

Swage (Swage sleeve) – An copper or aluminum oval shaped tube compressed onto wire rope to make a connection typically rated at 100% cable strength. Copper or zinc plated copper must be used on all critical terminations and lifelines in pairs.

Tension – The state, for example in a column or an element of a truss, whereby a member is being lengthened by a force (stretched). Tension is an axial load that is the opposite of compression.

Thimble - A tear drop shaped piece of curved metal that can be applied into the eye of rope or cable to protect wear and increase the life of the rope or cable.

Thimble Eye Bolt (TEB) – Thimble eyebolts are typically ⅝” in diameter and are hot dipped and galvanized with the thimble configuration cast into the eye portion of the bolt.  The tensile strength is 12,4000 pounds.  Angle thimble eyebolts have the same characteristics of the thimble except that the eye of the bole is offset 45º.

Traverse - To climb horizontally rather than vertically.

Tying in - To attach yourself to your harness with a rope by a prescribed knot normally a figure of 8 or bowline.

UIAA – Union of International Alpine Associations, sets European standard for climbing equipment.

Ultimate Load – The average load of force at which the product fails or no longer supports the load.

Universal – Climbing wall structures or events that can be utilized by both able body and individuals with disabilities.

Utility Poles- Poles used on a outdoor climbing tower must be decay resistant.  CCA (Chromium Copper Arsenate) is the preferred chemical treatment.  Utility poles are rated by circumference size at the top and butt and are divided into classes.  Class 2 is generally preferred pole for most typical climbing tower designs.

Vertical Life Lines - Vertical cables designed to facilitate easy and safe accessing by instructors. Attachment to the cable is by means of an industrial ascending device (cable grab or rope grab). 

Wind Load - A force or lateral pressure in pounds per square foot that is applied to a member due to wind blowing from any direction.

Wind Shear – the force created on a structure by wind.

Working Line - Anchor line used primarily for work positioning and restraint including ascending and descending.

Working Load Limit – The maximum mass or force at which the product is authorized to support a particular service.