| alloy steel chain sling |
A sling made from steel and consisting of a master hook, chain links, and sling hooks. Alloy steel chain slings are the strongest type of sling. |
| American National Standards Institute |
A private organization that sets voluntary standards for commercial products and services. Riggers must follow all ANSI standards for safety and inspection. |
| bend |
A type of knot that is used to join two pieces of rope. |
| block and tackle |
A moveable pulley that is used to raise and lower loads. |
| boom |
A timber or metal section of a strut that has its lower end hinged or pivoted at a fixed location on the mast while its upper end is supported by chains, ropes, or rods. A boom is necessary for lifting with hoists and ropes. |
| breaking strength |
The point at which a rope will break from stress. The breaking strength is a measure of a rope's ability to carry a load beyond its working load limit. |
| breech |
The side opening on a moveable pulley that provides access to the sheave. |
| bridge |
The part of the crane that carries the trolley. Bridges consist of girders, trucks, end ties, footwalks, and the drive mechanism that carries the trolley. |
| center of gravity |
The point on a body at which the weight is distributed equally in every direction. |
| chain |
A series of linked metal rings that are fitted together. Chains can lift heavy loads and are resistant to abrasion and corrosion. |
| clamp |
An end fitting used to secure hardware to the end of a rope. |
| compound block and tackle |
A pulley system that consists of two or more ropes with two or more blocks. A compound system is made up of two or more simple systems. |
| cordage |
Any type of fiber rope. Cordage can be natural or synthetic. |
| cotton |
A soft material that comes from the cotton plant. Cotton has the lowest strength of all fiber rope, but it can withstand a great deal of bending. |
| crane |
A machine for lifting and moving extremely heavy loads. A crane provides both vertical and horizontal movement of heavy and oversized loads. |
| Dacron |
A type of polyester. Rope made from Dacron is heavier than nylon rope, but not as strong. |
| derrick |
A lifting device with a mast held at the head with guys or braces. Derricks come with or without a boom for use with a hoisting mechanism and operating ropes. |
| drum |
A large, cylindrical device used to wind and unwind ropes and chains. |
| eye hook |
A commonly used type of hook with a forged opening at one end. Eye hooks can come with or without a latch. |
| eye splice |
A type of splice that is used to make a permanent loop at the end of a rope. |
| eyebolt |
A threaded bolt with a forged hole or loop at one end. |
| fail |
In mechanics, failure refers to the deformation and eventual rupture of an object under stress. A failed component no longer function properly and often poses a safety hazard. |
| fiber |
A thin, elongated piece of material that, when combined with other pieces of fiber, can be twisted to form a yarn. |
| fiber rope |
Rope made from plants such as hemp and cotton. |
| fulcrum |
A pivot point of a lever, or the point around which an object turns. |
| gantry crane |
A crane with a bridge supported on two or more legs running parallel on fixed rails. |
| grade designation |
A standardized measure of the chain's strength. |
| hemp |
A coarse material that comes from hemp plants. Hemp was one of the first materials used to make rope for rigging. |
| hitch |
A type of knot that forms a noose around an object such as a pipe or a post in order to secure it. Hitches are meant to be temporary and therefore can be undone easily. |
| hoist |
A lifting device that exerts vertical forces for lifting and lowering, usually from a position that is directly above the load. |
| hook |
A curved piece of hardware that is used to suspend or hold something. |
| hydraulic jack |
A type of jack that has a pump plunger that forces a fluid through a cylinder. |
| jack |
A tool used for lifting large or heavy objects. Jacks are used for items that cannot, or should not, be lifted with a crane or hoist. |
| J-hook |
A hook in the shape of the letter "J." J-hooks are designed for use with chains, hoists, and slings. |
| jib hoist |
A hoist with a boom for added length for lifting specified loads. The jib may be in line with the boom or offset at various angles. |
| knot |
A fastening that is formed by tying a rope to another object or to itself. A good knot should be easy to tie and untie, and it should hold without slipping. |
| lashing |
A rope, cord, or chain that is used to fasten two objects together securely. |
| lay |
The direction in which the strands of a rope are twisted. |
| lever |
A type of simple machine consisting of a rigid bar that pivots on a fulcrum. Levers are used to transmit motion and alter mechanical advantage. |
| lift capacity |
The maximum lifting force of the jack. |
| lift stroke |
The difference between the fully retracted and fully extended positions of the jack. |
| load |
The opposition to applied force, such as a weight to be carried or moved. |
| Manila |
A material that comes from the leaves of the abaca, a type of banana tree that grows in the Philippines. |
| maximum height |
The distance from the base of the jack to the lifting element when it is fully extended. |
| metal mesh sling |
A sling with fabric made of spiral, welded, or brazed wire or chain and cross rods. |
| millwright |
A person who specializes in rigging. Millwrights oversee rigging, moving, installing, and leveling heavy equipment. |
| minimum height |
The distance from the base of the jack to the lifting element when it is fully retracted. |
| moveable pulley |
A circular lever that rotates around the fulcrum. A block and tackle is an example of a moveable pulley. |
| natural fiber rope sling |
A sling made of conventional three-strand-construction fiber rope. Manila is a common natural fiber material used in slings. |
| nylon |
An artificial material made from polymers. Nylon rope is stronger and more resilient than natural fiber rope. |
| Occupational Safety and Health Administration |
A government agency dedicated to reducing injuries, illnesses, and deaths in the workplace. Riggers must follow all OSHA standards for inspection and care of equipment. |
| overhand knot |
A simple type of fastening in which a rope is twisted into a loop, and one end of the rope is inserted through the loop. |
| overhead crane |
A crane with a movable bridge carrying a movable or fixed hoisting mechanism and traveling on an overhead fixed runway structure. |
| overhead hoist |
A hoisting mechanism used with an overhead lifting device, such as a crane. |
| pin |
A cylindrical metal component used to close a shackle for rigging applications. |
| pulley |
A rotating circular device that is used to raise or lower a load or transmit motion. A block and tackle is a type of pulley. |
| ratchet jack |
A type of jack with a lever that raises the jack up or down with each downstroke. |
| rigging |
The process of lifting and moving heavy loads with ropes, chains, and mechanical devices. |
| rigging equipment |
The hardware, tools, and machines used for moving loads. |
| rope |
A length of fibers or wires that are twisted together for strength. Ropes are used for pulling, connecting, and securing. |
| screw jack |
A type of jack that consists of a threaded cylinder that is moved up or down when the handle of the jack is turned. |
| shackle |
A U-shaped piece of metal that is closed at the end with a pin or bolt. |
| sheave |
The freely moving wheel that is part of a moveable pulley. The sheave usually contains a groove to hold a rope or chain. |
| shell |
The outer covering on a moveable pulley. |
| shoulder eyebolt |
An eyebolt used for increased strength when side forces impact the load during lifting. |
| simple block and tackle |
A pulley system that consists of a single line with one or more blocks. |
| sisal |
A material that comes from plants. Sisal is not as strong or durable as Manila. |
| sling |
A loop of material, which connects the load to the lifting device. Slings can be made of chain, wire, metal mesh, natural, and synthetic materials. |
| splicing |
A method of joining two ends of rope by unlaying the strands, placing the rope ends together, and interweaving the strands. |
| standard eyebolt |
An eyebolt without a shoulder that is used only for vertical lifting. |
| strand |
A thread made by twisting fibers together. |
| synthetic fiber rope sling |
A sling made of conventional three strand construction synthetic materials such as nylon, polyester, and polypropylene. |
| synthetic fibers |
Fibers made from nylon, Dacron, or other artificially made materials. |
| synthetic web sling |
A sling made of conventional three strand construction synthetic materials such as nylon, polyester, and polypropylene. |
| thimble |
A pear-shaped piece of hardware used to reinforce the loop in an eye splice. Thimbles protect the rope from damage. |
| thread |
A raised, helical rib or ridge around the interior or exterior of a cylindrically shaped object. Threads are found on screws, nuts, and bolts and are used to fit parts or provide motion. |
| timber hitch |
A type of fastening in which a rope forms a noose around an object, and the end of the rope is looped several times through the noose to secure it. |
| trolley |
The unit which travels on the bridge rails of a crane and carries the hoisting mechanism. |
| vegetable fibers |
Plant fibers such as Manila and sisal. |
| wedge socket |
A type of fitting that can be installed and removed quickly and easily. |
| wire |
A thin, elongated piece of metal. Strands of wire are twisted together to make wire rope. |
| wire rope |
Rope made from strands of steel or iron. Wire rope is used for jobs that require the rope to be extremely strong and resistant to abrasion. |
| wire rope sling |
A sling composed of wire rope that is either, braided, bridled, cable laid, or strand laid. |
| working load limit |
The maximum load that the rope is designed to carry. |