“A hook block is an assembly to which the hook of a hoist or crane is attached; it typically consists of a steel enclosure housing a number of sheaves or pulleys that carry the ropes or chains that facilitate the lifting of a load.
What is the hook on a crane called?
A lifting hook is a device for grabbing and lifting loads by means of a device such as a hoist or crane. A lifting hook is usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached.
How many types of crane hooks are there?
Single Crane Hooks and Double Crane Hooks
The most common crane hooks get Classified on the basis of their shape. Depending upon the shape there are two types of crane hooks that are single crane hooks and double crane hooks.
What is a crane load block?
A Load Block is the assembly of hook, swivel, bearing, sheaves, pins and frame and is suspended by hoisting ropes or load chains. It is used to lift and move objects up to a specific lifting capacity.
Why do cranes have two hooks?
It is quicker and easier to use. The larger hook is then used for heavy lifting. Both hooks can be used in tandem for complicated lifts, including flipping something upside down etc.
Who can operate a crane?
Operators of most cranes above 2,000 lb. capacity when used in construction will need to be either certified by an accredited crane operator testing organization, such as the National Commission for the Certification of Crane Operators (NCCCO), or qualified through an audited employer program [§ 1926.1427(a)].
What is two blocking a crane?
Two-blocking occurs when the operator extends the boom on a crane without letting out sufficient slack in the cable. As a result, the stabilizing weight, called the headache ball, will be popped off by the extending boom.
What is a slip hook?
Forged Clevis cargo slip hooks are designed with a wider throat than grab hooks which allows the chain to slip through the hook in order to hold it securely. Grade 70 Clevis Slip Hooks have a removable latch and clevis pin and are to be used with grade 70 or greater chain for load hauling and load securement.
What is a clevis hook?
The clevis is a U-shaped piece that has holes at the end of prongs to accept the clevis pin. … A clevis hook is a hook, with or without a snap lock, with a clevis and bolt or pin at the base. The clevis is used to fasten the hook to a bracket or chain.
Which material is used for crane hook?
Abstract In this paper the design of the hook is done by analytical method and design is done for the different materials like forged steel, wrought iron and high tensile steel. Crane hook is very significant component used for lifting the load with the help of chain or wire ropes.
Why does the crane need to rotate?
Why does the crane need to rotate? … It has an input force or effort from the diagonal cables right at the top of the crane pulling the jib up, and a load pulling the jib down.
What part of the crane is used to lift and lower the load?
Hoist – A mechanical unit that is used for lifting and lowering a load via a hook or lifting attachment.
What is creep speed?
CREEP SPEED: A very slow, constant, continuous, fixed rate of motion of the hoist, trolley, or bridge: usually established at 1% to 10% of the normal full load speed.
What is difference between lifting and rigging?
Rigging comes from rig, to set up or prepare. Rigging is the equipment such as wire rope, turnbuckles, clevis, jacks used with cranes and other lifting equipment in material handling and structure relocation. Rigging systems commonly include shackles, master links and slings, and lifting bags in underwater lifting.
What is the purpose of a fly jib on a crane?
A fly jib is a lifting device which assists a crane operator in picking and placing a load at a target area. A fly jib is particularly useful in that it allows the crane operator to place the load, such as construction materials, inside a multistory building.
What is the difference between hoisting and rigging?
is that rig is to fit out with a harness or other equipment while hoist is to raise; to lift; to elevate; especially, to raise or lift to a desired elevation, by means of tackle or pulley, as a sail, a flag, a heavy package or weight.