One common issue that crane operators run into is crane skewing. Overhead crane skewing is when the bridge is not perfectly perpendicular to the runway. It can be caused by a variety of conditions and must be fixed before operations begin.
What is skewing in crane operations?
Skewing Forces: Lateral forces on the bridge truck wheels caused by the bridge girders not running perpendicular to the runways.
What is a crane girder?
· A single girder crane has only one bridge beam, and the hoist trolley operates or travels on the lower flange of the bridge girder. · A double girder crane will have two bridge beams, and the hoist trolley travels on rails, usually attached to the tops of the crane girder.
What is headroom in Crane?
Headroom is the distance measured from the saddle of the load hook, when in it’s highest lift position; typically to the following locations: Bottom of bridge girder.
What are the components of a crane?
Some of these parts and their functions include:
- The Driving Components. In any mobile crane, one of the common components will be the driving system used to make it mobile. …
- The Operator’s Cabin. The operator’s cabin houses all of the crane’s controls. …
- The Boom. …
- Hoist and Hook. …
- Hydraulic Pump. …
- Outriggers and Counterweights.
6 февр. 2020 г.
What is the problem of a crane?
If overhead crane is out of alignment and skewing then it can lead to significant stress and damage to whole crane system. While construction of the crane, forces applied can also cause stress in the crane and hence this type of stress can result in accidents, crane failure, productivity loss and replacement of loss.
What are the 5 principal parts of Category 1 and Category 4 cranes?
Crane Components The principal parts of most Category 1 and Category 4 cranes are: the boom, machinery house, roller path or rotate bearing, supporting structure, and travel system.
What is the end of a crane called?
JIB CRANE – A crane design whereby the bridge girder (commonly called the boom) is fixed at one end, allowing the opposite end to cantilever. The fixed end generally is hinged to allow rotation. LIFT – Maximum safe vertical distance through which the hook, magnet, or bucket can move.
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.
Which motor is used in overhead crane?
While series DC motors consume more power than PMDC motors to produce their electromagnetic field, they’re powerful, efficient at high speeds and produce the most torque; hence, they are used for heavy duty winches. Shunt DC motors are used in constant speed applications, 18 such as reel drives.
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.
How does an overhead crane work?
What is an Overhead Crane? Overhead cranes cover a rectangular area, moving a load side to side and backward and forward. The lifting device, called a hoist is mounted on a trolley for horizontal movement across a bridge beam connected to one or more horizontal girders which are supported at either end by end trucks.
What are the three functions of a crane?
The main purpose of a crane is to lift extremely heavy amounts of weight. A typical crane is equipped with a hoist rope, wire ropes or chains and sheaves.
Modern day cranes are used for:
- Construction Materials.
- Railroad Tracks.
- Shipping Materials/Equipment.
- Scrap Metal.
- Mobile Homes.
5 нояб. 2015 г.
What does OSHA consider a crane?
A crane is a machine for lifting and lowering a load and moving it horizontally, with the hoisting mechanism an integral part of the machine. … Floor-operated crane means a crane which is pendant or nonconductive rope controlled by an operator on the floor or an independent platform.
What is the boom of a crane?
The Boom: The boom is probably the crane’s most outstanding and identifiable feature – this is the long, telescopic or fixed arm that is used to move objects. The Counterweights: The crane’s counterweights are near the cab’s exterior – they prevent the crane from becoming unbalanced when lifting heavy loads.