A crane is a machine used for lifting and lowering a load and moving it horizontally, with the hoisting mechanism an integral part of the machine. Overhead cranes are used in many industries to move heavy and oversized objects that other material handling methods cannot. Overhead cranes have a railed support structure, known as a bridge, and a wheeled trolley that travels across the bridge horizontally. The other primary component of an overhead crane is the hoist, that’s attached to the trolley, and is used to perform the lifts. Several varieties of overhead cranes exist including gantry, semi-gantry, cantilever gantry, storage bridge and wall cranes.
Overhead crane safety is regulated by the Occupational Safety and Health Administration (OSHA) in 29 Code of Federal Regulations (CFR) 1910.179. This regulation covers overhead and gantry crane general requirements, design, inspection, maintenance requirements and operations.
General Requirements
Design Requirements
OSHA specifies design requirements on the construction of the cab and its controls as well as the cab’s lighting; foot-walks, ladders and stairways; bridge and trolley bumpers; hoist, holding, trolley and bridge brakes; electrical components; hoisting equipment; and warning devices.
Inspection Requirements
Due to the size and weight of the objects often being lifted and transported by overhead cranes, routine inspections are necessary to ensure continued safe operation. An initial inspection of the crane (new or altered) prior to initial use is required. Once placed into service, overhead cranes require two different types of inspections. Frequent inspections are done daily to monthly, while periodic inspections are completed at monthly to annual intervals. The purpose of the two inspection types is to examine critical components of the crane and to determine the extent of wear, deterioration or malfunction.
Frequent Inspections
Items to be Inspected | Frequency |
---|---|
Functional operating mechanisms for maladjustment | Daily |
Deterioration or leakage in lines, tanks, valves, drain pumps and other parts of air or hydraulic systems | Daily |
Hooks with deformation or cracks (visual) | Daily |
Hooks with deformation or cracks (written record with signature of inspector and date) | Monthly |
Hoist chains and end connections for excessive wear, twist or distortion interfering with proper function, or stretch beyond manufacturer's recommendations (visual) | Daily |
Hoist chains and end connections for excessive wear, twist or distortion interfering with proper function, or stretch beyond manufacturer's recommendations (written record with signature of inspector and date) | Monthly |
Running Rope and end connections for wear, broken strands, etc. (written record with signature of inspector, rope identity and date) | Monthly |
Functional operating mechanisms for excessive wear | Daily to Monthly |
Rope reeving according to manufacturers' recommendations | As recommended |
Periodic Inspections
Items to be inspected:
In addition to the initial inspection, OSHA also requires that all new and altered crane-functions are tested for:
Maintenance Requirements
A preventive maintenance program based on the crane manufacturer's recommendations must be implemented. If any deteriorated components or unsafe conditions are detected during the required inspections, they must be completed before the crane is allowed to be used. Only designated personnel may perform the required maintenance and repairs. The requirements of 29 CFR 1910.147, the control of hazardous energy or lockout/tagout, should be used to de-energize the crane (See Quick Tips #170: Lockout/Tagout for more information).
Операция
The manufacturer's instructions must be followed when operating to help ensure overhead crane safety. OSHA covers load handling requirements under 1910.179(n) and addresses the following:
Standard Hand Signals for Controlling Overhead and Gantry Cranes
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