There are three key terms used in reference to the regulations.
Factor of safety overhead lifting equipment.
Lifting equipment must be of adequate strength for the proposed use.
Manufacturers for overhead lifting equipment will list hardware by their rated loads and mention safety factor used.
Example structural steel column in a building.
Lifting equipment is any work equipment for lifting and lowering loads and includes any accessories used in doing so such as attachments to support fix or anchor the equipment.
Components of the multiple lift rigging assembly shall be specifically designed and assembled with a maximum capacity for total assembly and for each individual attachment point.
Other terms frequently used for design factor are safety factor factor or safety.
For overhead lifting safety factors are 5 0 on ultimate and 3 0 on yield.
Definition of design factor.
Overhead cranes and their supporting runways patient.
Marking system of safe working load.
The assessment of this should recognise that there may be a combination of forces to which the lifting equipment including the accessories will be subjected.
F allow allowable load n lb f.
L ifting operations can often putpeople at great risk of injury as well as incurring hefty costs when they go wrong but factors of safety fos for lifting equipment is not.
It is a calculation of the minimum breaking strength mbs aka minimum breaking load mbl divided by a safety factor usually ranging from 4 to 6 on lifting equipment.
Examples of lifting equipment include.
Fos factor of safety.
It is always greater than 1.
This capacity certified by the manufacturer or a qualified rigger shall be based on the manufacturer s specifications with a 5 to 1 safety factor for all components.
Usually marked on the equipment by the manufacturer.
Lifting equipment should have a tally plate indicating the safe working load.
The factor can be as high as 10 1 or 10 to 1 if the equipment poses a risk to a person s life.
F fail failure load n lb f.
The design factor is the ratio of the minimum breaking strength to the permissible working load.
Factors of safety fos are a part of engineering design and can for structural engineering typically be expressed as fos f fail f allow 1.
It must be clearly marked on any lifting device hoist lifts lifting machines and lifting tackles.
Due to buckling the failure load of a steel column in a building is estimated to 10000 n.
Breaking strength is the rigging material or hardware s tensile strength in lifting and pulling operations.