2.1 Stability criteria
In the design of equipment and vehicles it is common to use safety factors to ensure that dynamic
effects and wear do not compromise the safety of structures in use. Building crane structures typically have a
safety factor of around 6 - that is they are designed to withstand 6 times the rated lifting load – and chains
and slings have a safety factor of around 4. Heavy trucks have safety factors of 3.5 - 5.0 in relation to
vertical loads, and trailers a safety factor of 2.5. Chains and webbing used to restrain loads on trucks have
safety factors around 2.0.
Engineering safety principles in relation to the stability of counterbalance forklifts trucks are expressed
in the testing regime prescribed by the ISO Standards, which is related to the risks of tip-overs, roll-overs,
and loss of loads.