One of the most important ways to keep your crane working properly and the people around it safe is to perform regular testing and examination, not just of the crane itself, but of the equipment you use with it. Recently, the advice on the best way to do this has changed in two key ways.
We cover the first of these issues, overload testing, in detail this month. For many years, the shared wisdom among crane users, clients and regulators has been that the best way to test a crane is to overload it.
That advice no longer stands. As Cristina Brooks finds out in this issue, experts now agree that overload tests should be kept to a minimum.
There was a time when a crane that had passed an overload test could reasonably be considered safe to use. Nowadays, cranes are increasingly built with fine grained steel. Manufacturers calculate their working life based on a limited number of overloads. When this sort of modern, highly-optimised crane is overloaded, the test itself may damage the crane to the point where it will suffer a structural failure the next time it is used.
The expert advice today is that overload tests should only ever be carried out when a crane is first manufactured, or when structural components have been repaired. Even then, the overload test should always be followed by a thorough examination, to ensure no damage has been done to the structure.
Some regulators and clients, however, still demand that the tests are carried out. An FEM policy paper, coming out shortly, will update the manufacturers’ advice on overload tests. It should be a useful document for those times when you need to convince a customer that regular inspection and thorough examination is the best way to check a crane is safe, rather than overload tests. It will, hopefully, also provide a reference for regulators in their ongoing discussions with the industry.
The second change comes with the introduction of a revised ISO standard, ISO 4309:2010, for wire rope visual inspection. As one expert explained to me, the new standard recommends an assessment of rope condition based on wire breaks, rope diameter, the degree of deformation and damage and corrosion levels both internally and externally.
The changes to this advice are complex, and should be given careful consideraration by anyone responsible for wire rope inspections. It is a topic we intend to look at in more detail in upcoming issues.
