Crane Testing and Derating

It depends on maintenance procedures, if the crane is well maintained there should be no need to de-rate. Corrosion would be the only reason I could think of.

Are the cranes inspected by out side body? Most UK cranes are, otherwise they can't be insured.

The standard method for crane evaluation is the <14 months inspection by the Engineer/Surveyor from the company providing crane collapse indemnity insurance cover. This individual determines the derating to be applied, if any, on the basis of the crane's condition at the time of inspection.

The reports should all be filed in a General Register, which needs to be available for his/her review at each inspection.

In India there is Indian Standard IS:3177 for overhead travelling cranes. It prescribes annual testing method for these cranes. Also there are local factory inspectorates who have laid down mandatory testing of the cranes.I do not know which country you belong. Normally cranes are tested for 25% overload and you have to check if all the important components such as brakes, limit switches, motors, gear boxes, wire ropes etc are in proper condition.Also crane structure is subjected to deflection test and it should be 1/900 of the span. I will not recommend you to de rate the cranes.

It is known that there are international as well indian standards for design fabrication and testing of cranes. But these standards are for new cranes, they do give a check list for periodic inspection. During annual crane testing mechanical components get tested and maintained/ replaced but what about structural components both incase of EOT and mobile cranes? Further bridge deflection tests indicate limiting conditions for design and acceptance which is a go/ no go test.

Some procedures need to be established for cranes to access safe capacities of old cranes just load tests may not be enough.

readers may advice

There is some important data you must but in your consideration.

1st. The type of load if it's Persons or imprtant things or normal things.

2nd. The operating condition Tough or normal.

3rd. I don't Know Exactly in which standard you could found this but i think BS 7121 Could be helpfull