One of the biggest sources of crane misinformation relates to the requirement for a Major Inspection. Many service providers simply state that a Major Inspection is required when the crane has reached 7 years of age and recommend a full strip down and overhaul.
This is flawed on two levels:
- Crane design life is based on usage not calendar life.
- The required scope of a major inspection can vary greatly depending upon the type, age and working environment of the crane.
Each crane is designed for a certain number of lifts, for example a C3 crane to the current AS 1418 design standard has a design life of 32,000 full load lifts. This life roughly doubles for each additional crane class so that a C4 crane has a life of 63,000 full load lifts*.
Equally important is the percentage of rated capacity that the crane lifts. Consistently lifting less than the maximum rated capacity will greatly extend the design life. For example a C3 crane which only ever lifts 50% of its rated capacity will increase its allowable lifts from 32,000 to 256,000 cycles.
The Australian Standard for safe use of cranes (AS2550.1 – 2011) only requires a Major Inspection to occur after 7 years of use when the current crane life has notbeen assessed.
Cranes shall be subjected to a major inspection to assess their suitability for continued safe operation as follows: (a) Unless assessed in accordance with Section 9 to determine when a major inspection is due, after two-thirds of the design life specified by the manufacturer or the original design Standard or, where this is unknown after 7 years of use.
However the standard also requires that an annual third party inspections take place which include an assessment of crane life. Therefore any Australian Standard compliant crane management program requires the crane life to be assessed annually and will have a documented calculation of how long until each cranes design life has elapsed. Generally this will be far in excess of 7 years.
This compliance requirement also makes good financial sense. As the initial capital outlay is the most significant crane life cycle cost any increase in asset life has a corresponding decrease in real annual cost.
Our experience at ideas* cranes is that the usage of the majority of overhead cranes we review allows them to have a calendar life far in excess of the nominal 10 or 25 years. Unfortunately we also often review cranes where costly overhauls have taken place which where completely unnecessary. To extend your crane assets life and minimise unnecessary costs we recommend:
- Implementation of an annual independent 3rd Party Inspection program. This is the simplest method to ensure your crane compliance processes are up to standard and to plan for Major Inspection activities.
- Always obtain independent advice before completing a Major Inspection.
*Note that the allowable life is dependent upon the method used to estimate lifts. Installation of a data logger can increase the crane life by up to 50% over other estimation methods.