27.08.2010

HSE warns of cranes in high cycle applications

The UK's Heath and Safety Executive has issued a warning via a letter to the Contractors Plant Association, highlighting potential problems of using cranes in high cycle applications, following an incident in Aberdeen when the boom of a mobile crane 'snapped'.

The incident in Aberdeen harbour was recently investigated by the HSE and involved a conventional 100 tonne mobile crane being used for loading supply vessels. The crane undertook in excess of 117,000 lifts over a three year period and was only three years old when the boom snapped in half whilst lifting a container.

Fortunately no one was hurt during the incident. The letter is printed in full below and summarises the HSE's findings and guidance to hire companies that may be supplying cranes for this type of work.

HIGH CYCLE LIFTING OPERATIONS WITH MOBILE CRANES

The Health and Safety Executive have recently investigated the boom failure of mobile crane being used at a harbour to load a supply vessel. The boom fractured and the load being lifted fell on the vessel deck. Fortunately no one was injured.

Examination of the failure surfaces identified extensive fatigue cracking. Records held by the user identified that the crane had undertaken in excess of 117,000 similar lifts at the harbour over three year period since the crane was purchased.

The design standard for the mobile crane manufactured in 2006 was BSEN13000:2004. This standard referenced a German Standard DIN15018-3 with respect to the in-service design life and gave a design life of 25,000 lift cycles. Thus the incident crane had significantly exceeded the manufacturer’s design life.

The Provision and use of Work Equipment Regulations 1998, Regulation 4 requires that an employer ensures that work equipment is so constructed as to be suitable for the purpose for which it is provided. The suitable selection of equipment will reduce the risk of persons being harmed.

Where a large number of high cycle lifting operations are to be undertaken consideration should be given to the type of crane to be selected. Mobile Harbour Cranes, Portal Jib Cranes or Overhead Bridge and Gantry cranes may be more suitable for high cycle lifting operations than a conventional mobile crane.

The Lifting Operations and Lifting Operations Regulations 1998, Regulation 4 requires that an employer ensures that lifting equipment is of adequate strength for the proposed use. This includes consideration of failure by fatigue or wear.

Where cranes are being used in high cycle applications it is important that crane owners monitor and record the cycles that their cranes are undertaking and make amendments to the inspection, maintenance and thorough examination programmes. The crane owner should seek advice from the crane manufacturer as to revised inspection and maintenance procedures.

This may include replacement or overhaul of parts that have exceeded their design life. The owner should inform the competent person undertaking thorough examination that the crane has been and will be used on high cycle work. The competent person may request supplementary examinations to be undertaken in support of thorough examination.

These may include Non Destructive Testing, strip down of assemblies such as slew rings, booms and winches. The competent person may also decide to increase the frequency of subsequent thorough examinations by reducing the period to the time of next thorough examination.

As you are aware guidance on the Inspection, Maintenance and Thorough Examination of Mobile Cranes is available for down load from your web site.
In this incident no one was hurt or injured however the consequences could have been much more severe. I would ask you to bring the matters contained in this letter to the attention of your members.

Yours sincerely


Ian Simpson
HM Principal Specialist Inspector of Health and Safety
Mechanical Engineering Specialist Group – North