HSE highlights loading arm risks

FOOT ON THE LADDER

LOADING ARMS • USERS NEED TO ENSURE THAT EVEN HARDTO-REACH PARTS OF MARINE ARMS ARE INSPECTED AND MAINTAINED, HSE SAYS, FOLLOWING A RECENT INCIDENT

THE UK HEALTH & Safety Executive (HSE) has issued a safety alert following an investigation into the collapse of a marine loading arm (MLA) that narrowly missed causing a serious incident. During that investigation, HSE found that not all components were being suitably inspected and maintained. In particular, in this incident, there was a problem on the top pivot joint, which had been missed because of difficulties in accessing that part of the arm.

The lack of lubrication of this greased joint presents a serious risk of the joint failing, with the potential for the complete collapse of the MLA. This could cause serious injury or even a fatality, along with damage to process equipment or pipework and a subsequent loss of containment.

HSE says that anyone using or servicing MLAs should check, review and identify inspection and maintenance work as required by the manufacturer and industry guidance. A plan should be developed to address how the work will be conducted, including accessing those parts that are difficult to reach, and that plan must be completed. Records should be kept and outstanding actions should be followed up.

WHAT WENT WRONG In the incident under review, the 8-inch nominal bore, hydraulically operated MLA had been in service for 11 years and had been regularly maintained by various recognised industry contractors. It had a rigid link pantograph balancing system with independent primary and secondary counterweights linked to the inboard and outboard arms.

The MLA failed as it was being manoeuvred towards a ship manifold for connection. A section of the MLA fell backwards onto a

ANY FAILURE OF A LOADING ARM HAS THE POTENTIAL TO

CAUSE INJURY, DAMAGE TO THE FACILITY AND EXTENSIVE

POLLUTION OF THE SITE AND NEARBY WATERS jetty handrail, narrowly missing live plant and pipework. The immediate cause of the failure was from corrosion of the bearing that led to a complete fracture, emanating from the circumference. The underlying causes were inadequate inspection and maintenance practices which had led to the corrosion.

There was no convenient means of accessing the pivot pin for inspection and maintenance. As a result, it had not been lubricated during servicing by several different contractors.

HSE has reviewed MLA designs and suggests that the problem of accessing all parts during maintenance may not be specific to one manufacturer.

HSE’s safety alert includes a call for action along the plan-do-check-act process. Following the planning stage, users are urged to inspect structural components such as the pivot pin and seals, ensuring they are in good condition, as soon as practicable. In light of that inspection, the inspection and maintenance programme should be updated to ensure that it is suitable and sufficient, and capable of detecting and remedying any foreseeable deterioration before it results in unacceptable risk.

Users also need to check that any maintenance work has been undertaken satisfactorily and that all risks are being adequately controlled. A clear, detailed and accurate record of the work should be made, highlighting any servicing requirements that are not carried out, along with a judgment about the potential impact.

Users then need to learn from what they have found, taking action as necessary, and implement any remedial action to address issues that have emerged. They should also review industry good practice and manufacturer’s guidance as well as inspection and maintenance plans periodically to see if they need updating.

HSE’s safety alert, available at www.hse. gov.uk/safetybulletins/marine-loading-armfailure.htm, also includes references to relevant legal documents and industry guidance.