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In an interview with HANSA, Chris Dyson, a senior partner and marine engineer at Brookes Bell, discusses the causes of crane failures, and how affected parties should respond to incidents

What are the common issues that lead to a ship’s crane failure?

Chris Dyson: When a ship’s crane[ds_preview] fails – most commonly during lifting operations – there are many possible issues that could have contributed to its failure. The most common cause of incidents is wire failure; other incidents investigated by Brookes Bell include those triggered by slew bearings that have been neglected during service and sheaves that have not been regularly greased.

From a human perspective, mishand­ling the crane or swinging its load can also cause damage, which can have major implications in worst case scenarios. Misconceptions about a crane’s maintenance regime have also lead to failures. For example, manufacturers can describe a number of key crane components as »maintenance free«. However, Brookes Bell have investigated crane failures that have been caused by such components which still require periodic overhaul. Individuals have interpreted manufacturer’s guidelines and assumed that certain crane components do not require any maintenance during their lifecycle.

Has the number of incidents increased?

Dyson: While there is no widespread data on the precise number of incidents, it is likely that the number of major casualties is decreasing. P&I clubs underline that they have been quite active in loss prevention, for example. Notwithstanding this, Brookes Bell still investigates around 30 incidents per year.

What is the impact of a ship’s crane failure?

Dyson: Ship’s crane failures can have a costly impact on ship owners, operators, stevedores and seafarers. When a crane fails, many elements can combine to increase the impact of the incident. These elements not only include upfront damage costs, but also the impact of injury, or even death, as well as costs and time lost as a result of the crane being taken out of service while the incident is investigated and repairs are completed. Other commercial implications can also result from crane failures, for example, when a crane is out of service ship owners can incur additional costs because the cargo gear is no longer as described in the charter party and the ship cannot fully comply with its contractual specification.

These elements, as well as other factors unique to each case, mean that even a crane failure that is initially perceived to be a small matter can, and often does, quickly escalate when the consequences of the incident are fully evaluated and assessed.

How should ship’s crane failures be investigated?

Dyson: While there are a lot of commonalities between crane failure cases, each case is unique and demands a best practice investigation approach that combines theoretical analysis and a practical assessment of the scene.

From the outset, mobilising the right experts on site is critical and will ensure early evaluation and preservation of vital evidence that will, in turn, assist in the efficient conclusion of a crane failure dispute. While surveyors are regularly sent to investigate a crane failure, they are unlikely to be crane experts. The individual mobilised on site should have in depth engineering knowledge as well as access to metallurgists, tribologists, naval architects, and other specialists that may be required to analyse and provide expert opinion on aspects such as corrosion, materials, wear mechanisms, vessel stability and the numerous other factors that can influence crane failure.

What do you suggest to prevent crane incidents?

Dyson: A ship’s crane is an integral part of the ship that should be given the same priority as any other machinery, whether it is in use all of the time or infrequently. Although the crane is not in use at sea, its ropes and other elements can still be subject to degradation caused by the marine environment, which can eventually lead to failures. To minimise the risk of failures, ship owners and operators should follow a planned maintenance regime for the inspection and care of cranes, the requirements of which they should strictly adhere.

Furthermore, in my personal opinion, a positive step forward could be the inspection of a ship’s crane by the manufacturer or a specialist crane service engineer on a five yearly basis. These inspections should be inclusive of the crane’s hydraulic pumps and motors. One suitable way for the crane operator to assess the internal condition of the hydraulic pumps and motors is via hydraulic oil analysis. This involves sending a sample of hydraulic oil to a shore-based laboratory where it can be examined for contaminants and wear debris. If internal wear is suspected, ship owners can then take suitable measures to address the issue.

Interview: Thomas Wägener

Thomas Wägener