Following many investigations, Mr. Ivan Todorov, Senior Master Mariner at Brookes Bell Singapore has found that human error element is commonly not addressed when talking about crane rope failures. Beyond the common causes such as wire fatigue and overloading, there is usually a human error behind these causes. In the following article, Mr Todorov delves into how the human element is neglected, and what are some of the unsafe practices that can lead to crane rope failures.
In 2018, the crane failure on the Atlantic Giant II highlighted how the decision to lift beyond the planned weight with no proper risk assessment ultimately resulted in an estimated $6.4 million worth of damages. Three people were injured, and the load and crane boom fell into the harbour as a result.
This is a typical example of a crane failure resulting from mishandling, and other cases might arise from component failure and ineffective maintenance practices. Crane failures can lead to damage to ship structures, loss of cargoes, lengthy loading and discharge delays – floating barge cranes may even be required to complete operations. Most importantly, they can potentially endanger those nearby and may even lead to the tragic loss of life.
Crane wire rope failures are typically caused by fatigue and overloading. However, as highlighted by the Atlantic Giant II example, there is usually an underlying human error element involved.
I have seen cases where wires have not been renewed for almost 10 years – quite an excessive period of operational time that is likely to cause a potential incident. Some companies do not have detailed maintenance and inspection policies and they tend to rely on reactive maintenance instead. This is short-sighted as any failure is likely to incur hefty costs.
Instead, a proactive maintenance programme is far more appropriate, and this usually involves periodic and pre-operation inspections of wires, bearings and sheaves, including the crane’s hydraulic pumps and motors. Details can be found in the crane manufacture manual, which will explain how often and thoroughly they should be inspected. These items should all be included in a comprehensive planned maintenance system to maximise crane availability, and they should be reviewed regularly by technical managers to ensure their effectiveness.
Beyond proactive maintenance, failure to properly operate the crane can result in catastrophes too.
Cranes are to be operated by trained vessel personnel or stevedores, but complications can arise when they are working under time pressure or have not received proper familiarisation of the crane condition.
Vessel cargo operations will always be carried out with time constraints, but these can be exacerbated when a port tries to make up for lost time due to bad weather or delays. To speed up the operation, stevedores may occasionally perform the lifts at an angle as opposed to the usual vertical lift.
Lifting at an angle is not allowed by the manufacturer. In some cases, lifting at 1° or 2° is allowed by the manufacturer, but this may not always be safely observed, and doing so increases the risks involved, as lifting from an angle decreases the effective loading limit of the crane.
Furthermore, the hoisting wire of the grab may be mechanically damaged when this is performed, particularly when an attempt to reach the under-coaming area is made. Although the wire may not necessary break immediately, it may fail at a future point.
Mishandling can happen when there is a lack of communication between the crew and the stevedores. Good dialogue between the crew and stevedores is necessary before and during any operation so that the two parties can reach a mutual understanding on the requirements to operate cranes and how to jointly expedite the cargo operation. There should also be a supervising member of crew or stevedore in attendance during operations.
The signalman or supervising crew must flag up any mishandling during the operation and stop it, to prevent any potential incidents or accidents. Similarly, stevedores should highlight any triggered alarms or any unlikely bypassed safety devices to the crew and rectify the issue before continuing.
However, in the unfortunate event of a crane failure, it is important to obtain contemporaneous forensic evidence at the scene as soon as possible. This will help expedite any claim settlement in the event of a dispute, and is why we always advise clients to engage us early as it can make their case less costly.
It is crucial to seek out a multidisciplinary team of master mariners, marine engineers and metallurgists who can provide prompt and accurate preliminary advice to reduce loss of time and cost of failure. This is then followed by detailed forensic analysis and testing to determine the root cause in any individual case.
Depending on the severity of the incident and availability of spare parts, crane failures can take anywhere between four to five hours and several days (and even months) for repairs to be completed, with alternative arrangements being dependent on availability of local assets.
However, the adage “prevention is always better than cure” still holds true. Shipowners and charterers looking to avoid costly claims and disputes, should seek recommendations on preventive maintenance to significantly reduce the likelihood of a crane failure.
The views presented hereabove are only those of the author and not necessarily those of SAFETY4SEA and are for information sharing and discussion purposes only.
Ivan Todorov is a Senior Master Mariner. He joined Brookes Bell in November 2014 following 4 years commercial experience, 15 years sea-going experience and 9 months as Marine Safety Quality Superintendent. He became an Associate for Brookes Bell in May 2017. He sailed as master for 5 years on board Aframax and VLCC tankers for Sanko Ship Management. He has also served on product tankers, bulk carriers and general cargo vessels. During a year’s secondment period with KOTC, Fleet Operations Group, he was responsible for operation and post-fixture of 4 VLCCs, 3 product tankers and 2 LPG carriers.
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