Within the lifting industry – and beyond – there is growing concern over the risks posed by age-related crane failures. In response, LEEA is seeking to highlight the need for effective measures to be put in place to identify and assess the critical components that will degrade over a crane’s life, and replace or overhaul them before they present a danger to health and safety. LEEA is also keen to stress that ultimate responsibility for making sure this is done invariably lies with the duty holder: the employer or self-employed person providing lifting equipment for use at work, or the person in control of use of lifting equipment.
All cranes have a finite lifespan
Overhead cranes typically serve a long working life. Indeed the majority are designed to operate for between 10 and 20 years. However, duty holders must always bear in mind that all will reach a point at which they are no longer safe to use. Furthermore, to ensure proper monitoring of the aging process, additional measures must be put in place that go beyond routine periodic maintenance and thorough examinations. To this end, support can be found in the form of the standard BS ISO 12482: 2014 Cranes – Monitoring for crane design working period.
The starting point for an effective monitoring programme is an understanding of the original lifespan of the crane. This should be established at the design stage of every new crane, based on the operating conditions. The information shared between the buyer and manufacturer to enable this will include the total number of working cycles to be carried out, the load spectrum, and the average displacements. From all this data, it is possible to establish a classification for the crane, and then design it for the intended lifespan, known as the Design Working Period (DWP). Another international standard, ISO 4301 – 1: 2016 Cranes – Classification, provides manufacturers and buyers with a common framework and reference for this entire process.
Inevitably though, the assumptions on which a crane is originally designed will often change in practice. As a result, the operating life becomes an unknown variable. Indeed, even if the original data on which the crane is initially designed is observed to the letter, the operational life defined by the manufacturer must always be treated as an estimate, not a certainty.
Signs of aging are not always obvious
To further complicate matters, many of the signs of ageing are either difficult or impracticable to identify with routine procedures. For example, problems with hoists may only be revealed by a complete strip down - not something that will typically be encompassed by standard inspection/maintenance regimes or a periodic thorough examination. In most cases, the sensible policy is therefore to monitor the lifecycle of safety-critical components, and either replace or overhaul them as appropriate once they reach the end of this period.
Ultimate responsibility always lies with the duty holder
There is no doubt that designing and implementing an age monitoring system can be a complex task. As with maintenance and thorough examination, employers may choose to outsource it to an external supplier. But it must be stressed that doing so does not absolve them of responsibility. It simply changes the nature of their accountability. In particular, that means ensuring all the tasks necessary are undertaken by suitably trained and qualified personnel. To do so, they must have a clear understanding of who does what with regard to monitoring the DWP.
The competent person, inspectors, maintenance and operating personnel all have a role to play
In the UK at least, most readers will be familiar with the requirement, under LOLER (Lifting Operations Lifting Equipment Regulations), for periodic thorough examination of lifting equipment by a competent person. As already mentioned, for many safety-critical components, it is often difficult for the competent person to undertake a visual examination without significant disassembly. In some cases, this is simply not practical. The competent person must therefore employ other investigative techniques. Typically these will include reviewing the machine history file, manufacturer’s literature, and the current application and utilisation. This information can then be used to ascertain the appropriate actions needed, when compared with measurable information such as the DWP.
It should be noted that the competent person is not necessarily responsible for assessing the DWP, disassembling the crane, or overhauling it. However, they are responsible for identifying defects and potential defects due to a shortfall in the maintenance regime or changes of use, and reporting these issues, along with the timeframe in which they need to be actioned, to the duty holder.
The inspector is responsible for the interim inspections that should take place between thorough examinations, as determined by the risk assessment. The risk assessment should be based on a range of factors that include the DWP, to identify the critical components and assemblies to be inspected, and the frequency of these inspections. However, it is important to note that the inspector is not necessarily responsible for completing the risk assessment. It is the duty holder’s responsibility to ensure that one is done, and that the personnel to whom it applies are competent.
Furthermore, the inspector is not necessarily responsible for disassembling the crane or undertaking a major overhaul. But it should be noted that inspections are often done at the same time as planned maintenance and, in some cases, the inspection and maintenance personnel are the same. In all cases, the inspection personnel must maintain records of each inspection completed and ensure that any findings, recommendations or urgent actions are reported to the duty holder and made available to the competent person.
Maintenance personnel are responsible for maintenance and repairs requested by the inspector or competent person, required by the manufacturer’s literature, or in accordance with a planned maintenance regime defined by the risk assessment. Planned maintenance would include a major overhaul when the DWP of the crane has been reached.
Maintenance personnel are not necessarily responsible for assessing the DWP, but they do have a responsibility to ensure that one has been defined and that they work to it. Maintenance personnel should keep records of all maintenance activities in the form of a machine history file. This should be made available to the competent person, as required.
Operators’ responsibilities include pre-use checks of equipment. They should report any changes in the operation of the crane that might indicate a defect to the inspector/maintenance personnel. In terms of the DWP, this should extend to carrying out any monitoring and reporting required to identify when the DWP limit has been reached.
Finally, given that cranes are often refurbished, modified and traded second hand, crane modifiers may also have a role to play in terms of taking responsibility for assessing it in terms of the DWP, based on the agreed utilisation and original manufacturer’s literature.
Continued safe operation should never be taken for granted
Overhead cranes have established a reputation as highly durable workhorses across a wide range of industries. The subsea and offshore sector is no exception. However, their continued safe operation should never be taken for granted. Unfortunately, the age-related failures that have recently come to the attention of LEEA suggest that at least some employers are either not grasping the potential risks, or failing to implement the additional procedures necessary to address them. In addition to raising awareness, LEEA is therefore in the process of writing a guidance note that will help all the relevant parties understand and fulfil their obligations. Ultimately, however, the key message for duty holders is very straightforward: effective on-going monitoring of age-related issues is vital to prevent the potentially devastating consequences of sudden and catastrophic failure of safety-critical crane components.