This is an aspect which is often overlooked by both the employer using the crane and the inspection body.
By their very nature, fixed crane installations are high above the loads they handle and therein lies the first obstacle. Thinking back to when I started in the industry, many overhead cranes – particularly the higher capacity ones – had access walkways across the bridge. Typically they were cab controlled so there had to be an access ladder and landing stage on the gantry for the driver and that also gave access to the crane bridge. There were still many cranes with deep lattice girders and winch type crabs controlled by drum controllers. They needed regular maintenance, hence the walkways which also facilitated inspection.
The trend towards low headroom block type cranes with pendant or remote control has removed the need for driver access. Furthermore, headroom restrictions make it difficult to accommodate access walkways and the like. Other types of cranes used in factories, such as slewing jib cranes, rarely had the luxury of permanent access walkways. Using ladders has always had its drawbacks and limitations, particularly for access to anything with the potential to move or slew, but often they were the main method used.
Fast forward to the present day and improved safety standards, particularly reflected in the European Work at Height Directive, require a much more controlled approach to working at height from temporary access equipment. It is certainly possible for the inspection body to make their own provisions for working at height but, considering the geographical spread and variety of sites they are likely to work on, this is the least likely option. Most often it is the employer who is expected to provide the necessary facilities.
There needs to be cooperation between the employer and inspection body and this starts with both parties recognising the value of the inspection. Unfortunately this is not always the case. It is certainly true that inspection costs money and, after inspection, the crane is no better or worse than before. Some employers therefore regard it as a necessary and expensive evil. However, rather like insurance, it is actually essential to protect their interests. Following a good quality inspection, the employer will be far better informed about the condition of the crane and therefore able to decide about any corrective action.
Employers who do not recognise the true value of inspection are also likely to attract inspection bodies willing to cut corners to keep costs down. Such inspection bodies usually want a fatter profit for themselves to the extent that sometimes their fee for the inspection report doesn’t actually include visiting the crane, let alone inspecting it. Regrettably it happens – and is clearly a recipe for disaster.
Sometimes when an inspection is made, certain things are taken for granted which shouldn’t be. Structural elements of a crane can show no symptoms of deterioration for many years and, if access is difficult, they can easily be neglected. There are many modern technological aids to help the inspector but peering into the gloomy recesses of a factory roof with a pair of binoculars is not an adequate substitute for getting to see critical parts close up with good lighting etc.
Given an appropriate spirit of cooperation, the employer needs to consider how the inspector can safely gain access to everything that needs to be seen. Permanent access is certainly preferable and, if taken into account during the construction of a new facility, is likely to be cost effective. More often the situation is that of an existing factory or site which has evolved over the years. Temporary access is therefore the more likely solution.
The UK Work at Height Regulations which implement the European Directive are an example of modern risk based legislation. Although their legal status applies only in the UK, they are nevertheless a good model for emulation in other parts of the world. The concept underlying the regulations is similar to that of the European Machinery Directive in that there is a hierarchical approach to controlling risk. At the top is perhaps the most obvious choice of not working at height if it can be avoided. This is not often a practical option for inspection work. However, to illustrate the principle, consider a major refurbishment of a hoist. It could all be done at height but that might involve several people in an awkward location over a lengthy period. Alternatively it could be better to lower the hoist to the ground and reinstall it after refurbishment. Much of the inspection involved could be done on the ground with only the final installation inspected at height.
Given that work at height is necessary, the regulations guide you to the most suitable method for the particular work. Effectively there are three groups of equipment, scaffolding, mobile elevating work platforms and steps or ladders. Rope access equipment is also a possibility but unlikely to be suitable in the context of factory cranes and similar equipment. In deciding which is most suitable, the nature of the work, the duration of the work and the total risk are relevant. To explain the latter, if for example, scaffolding is used, the total risk includes the risk involved in erecting and dismantling the scaffolding as well as that involved in working on it.
Scaffolding using tube and clamps is ultimately the most versatile method but requires skilled personnel to design, erect and dismantle it. For simple applications on firm level ground, lightweight portable frame type scaffolding systems are suitable and have the advantage of being easily portable into the area. Mobile elevating work platforms are perhaps the quickest method of gaining access provided there is firm level ground and a suitable route into the area. They also have the advantage of providing easy height adjustment, useful when trying to inspect parts close up. However, depending on type, a degree of operator skill is required which may necessitate an operator accompanying the inspector.
Inspection is often quite a short duration process and in many cases does not involve much in the way of tools and equipment. Therefore steps and ladders are still the most appropriate for some inspection tasks.
Another aspect of inspection which is often overlooked is the need on some occasions to dismantle equipment. The problem quite simply is that, without X-ray eyes, the inspector cannot do the job properly unless the equipment is dismantled to some extent. Whether it is within the inspector’s remit to do the dismantling, or whether others are required to do it, is a matter between the employer and the inspection body. It may, in practice, be part of the preventive maintenance regime and timed to coincide with shutdowns or quiet periods to minimise disruption.
Dismantling may not be necessary for every inspection but may be appropriate on a regular basis at set intervals. For example, a structural component subject to long term corrosion or fatigue which is not readably visible might be made accessible by dismantling every four years. Alternatively, the need to dismantle might arise from the inspector noticing symptoms indicative of a potential problem, such as a noisy gearbox with excessive backlash indicating badly worn teeth.
Without the facility to get access to inspect close up and to dismantle when necessary, the inspection report can only reflect what the inspector was limited to. Therefore it cannot state with any certainty that the equipment is in a suitable condition to start another period of service. In such circumstances, what is the value of that report in informing the responsible employer about the condition of the crane?
About the author
Derrick Bailes is the chief executive of the Lifting Equipment Engineers Association, 3 Osprey Court, Kingfisher Way, Hinchingbrooke Business Park, Huntingdon, PE29 6FN, tel: +44 (0)1480 432 801, fax: +44 (0)1480 436 314, email: info@leea.co.uk
