Forward tipping dumpers, also known as site dumpers, play an important role on many construction sites, transporting and redistributing spoil and materials to different locations. Yet a large number of incidents during dumper operations have led to serious injuries and, tragically, fatalities. “Not only do these accidents have a terrible cost in terms of human suffering, they also have a significant emotional and financial cost for all concerned,” states Kevin Minton, chief executive at the Construction Plant-hire Association (CPA). “There is, therefore, a very strong business case for improving safety performance.
“Using dumpers safely depends on a number of factors, including planning, supervision, selection of a suitable machine, competence of personnel, effective exclusion zones and keeping within the operational limits of the dumper,” he adds. “If any of these are deficient, the risk of a serious accident increases significantly, and it is, therefore, essential that all of those involved ensure that dumper operations are properly planned, managed, supervised and carried out safely by competent people.”
It’s something that has also caused deep concern among the Civil Engineering Contractors Association (CECA), prompting the two associations, along with input from the Health and Safety Executive (HSE), to develop new guidance that is aimed at tackling the increasing number of dumper incidents that, says CECA chief executive Alasdair Reisner, “were leading to untimely deaths”.
Working in partnership through the Strategic Forum for Construction Plant Safety Group, the CECA and CPA have come up with a seven-point strategy that forms part of new guidance aimed at mitigating future dumper incidents (www.is.gd/oyesap).
What approach would they advocate, if dumpers are to be used safely and efficiently? As with all construction equipment, states the guidance, selection of the most suitable machine, effective planning and supervision, together with competent people, is essential. “Unfortunately, some of the large number of dumpers in use are operated incorrectly or put into unsafe situations,” it points out, “often resulting in accidents and incidents that sadly cause serious injuries and death.”
The guidance cites many instances where such accidents have transpired. In one example, a dumper operator was driving his fully-loaded machine down an incline when it overturned. The operator, who had not been wearing a seat belt, was thrown from the dumper, which landed on his legs and crushed him. He was airlifted to hospital where surgeons amputated both legs near the knees. An HSE investigation found there were several failings that led to the incident. The specific type of truck being used was not appropriate for the task, while the limitations of the equipment had not been assessed and recognised. The contractor had also not “carried out an assessment for any of their drivers or their competence” in using the equipment.
In another incident, an operator was driving a forward-tipping dumper, which became stuck on a spoil heap. The operator jumped off the dumper, which then flipped over and caused serious head injuries to the operator, who subsequently died as a result. An investigation found that there were no ‘stop-blocks’ in place to prevent over-running. It further found that an excavator had removed some of the spoil heap, which created a sheer face.
The first piece of advice offered in the guidance is that dumpers should not be specified where more effective or safer plant, equipment or methods can be used. Moreover, “dumpers are designed in principle to only carry bulk materials contained securely within the skip. Other types of use, or where loads exceed the confines of the skip, should not be carried out, unless risk-assessed and in accordance with the machine manufacturer’s specifications”.
Site managers, supervisors and operators of dumpers should understand the principles of safe operations and the potential for mishap, the guidance continues, and have a legal duty to ensure that all dumpers are used safely. “Serious misuse of dumpers contravenes the Health and Safety at Work etc. Act 1974 (www.is.gd/nevoco), which could well lead to an individual prosecution.”
A major concern where dumpers are concerned is that they have a high centre of gravity, particularly when loaded, and can be prone to overturning on steep inclines, soft or uneven ground. A full load also reduces forward visibility significantly, increasing the risk of collisions with people. objects, structures or other plant.
The guidance points to how many dumpers currently in use have an open operator’s control station, which, in the event of an overturn, relies on the operator wearing a seat belt to keep them within the protective area of the rollover protection structure (ROPS). “Research shows that some operators believe that they have a better chance of survival if they do not wear a seat belt, so that they can jump clear of the overturning machine. Analysis of dumper overturning incidents indicates that operators were not able to jump sufficiently clear and in time, and have been crushed by their own machine.
“Those wearing seat belts have been shown to survive (with minor injuries), rather than die. The non-wearing of seat belts during dumper operation should be of concern to both employers and employees.” However, it is also acknowledged that a site-specific risk assessment may indicate that seat belts should not be worn in certain circumstances, such as when operating next to water.
One especially hazardous aspect of dumpers is where they are operated on spoil heaps, which can lead to instability and overturning. “Industry safety initiatives advocate the banning of this practice wherever possible. If there is a need to travel on spoil heaps, designated and engineered routes that have been pre-compacted and are away from the edges of the spoil heap must be provided,” the guidance adds.
BOX OUT: To cab or not to cab
The use of dumpers fitted with a cab is becoming common place as an aid to providing a comfortable environment for the operator during operation. Some cabs may, however, restrict all-round visibility when compared with non-cabbed versions.
Additionally, not all cabs may provide the fully-required impact protection, including against broken glass, to allow the operator to remain in the cab during the skip-loading process. Before permitting this practice, managers and supervisors should check the level of protection afforded by the cab against operating circumstances, for example, the size and type of loading machine against manufacturer’s specifications.