In response to the concerns shown by the UK’s Health & Safety Executive, the National Federation of Demolition Contractors has produced a new set of guidance notes on the safe use of mobile crushers in a demolition environment.
As one of the co-authors of this work, I cannot be expected to give an unbiased rewiew of the publication. However, the following article does give an indication of the content.
Copies of the new guidance are available from the NFDC (www.demolition-nfdc.com)
Like the demolition and recycling sectors, the quarrying and mining sector utilises track-mounted jaw and impact crushers. Both use these highly specialised machines for materials reduction and processing purposes. And both industry areas require men to interact with these machines on a continuous basis. But that, largely, is where the similarities end. While most demolition sites are transient and short-term, mines and quarries remain fixed for prolonged periods of time, allowing mine and quarry operators to set in place measures to protect their workforce from falling into the crusher chamber or from being struck by material ejected by the crusher. Mines and quarries are usually large, open areas unencumbered by obstacles, unlike demolition sites where space is often at a premium. And the quarrying sector has experienced fatalities from the incorrect use of mobile crushing equipment while, thankfully, the demolition industry has been rather more fortunate.
Against this background, the National Federation of Demolition Contractors was quick to react when the Health and Safety Executive issued its own guidance notes on the safe use of mobile crushers. “As with any item of legislation designed to improve the safety of our workers, we welcomed the HSE’s initial guidance notes and we generally supported them when they implemented the rules and served some demolition sites with prohibition notices when they found operatives on the crushers while they were working,” says NFDC chief executive Howard Button. “But we were also extremely conscious that the HSE guidance had been written largely in response to injuries and fatalities in quarry applications and that some of their recommendations would prove difficult or impossible to adhere to within a demolition environment. That is when we decided to produce our own demolition-specific version.”
To assist in the process of producing the new guidance notes, the NFDC enlisted the help of Federation associate member Sandvik Mining and Construction, a recognised leader in the field of mobile crushing and screening equipment and the owner of both Extec Screens and Crushers and Fintec Crushing and Screening. “We used the HSE guidance as our starting point but we knew that the machines and the way they’re used differs somewhat in the demolition and recycling sector so we wanted the input of a company with a foot in both camps,” Button continues. “A surprisingly large number of NFDC corporate members currently run Extec and Fintec machines so Sandvik seemed to be the most sensible company to partner us.”
The resulting document is a punchy, quick reference that addresses all the key issues of safety surrounding these highly productive and yet potentially hazardous machines. “In the right hands, a mobile jaw or impact crusher is a highly productive piece of equipment that is every bit as common in the demolition arena as a high reach excavator,” says Sandvik’s global product line director John Nethery. “But without proper planning or training, these machines do have the ability to cause injury. As a leading supplier of this equipment, we were delighted to have been invited to participate in helping address these important safety issues.”
The new guidance notes, which will be issued to NFDC members immediately after the NFDC 2008 Convention in Majorca at the end of August, identifies and addresses all the key risk areas including machine guarding, clearing blockages, slips and trips, and the interaction with the loading machine. The guidance also addresses the most contentious of all the original HSE guidance; the presence of a person on the crusher’s operating platform while the machine is working. “The recommendations in the new NFDC guidance makes it very clear,” Nethery continues. “A properly designed mobile crushing operation should not need any person to be present on the crusher access platform during normal crushing operations.”
Multitude of Risks
Nethery asserts that any person on the platform during operation faces a multitude of potential risks including being struck by objects ejected from the crusher; being pulled into the crushing chamber when attempting to pull out contaminants or oversize material; being struck by an excavator or wheel loader bucket; and exposure to noise, dust and vibration.
“One of the key areas of concern for us as a manufacturer of this equipment is the issue of Whole Body Vibration,” Nethery says. “Anyone working on a mobile crusher while it is in operation could be exposed to constant, low-frequency vibration that should be avoided.”
Nethery believes that the primary reason operatives have traditionally stood on the operating platform is to tackle blockages and bridging. But he further believes that this can be avoided through thorough pre-selection of materials and via the use of stand-alone and isolated picking stations to prevent blockages, and boom-mounted breaker booms to remove them when they occur.
“Demolition contractors are generally excellent at materials segregation, partly because they truly understand the value of the materials being recycled but also to protect their crushers from tramp metal and oversize material,” John Nethery concludes. “By ensuring that such vigilance is the norm and by following the advice of the new guidance notes, demolition contractors can remove the need to put a crusher operator in harm’s way altogether.”