Hand-arm vibration: testing times

Headlines have been made recently by the Major Contractors’ Group’s (MCG) decision to require hand tools used on its sites to be submitted for independent, real-life vibration testing. For a start, not all manufacturers have been happy to comply with the request. Some highly respected companies have reportedly been temporarily blacklisted by the MCG for refusing to comply.

The potential disruption to the supply chain on some of the construction industry’s largest projects were such major brands spurned would have been considerable. Yet the MCG has made it clear it is willing to persist in its stance.

“We’re well on target,” says MCG Director Stephen Ratcliffe. “We’re not aware of any major omissions, nor of any problems. By and large, the major manufacturers and hirers have been supportive of this initiative.”

Why is it so important to the MCG to establish a new testing regime when, as many manufacturers are only too keen to point out, European legislation, through the supply of machinery regulations, already sets a testing standard? The answer stems from their position as employers, and another set of European legislation that determines their responsibilities to their workforce. In particular, the requirement to carry out robust risk assessments of potential hazards is crucial.

“There’s a lot of hand-arm vibration (HAV) exposure on construction sites,” Ratcliffe continues. “The way to deal with this for our members is through the establishment of a robust, independent testing regime.”

“The argument that current testing is sufficient doesn’t necessarily satisfy us with regards to what we need for risk assessments,” adds Mark Owen, Safety Manager of Shepherd Construction and vibration specialist at the MCG. “We can’t do these properly without productivity data.”

This productivity information is the crucial element of the testing regime desired by the MCG. “It is clearly essential,” explains Dr David Edwards, Founder of the Hand-Arm Vibration Test Centre (HAVTEC) at Loughborough University, which conducts much of the testing on the MCG’s behalf. “Employers are subject to their own legislative requirements under the Physical Agents Directive, which requires a risk assessment to be made, and this in turn requires real-life, in-use data involving productivity testing for a robust risk assessment. A risk assessment requires a performance assessment.

“A tool may have low HAV test results, but if it’s completely ineffective at a given job and needs to be used far longer than an effective alternative, you may end up with higher vibration exposure levels,” he continues. “One drill may have a vibration level in operation of only 10m/s2 (metres per second squared), but can only drill 20 holes in half an hour. Using this would result in far greater exposure than a tool with a level of 15m/s2, but that can drill 150 holes in quarter of an hour.”

Yet this is precisely the kind of data that is not available from the vibration testing currently required of manufacturers.

“This is because they are required to submit their products for comparable testing based on only one or two applications, none of which is conducted in ‘real-life’ situations,” says Edwards. “The question you have to ask is whether a test of a tool in a bucket of ballbearings will allow you to assess vibration risks sufficiently to really protect your worker, as you have an obligation to do.”

The MCG thinks not, and while it is conscious of concerns raised by manufacturers and others that localised testing can prove a major headache in a free market, it says it can’t sit on its hands until its approach is adopted across Europe.

“The European Power Tools Association has put forward a proposal for a new European-wide testing standard,” says Owen. “But this will not necessarily be testing to the standards we’ve established with the Off-Highway Plant and Equipment Research Centre (OPERC) for real-life testing, and more importantly, it’s not a test that’s actually up and running yet. We need to deal with the issue now so we’ll use OPERC, but we’ll continue to look at other options.”

It is also aware of suggestions that its communal stance could be interpreted as a cartel, at best anti-competitive, at worst illegal.

“We’re happy to say we require more than is required of manufacturers at the moment,” Owen continues. “If this is more than we’re entitled to under the law, then instead of asking for it as the MCG, we would just ask for it as individual companies – the collective effect would be the same.”

Given the new testing regime is here to stay, the MCG and OPERC are both concerned to reassure manufacturers about its effectiveness.

“Concerns over the comparability/repeatability of the tests should be allayed,” says Edwards. “One manufacturer came for testing of its compaction kit, but the weather was so bad that even the purpose-built test track was not really suitable for testing. But they trusted us enough to say ‘carry on anyway and hopefully the results will be of some use in building the wider picture of vibration levels in a wide variety of conditions’. Of course we also invited them back for more testing when the results could be used in direct comparison with others on the database.”

There have been some problems, however: “Some manufacturers have been happy for as many of their products as possible to be tested, while others either only submit the minimum number – in order to be seen to be complying – or submit products for testing, but then ask us not to show results,” Edwards explains. “You can, if you’re careful, use the results website to deduce those that have complied wholeheartedly with the initiative and those that have been more grudging. You can, for example, look at the number of products on the database for those manufacturers with similar portfolios, or look at the number of tests for which tools have been submitted. After all, a drill is not just used, or tested, for drilling into concrete, but also brickwork, timber, steel...”

HAVTEC explained

The Hand-Arm Vibration Test Centre (HAVTEC) established by OPERC at Loughborough University, was founded to conduct repeatable tests to establish real-life vibration data levels for hand-held tools.

“The link to the MCG came about after we started testing on some Hilti products,” says Edwards. “Hilti asked us to make a presentation, and then asked us if we could test tools and make the data available to it. Once the MCG had come on board, we received tremendous support from Speedy, and then the rest of the hire industry through the Major Hire Companies Group.”

HAVTEC started testing products towards the end of 2005 and the website database was launched in May last year. Its popularity can be determined by the fact it now has more than 6,000 registered users and has received more than 100,000 hits. “We also have more than 600 tool and attachment combinations on the database and are making good progress with breakers, electric drills and power saws, as well as lots of compaction kit coming on board now,” Edwards concludes.

To ban or not to ban...

Although it’s the notion of the MCG banning tools from its sites that has attracted attention, the reality of the MCG’s stance is slightly different. “We didn’t say we wouldn’t allow tools on our sites that have not been tested,” says MCG vibration specialist Mark Owen. “We couldn’t speak on behalf of our 3,000 subcontractors. If they’d just invested €100,000 in kit, it would be wrong to turn around and ban these tools from site.”

Nevertheless, an outright ban is still on the agenda. “At the next MCG meeting we will discuss what’s realistic in terms of a complete ban, based on the average anticipated life of the tools in the system already,” Owen continues.

This delayed introduction is a move supported by the newly formed Major Hire Companies Group (MHCG). “We need people to think realistically about the fact you can’t just cut suppliers off, that you’ve got to work with suppliers, and we can help the MCG with this,” says Asif Latief, Marketing Director for MHCG member company A-Plant. “One high-profile supplier didn’t want its products tested,” he continues. “It turned out this wasn’t because it thought they were bad products, but because it didn’t think they would be tested in a like-for-like fashion.

“Once the situation had been explained a bit more clearly, it was happy to submit products for testing. We also pointed out that the testing means we can help it to meet customer expectations by passing on comments from end-users that come via us into the supply chain.

“We do want independent testing of products and we applaud MCG and OPERC, although we’ve got to be realistic about the timetable. But if a supplier didn’t want to submit to testing, it would end up losing out.”

Paul Howard is a freelance reporter working on the products and materials desk for Contract Journal.

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