The industry now has a range of tried and tested solutions to help measure and reduce damage caused by hand arm vibration. Report by Margo Cole.
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Historically, health problems associated with hand arm vibration have been one of the biggest causes of disability and injury claims in the construction industry. Too much exposure to vibration from equipment like jack hammers, concrete breakers and disc cutters can cause a range of painful and disabling disorders of the blood vessels, nerves, joints and tendons in the hands and arms, the most well-known of which is Vibration White Finger (VWF).
The Health & Safety Executive (HSE) estimates that there may be as many as 300,000 people in the UK with VWF, and working with construction equipment is one of the biggest causes. The good news is awareness of the problem is now high, and new cases are at an all time low.
This may be due to the frightening cost of compensation claims, following successful legal action taken against employers by miners, as well as the introduction of legislation in 2005 in the form of the Control of Vibration at Work Regulations.
These require employers to assess employees’ VWF risk, decide whether they are likely to be exposed above acceptable daily levels and, if they are, introduce controls to eliminate risk or reduce exposure. As a result, many plant companies have modified their equipment to reduce the vibration they generate. But some equipment will always produce vibration, so the challenge is to ensure operatives do not over-use it.
Many plant companies have modified their equipment to reduce the vibration they generate. But some equipment will always produce vibration, so the challenge is to ensure operatives do not over-use it.
The legislation stipulates how much vibration is acceptable in the form of exposure action values (EAVs) − the daily amount of vibration exposure above which employers are required to take action. It also sets exposure limit values (ELVs), the maximum amount of vibration anyone can safely be exposed to on a single day. HSE tables show how to calculate whether someone is close to either of these levels, using a combination of the vibration rating of the tool and the number of hours they use it.
In the past, this has involved site workers filling in paperwork at the end of every day, saying how many hours they spent on different tools. But operatives often swap between different pieces of equipment and may not remember how long they were using each. And, at the end of the day, when the calculations are done, operatives may have exceeded their safe limit.
Increasingly, contractors are turning to devices that automate some or all of this process. At one end of the spectrum is HAVi, a low cost hand arm vibration indicator that comes fixed to a tool and pre-programmed with the vibration rating for that tool.
Whenever the tool is in use, it will automatically calculate the vibration exposure of the operative using it. When the operative stops, they simply record the number of points they’ve accrued and add them to any they may have already collected that day.
Modifying working patterns
The big advantage is that operatives can see their totals, and start to modify their working patterns once they learn which tools rack up vibration the fastest. Their supervisors or health and safety managers can also see which operatives are subject to the highest levels of exposure, and reorganise workload if necessary.
A far more sophisticated level of analysis comes from Reactec’s HAVmeter, which totally eliminates the need for paper-based data collection, so operators can see what their exposure levels whenever they want to.
The system, launched last year (NCE 22 April 2008), consists of three main components: a tool tag permanently attached to the tool and coloured green, amber or red, depending on the tool’s vibration; the operative’s HAVmeter, attached magnetically to the tool tag; and a base station, where the HAVmeter is docked, and all the information downloaded.
As operatives move from one piece of equipment to another they take their meter with them, attaching it to each tool tag as they go. It displays a cumulative total.
The HAVmeter automatically records vibration exposure, and as operatives move from one piece of equipment to another they take their meter with them, attaching it to each tool tag as they go. It displays a cumulative total, so operatives can see what their exposure level is. Amber and red warning lights alert the operative when they reach the HSE’s exposure action and limit values.
At the end of a shift the operative docks the HAVmeter in a base station, and the exposure information it has recorded is automatically downloaded and can be used to compile reports for individual workers, gangs, departments or regions.
Both the HAVi and the HAVmeter have been adopted by the industry. Morrison Construction has over 100 HAVi units on sites across Scotland, while Bam Nuttall recently trialled it for three months on a waste water treatment project in Kent. “What the HAVi did immediately was get operators on board; they could understand how it worked and what it was measuring,” says Bam Nuttall site agent Nick Howard. Using the system helped operatives realise how some tools they thought of as low risk could have a major HAV risk if they were used for a long time.
Meanwhile Reactec boasts over 100 companies using the HAVmeter, including Amey, Carillion, Costain, Laing O’Rourke and May Gurney. Hire companies Speedy and Gap have also signed up to supply tools with the tags already fitted.
Seeing the benefits
The Interlink M74 Joint Venture between Balfour Beatty, Morgan Est, Sir Robert McAlpine and Morrison Construction is using the system on the massive £445M contract to build the final section of the M74 motorway in Scotland.
Derek Chambers, director of corporate and social responsibility at Interlink, says: “We have made a major investment in the kit and are now seeing the benefits of upfront information on exposure to the workforce, from the indicator lights and “on screen” display on the HAVmeter, and accurate records of daily exposures captured when the HAVmeters download their data to the base station. The data provided is also a valuable source of information to our site based occupational health provider.”
“Our operatives like the system as it gives them real time information − it is much more user friendly than any paper based system.”
Dave Atkinson, Severfield-Reeve
Structural steelwork fabricator Severfield Rowen, which includes Severfield-Reeve and Watson Steel, has also invested in the HAVmeter system, trialling it for four months on one site before rolling it out across the group in August 2008. More than 350 operatives now use it.
“Our operatives like the system as it is easy to use and it gives them real time information about their own vibration exposure − it is much more user friendly than any paper based system,” says Severfield-Reeve health and safety manager Dave Atkinson.
“The information collected and the clear display of this exposure data in the software enables us to refine working practices and risk assessments based on accurate tool usage and vibration exposure records.
It also gives us key performance indicators, allowing us to set clear targets in our efforts to reduce exposure to HAVs.” The uptake of both devices indicates that the industry is keen to improve its knowledge about vibration risk, and minimise effects on workers.