黑洞社区

When Rok鈥檚 Aly Miller walked onto the construction site of a new hospital wing in the north of Scotland, he witnessed a scene that made him reconsider his work as a safety coach. He was engulfed by plumes of dust from a hand-held saw operated by a joiner sawing MDF panels. Straining to see through the cloud, Miller noticed that while the joiner and his colleagues wore the appropriate protective goggles and masks, the nearby electricians and plumbers wore no facial protection and were freely breathing in the toxic particles.

鈥楢lthough shocking to witness, this situation is typical of many sites across the UK,鈥� complains Miller. 鈥業t made me realise that these problems could have been avoided if the dust was removed by the saw itself at source, rather than having to manage its effects. There are several features tool manufacturers should be implementing to improve safety on sites.鈥�

Miller isn鈥檛 alone in believing that tool manufacturers are failing to meet the demands of construction鈥檚 end users. Other contractors complain about dust and sparks, as well as the safety risks caused by high-voltage cables that snake across sites. Although manufacturers are now producing cable-free, battery-operated alternatives, these are considered heavy and lacking in power. Meanwhile, theft remains a problem as tools lack built-in security and are easily stolen.

On the other hand, manufacturers claim their tools address many of these concerns and are designed in direct response to feedback from end users and site managers. 鈥楾he end user is instrumental to all of our products, this week we鈥檝e got two R&D guys coming over from Japan purely to speak with users on sites and health and safety managers,鈥� comments Andrew Helby, head of marketing at Makita.

But there鈥檚 a third point of view: that of the operatives using the tools on site. The latest innovations might be designed to help contractors meet health and safety legislation and productivity targets, but what are the pros and cons for the skilled workers that use them?

CM visited the Angel 黑洞社区 in north London, where BAM Construct is building an office and retail development for Derwent Valley, armed with some of the latest power tools from Bosch and Makita. Workers with groundwork subcontractor Getjar use skill saws to cut formwork, angle grinders to slice rebar and rotary hammers to break up concrete and drill holes into an existing concrete frame.

After some tests with the new tools (see below), Ianluka Matei and Daniel Budau voiced complaints that battery-operated skill saws and angle grinders didn鈥檛 deliver enough power, while a Bosch skill saw was criticised for handling difficulties due to the position of the blade. But perhaps part of the problem was the nature of the test itself. 鈥榃e found it difficult using new tools because you get so attached to your old ones. We鈥檝e become attached to Makita because they鈥檙e robust and last a long time,鈥� says Budau.

Most site managers will be aware of the problems of noise, dust and vibration generated by machinery. 鈥楧ust is a particular problem when cutting concrete blocks, and with joiners using bench saws and planers,鈥� says Rok鈥檚 Miller. 鈥楽ome machines can be hooked up to an external extraction system on site, but many sites don鈥檛 have these, and in practical terms, using equipment that鈥檚 supposed to be portable, it really needs to be an integral part of the tool.鈥�

Makita says its woodworking machines are available with built-in extraction, but its angle grinders and rotary hammers need an attachment. 鈥榃e鈥檝e come under pressure from health and safety managers to include extraction, but market take-up for this type of feature is very slow,鈥� responds Helby. Bosch also has a limited offering, including the GBH223 rotary hammer, which has a removable extraction unit.

Spark capture is another area where site managers would like to see more development. Robert Campbell, group safety manager for Scotland at Rok, says: 鈥業 haven鈥檛 seen much effort going into modifications to capture sparks from angle grinders and skill saws. We do a lot of work with the petrochemical industry, and although there are precautions in place to control the environment, integrated capture is needed in tools.鈥�

The manufacturers, however, point to improvements. Makita鈥檚 LC1230 circular saw incorporates a tungsten carbide blade that significantly reduces spark emissions, although none of its products integrate guards that prevent sparks entirely. From the end of this year, most Bosch hand-held saws will incorporate a second guard to fully conceal blades, but it is not considering integrated extraction.

Meanwhile, managers are welcoming the switch to lower voltage battery-powered hand-held technology, which eliminates the need for high-voltage cables. Battery performance has improved significantly in recent years. Developments in lithium ion technology have cut charge times 鈥� from an hour to just 20 minutes in the last three years 鈥� and usage periods have increased, as have the number of charge cycles per battery.

鈥楲ithium ion batteries are the way forward. They make for lighter tools, which means less vibration and easier control,鈥� says Martin Sibley, product manager at Bosch. 鈥極ur latest tools include a burn-out control, which means that if put under stress, the tool turns itself off before motor or battery burns out.鈥�

On the BAM site at Angel, Martin O鈥橞rien, site manager at BAM, is encouraging the use of cordless products. Ianluka Matei tried out the cordless Bosch GKS 36 V-LI Professional circular saw, using it to cut sheets of ply and lumps of timber to create formwork.

鈥業 found it less cumbersome than a corded saw when working at height,鈥� he reports 鈥業t also came in handy when I was a long way from the power point as cable voltage drops considerably the further away you are,鈥� he said. 鈥楤ut the power was generally low compared to the corded saws and it struggled to cut through several sheets of ply at once.鈥�

But Bosch鈥檚 Sibley says many cordless tools are starting to match the performance of their corded equivalents. 鈥榃e have a 36-volt battery drill that can deliver the same force as a 600-volt impact drill,鈥� he says. Such power savings are proving attractive to the eco-conscious 鈥� Makita鈥檚 Helby says the use of lower-power cordless devices was a part of the sustainability strategy for the 2012 Olympics.

Contractors using multiple cordless tools might consider installing battery banks 鈥� lockers incorporating chargers hard-wired to the mains 鈥� which ensure tools and chargers are secure and not left lying around on site. 鈥榃e use them when we start dry lining and fitting out,鈥� says James Carpenter, a construction manager at Kier Build. 鈥楾hey keep the place tidy and you don鈥檛 get people continually looking for spare plug points.鈥�

Another issue identified by Rok safety coach Miller is the frequent lack of 鈥榝ail safe鈥� functions on hand-held tools, which means they can still be used in an unsafe condition. 鈥極ne of our plumbers was injured by a crimping tool with a locking device that didn鈥檛 fail safe. Tools should have a mechanism similar to the old nail guns that required positive pressure before they would activate,鈥� he says.

It鈥檚 a disturbing fact that theft of equipment from construction sites is on the rise and hand-held tools are a particular target. 鈥榃e get small power tools stolen all the time, anything that could be used for home DIY,鈥� says Paul Corner, site manager at Morrison Construction. 鈥榃e usually have a person assigned to look after each tool, and on larger sites they鈥檙e locked away each night, but manufacturers should make tools more traceable.鈥�

A glance at manufacturers鈥� catalogues reveals little progress in this area. Makita has no 鈥榓nti-theft鈥� devices incorporated into its tools, but is currently exploring the use of swipe cards that allow only authorised users to activate tools. Bosch is also looking at key fob locking systems, similar to those used on cars, as well as integrating tracking devices into tools.

But even this technology could prove impractical on construction sites, where it鈥檚 normal for several workers to use the same tool. 鈥楽ecurity access may be a step too far, it鈥檚 hard enough finding your car keys, let alone this,鈥� says James Carpenter. 鈥業f a card holder鈥檚 off-site or sick, other users will be stuck. It鈥檚 also quite common for a chippie to have five or more tools, a jig saw, drills, a planer etc, so lots of cards or security keys would be impractical.鈥�

Despite the concerns voiced here, manufacturers are pushing forward with innovations.

In the near future, users can expect increased efficiency and reduced vibration from hand-held tools, allowing longer periods of use. Batteries will be reduced in size, improving weight and handling, while power and longevity will increase.

But input from all areas of the industry is required to ensure their suitability for construction. 鈥楾he HSE and contractors need to put more pressure on manufacturers to make improvements,鈥� says Rok鈥檚 Campbell. 鈥業鈥檝e visited a European factory to try and influence design decisions, but haven鈥檛 seen the ideas make it into the tools,鈥� he concludes. cm