Executive Hire News › Archives › September 2009 › Executive Report : Safety in the spotlight
Executive Report : Safety in the spotlight
Alan Guthrie reports from Stafford on a recent OPERC conference where numerous Health & Safety issues were discussed.
Given the amount of research into HAV undertaken in recent years by the Off-Highway Plant and Equipment Research Centre (OPERC), it was not unexpected that Health & Safety issues featured prominently amongst topics discussed at the organisation’s recent summer conference, held in Stafford.
Dr David Edwards of Loughborough University, who also founded OPERC, reported on the initial findings from research into mini excavator stability, undertaken at the Centre and commissioned by the contractor Morgan Est. He said that, although Health & Safety Executive (HSE) figures suggested the issue was not a major cause of accidents, anecdotal evidence from operators gave the impression it was an area of concern and that the problem might be under-reported.
Standards of measurement
There was currently, said Dr Edwards, no standard for measuring machine instability, with manufacturers typically undertaking tests using a tilt-table to find the angle at which a machine would become unstable. However, he said that this takes no account of inertia generated when using machines in real-life situations, such as manoeuvring, lifting loads, and tracking across slopes. The research aimed to investigate machine stability in such situations, and the effects of the responsiveness of operator controls, blade operation and tracking. Perhaps predictably, findings suggested that smaller, more powerful models were more likely to tip. They also showed that machines with expanding tracks and smooth controls would be more stable, as were models fitted with a canopy, rather than a cab, as they had a lower centre of gravity. Dr Edwards stressed the importance of selecting machines that were appropriate for particular tasks and the need for operator training.
OPERC is seeking industry support to develop a more sophisticated test rig to assess machines over a far broader range of parameters. It also plans to evaluate zero tail swing models to determine any relative differences in stability.
In an exhibit at the conference, Ammann Equipment promoted its patented VICTAS track system available on models in its ViO mini excavator series. The track rollers have two external guides rather than a single central one, and the track pattern is asymmetrical, moving the reaction point farther towards the outside. This improves stability, particularly when the machine is rotated 90°, and when working on slopes.
Brian Hume, Health & Safety Manager with Balfour Beatty Regional Civil Engineering (BBRCE), spoke about his organisation’s work in addressing visibility issues on forward tipping site dumpers of 6 tonne upwards. He described the possible difficulties drivers had in seeing people and objects in the immediate forward path of the machine, or noticing queuing traffic at road junctions.
Successful trials had been undertaken at three sites over nine months, with dumpers fitted with a vehicle collision avoidance system developed by Spillard Safety Systems. This comprises three ultrasonic sensors fitted low down on the machine to detect obstructions within a 0.5-4m range. If an object is sensed, an audible alarm activates. BBRCE currently has the system fitted to 170 machines at its sites from several hirers, including GAP and A-Plant.
Brian Hume explained that visual confirmation outside the cab would still be essential in certain situations, but the system represented an important safety aid. He added that dialogue was on-going with machine manufacturers to design factory-fitted solutions.
Cut-off saw safety
The issue of ensuring the safe use of cut-off saws was addressed in a presentation by Scott Ellis, Health, Safety & Environment Manager with Morgan Est. Following two on-site accidents, a review of using such tools was undertaken. One incident involved a worker trimming tarmac next to a cast iron gulley. When the blade touched the metal, the machine ‘kicked back’, injuring the user’s legs. In the other accident, an operator was using the tool in an upward direction to saw through 50mm wall plastic pipe, using the top quarter of the abrasive wheel. The machine apparently slipped and flew upwards suddenly, resulting in the operator suffering facial injuries.
Mr Ellis said that, consequently, a prohibition had been put on cutting concrete or asphalt within 150mm of any cast iron street furniture, as well as a ban on using hand-held cut-off saws to cut pipes in similar situations to that in which the earlier incident had occurred. Alternative cutting methods were explored, many of which could be hired, such as special guillotines, pipe bursters, clamped electric saws, and tools resembling large versions of rotating copper pipe cutters used by plumbers. Cut-off saws mounted on wheeled carts or trolleys could also be used for
certain applications.
Also speaking at the conference was Carol Grainger, HSE’s Workplace Transport Programme Manager, who discussed fall protection systems for tail lifts. She quoted statistics concerning tail-lift related injuries that showed 20% were caused by being hit by an object falling from the lift, in 16% of injuries a person fell from the platform, and in 13% someone slipped on the surface. Of the 16% caused by falling, most were from the height of the vehicle bed, which could typically be 2m. Moreover, figures showed that in 66% of cases involving falls from 1-2m, the injury would be described as ‘major’, with the person unlikely to return to work.
A working group had been established comprising end users, manufacturers, industry associations and HSE to develop solutions and user guidance. Key recommendations included incorporating appropriate guardrail protection, operator training, the use of slip-resistant surfaces, and regular cleaning. A technical guide, Preventing Falls and Falling Loads from Tail Lifts, is available through the HSE web site (www.hse.gov.uk). During a discussion session, Mark Turnbull, Safety, Health, Environment and Quality Director for Speedy Hire, commented that the company had been fitting guardrails to tail lifts on delivery vehicles for two years, and that this had proved “an overwhelming success”. •
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