KANBrief 2/10
Pedestrian-controlled industrial trucks are in everyday use in many companies. Accidents continue to occur, particularly when this heavy transport machinery is being manoeuvred. 50 percent of all accidents involve injuries to the feet. A newly developed bump strip for foot protection is able to prevent such accidents effectively. Should it prove equally effective in practice, it should be included in the relevant standards.
The German Social Accident Insurance Institution for the trade and distribution industry (BGHW) documents in a database all accidents in the wholesale/warehouse sector which come to its attention owing to mandatory reporting or for other reasons. In order for the most frequent causes of accidents to be tackled effectively, the BGHW has evaluated all reportable accidents from the years 2006, 2007 and 2008 which were classified in the database in association with powered industrial trucks. The accidents were distinguished according to vehicle type (sit-on, stand-on or pedestrian-controlled industrial truck) and accident type, e.g. collision, falling of the load, etc.
Top of the list of accident types by a clear margin and accounting for around 50% are injuries to the operators’ feet. Such accidents typically occur when the rear frame edge of a pedestrian-controlled truck runs over the operator’s feet, for example during manoeuvring in confined spaces. As a result, the foot is trapped or crushed.
Feet inadequately protected
To date, the only known engineered measure for the avoidance of such accidents has been that of lowering the rear frame edge of the pedestrian-controlled industrial truck as far as possible. In accordance with the relevant European standard (EN 1726-1, to become EN ISO 3691-1), the clearance between the floor and the edge of the frame must not exceed 35 mm. The purpose of this form of protection is however primarily that of protecting the feet against the driving wheels, and less so against the frame edge. If the edge is reduced to just a few millimetres above ground level, the risk exists of the vehicle frame grounding or becoming stuck on uneven surfaces such as gate entrances or potholes. It would also be virtually impossible for the trucks to negotiate elevating platforms and ramps.
The maximum permitted clearance of 35 mm thus represents a compromise between accident prevention and practicality. A condition for accident prevention is that the operator must wear safety footwear; this protects the front of the foot. Practical experience shows however that this compromise is frequently not sufficiently effective to prevent injury to the heel and midfoot regions. Employees consequently suffer injuries which result in long periods of absence from work and also considerable cost to the company.
Technical developments for greater safety
A newly developed pneumatic-electrical bump strip for foot protection is effective in preventing such injuries. The bump strip is fitted to the lower frame edge of the pedestrian-controlled industrial truck. When activated, the switch has the same effect as the tiller switch: the truck halts, and may reverse direction a short distance. The pressure-sensitive edge is designed by the manufacturer to be retrofitted at low cost to pedestrian-controlled industrial trucks already in operation. Operators should order the bump strip for foot protection at the same time when purchasing new trucks.
A further measure for preventing pedestriancontrolled industrial trucks from injuring the feet is reduction of the truck’s speed with increasingly steep tiller angle. The closer to the edge of the truck frame operators stand with their feet, the more the truck’s speed is reduced. A solution of this kind is now also available on the market.
Should these two engineered improvements prove effective in practical use, the BGHW will lobby for them to be incorporated into the relevant standards. Evaluation of the frequency and severity of accidents involving pedestrian-controlled industrial trucks shows that manoeuvring or driving in confined spaces results in addition in collision with or crushing of the legs, hands and lower torso region. The number of accidents caused in this way can be reduced above all by organizational measures, such as good training of operators and suitable transport paths which are kept clear.
Dr. Hans-Peter Kany
hp.kany@bghw.de