by tomboland » Tue Sep 09, 2008 10:08 pm
The issue of lifting persons in baskets suspended from cranes has been a hot topic for several years.
There is a strong body of thought that argues that cranes are designed for lifting goods and not people and therefore is contrary to the EU Use of Work Equipment Directive 95/63/CE 1995.
When crane Hire Company NMT offered rides in a basket suspended from a crane to visitors to the 2002 SED show, the International Powered Access Federation swiftly called in the Health & Safety Executive. After some discussion, the authorities put a stop to the rides (which, it should be added, were merely to raise funds for charity).
The basis for stopping NMT was that it was deemed to be using the crane and basket as a fairground ride rather than as industrial equipment .It is, in fact, perfectly legal in the UK to ride in a man-basket suspended from a crane, although some crane owners feel that clearer guidance is required from the HSE. The HSE says that its attitude to riding in baskets suspended from cranes is very similar to its attitude to the use of work platforms attached to forklifts. In each case, LOLER says that it may be done only in " exceptional circumstances”. In effect, this means where a risk assessment has demonstrated that there is not a more appropriate, safer alternative readily available. This is also in line with the Work at Height Regulations' hierarchy of risk. There is also a requirement that the basket is designed for the purpose, firm guidance on the design and use of man-baskets suspended from cranes comes with the publication of EN 14502-1 Cranes – Equipment for lifting persons - Part 1: Suspended Baskets. This European Standard was approved by CEN on 25 May 2005and will be published by BSI within the next few weeks. The new standard has not been mandated under the Machinery Directive, which means that it takes the form of guidance rather than a legally binding document. However, anyone facing a law suit will be in a weak position if they have not adhered to published best practice,
Which the standard represents. Nor does the standard take precedence over national laws governing the use of man-baskets on cranes (France, for example, takes a much stronger line than the UK against the practice). Among the demands of EN 14502-1for the design of baskets are the following key points: Suspended baskets shall be incombustible and protected against corrosion. The basket shall have a minimum freestanding height of two metres. When the suspended basket is designed to be used in situations where falling objects may be a hazard, the basket shall have a roof, able to withstand the impact of a steel ball weighing 7kg, falling from a height of two metres. When calculating the rated capacity, the weight of each person shall betaken as at least 80kg plus at least40kg of equipment for each person .A safety factor of at least two must be used in design calculations. The basket must be attached to the crane hook with either steel wire rope slings according to EN 13414-1or chains according to EN 818-4with a safety factor of at least: eight for chains, and 10 for wire ropes, including the end termination. The slings shall be fitted to the basket in such a way that they can only be removed with tools. The vertical distance between the floor of the basket and the crane hook shall be no more that three metres. The floor of the basket shall be secured to the frame by welding or some other equally effective means. The floor must be slip resistant and have drainage.
Free space on the floor shall be at least 600mm x 600mm for one person, and at least 400mm x 400mm more for each additional person. Suspended baskets must be designed so that if a load 1.5 times the rated capacity is applied at the worst position on the floor, any resulting inclination shall not exceed 20°.
Any gate shall not open outwards and shall have an automatic catch to prevent it from being opened inadvertently. Baskets shall have anchorage points in accordance with EN 795 for personal protective equipment and people in the basket shall wear a harness with lanyard. The standard also sets out detailed requirements for handrails and contents of the instruction manual.
The manual must state that the suspended basket shall only be used in combination with cranes, which are designed for the lifting of persons. The only clue as to which cranes are considered" designed for the lifting of persons" comes with the proviso that cranes must have powered lowering and not free-fall winches.
The manual must also state that: The crane and the suspended basket shall only be operated by people trained in the safe use of the combination, including the operating procedures for egress in case of power supply failure or control failure.
A crane driver should always be present at the normal crane control station when the basket is occupied.
Visible and audible communication should exist between the persons in the basket and the crane driver at all times during the lifting operation. The required equipment necessary to perform an emergency rescue shall be available throughout the lifting operation. During operation the employer should not require the crane driver and signaller to do other work at the same time, or direct a second crane and/or Basket.
Lifting slings for suspended baskets should not be used for any other purpose. Suspended baskets should not be used in wind in excess of 7m/s (25km/h), electric storms, ice, snow, fog, sleet, or other adverse weather conditions that could affect the safety of personnel. Machines, which can be operated simultaneously in the same place with risks of collision, should be stopped. Unintended movement of the basket should, where possible, be prevented e.g. by means of guide ropes or anchoring.
The suspended baskets, hook, catch, and fixed load lifting attachment should be inspected prior to each use. The hook must have a safety catch .The basket shall be positioned on a firm surface when entering or exiting. The lifting and supporting should be made under controlled conditions and under the direction of one appointed person.