By Euan Youdale09 May 2008
Training and inspection are two key issues when it comes to product and worksite safety. Thomas R Barth of Barth Crane Inspections LLC in the US says accidents often occur because maintenance personnel have not recognised serious faults, or realised how significant they are.
“There should be no slippage of training or inspection. Most accidents, upon investigation, lead primarily back to these issues.”
Barth adds that cranes should be operated smoothly. “Side loading, shock loading, swinging fast and stopping the swing fast can cause metal fatigue, putting undue stress on the pins, chords, lacing, foundation, the whole tower crane. It will be hard for you to know where or when a broken part will show up.”
In addition, years of transporting, erecting and dismantling cause wear and tear, which must be repaired appropriately, Barth explains. “It is crucial that any welding repair is done properly, and inspected thoroughly to prevent collapse.”
Thorough training is the key, Barth says, not only for repair worker and operators, but for those working across the entire work site, including supervisors.
“Ground conditions can appear calm but wind conditions at the jib might not be known by the ground person, giving instruction to the operator.”
Apart from training, on site maintenance workers must be provided with the appropriate tools to carry out crucial work.
Barth adds, “As many site are now, the supers [supervisors] all try to save money and overlook training and the maintenance. These areas are not the place to spare money. Avoiding these areas can cost thousands of dollars and injury or loss of life. It is not worth losing your business over a few thousand dollars for proper training and maintenance.”
Frustrations of a different manner are also being felt in the US over the rated capacity limiter element of the European EN 13000 Standard for mobile cranes. It proposes to replace the existing key that overrides all cut off functions of the limiter with a set up button. This will allow the crane to be rigged and de-rigged but, in operation, no override will be possible. “As such, any misuse of the override key to increase capacities is avoided,• commented the Fédération Européenne de la Manutention (FEM) Cranes and Lifting Equipment product group.
But some crane users, mainly from the US, have opposed the plan prompting European manufacturers to come up with alternatives.
Liebherr has come up with one solution for countries outside the European Union with 75% or 85% load charts. The manufacturer proposes to fit rated capacity limiters with the current features. This would disqualify the crane from receiving a CE-mark. (For more on this story see News)
Another example of how safety regulations can cause problems for crane users is in the UK, where proposed legal requirements for truck side guards have faced criticism from the Freight Transport Association (FTA). The proposals would force all vehicles to comply with existing laws by 1 April, which the FTA said was impractical and prohibitively expensive for many operators.
Although the requirement for vehicles to be fitted with compliant side guards dates back to the early 1980s, explains the FTA, some vehicles, including many with cranes, do not comply fully with the law. In some cases compliant safeguards hamper operator access to crane controls and, in other cases, they cannot physically be fitted. The FTA adds that until now a relaxed attitude was taken by inspection staff.
“At the moment, VOSA [Vehicle and is no secret that the counterfeit parts market causes us a loss of revenue, but concerns impact more than our bottom line. It hits our return on investment for our research and development, it undermines our differentiation strategy and also impacts our reputation as a market leader, says Philippe Cohet, executive vice president for Manitowoc’s crane division in the EMEA.
Last year IC reported how Liebherr had performed extensive tests on counterfeit tower crane sections. The steel was found to be of poor quality, failing to meet the industry’s minimum static strength requirements and making unsuitable for use in cold conditions. “Consequently, there is as much higher risk of material breakages, resulting in a higher risk of the crane overturning and posing great danger to persons and machinery.• (For more on this issue, see the components feature in the September 2007 issue of IC.)
Technology and control
In December 2007 The Construction Plant-hire Association (CPA), based in the UK, published the first edition of its Best Practice Guide on the Safe Use of Top Slew Tower Cranes.
“There are, alas, still too many accidents in our industry. This totally unacceptable situation can only be changed by a combination of training, experience and, above all awareness to risk, of all those involved in the use of tower cranes. Continuing advances in technology help to improve the safe operation of tower cranes but it must never be forgotten that it is effective planning and control of the lifting operation that above all ensures success, said Paul Phillips, chairman of the CPA Tower Crane Interest Group.
The 60-page guide covers the entire lifting operation from the tower crane user’s perspective, paying particular attention to the duties of the whole lifting team, the hazards involved in tower crane operation and precautions to be taken if accidents are to be avoided.
The recommendations include lists of duties that should be completed. At the heart of any lifting operation is the operator and, as part of its recommendations, the CPA sets out a list of their duties.
• Establishing who is in charge of the lifting operation and the other members of the team and their roles
• Establishing which signalling system is to be used and following instructions from only one nominated signaller at a time
• Stopping operations if given any instructions that would take the tower crane outside its permitted duties
• Informing the crane supervisor if any problems arise which would affect the lifting operation
• Carrying out the daily checks and weekly inspections
• Carrying out specified maintenance in accordance with the manufacturers and employer’s instruction and training
• Using the tower crane to lift only the loads that are identified in the lift plan. If the tower crane operator believes that the operation they are being asked to carry out is unsafe, they should initially speak to the crane supervisor or appointed person.
In the event that there is a disagreement between the operator and the crane supervisor or appointed person the operator should notify his employer.