Turning the key24 May 2006
When a German safety body questioned the safety of the load moment indicator's manual override, the European industry banded together to come up with a solution, with surprising results, reports Will Dalrymple
The industry’s new plan proposes that every truck and AT crane will have a new LMI safety system. They will also need to have a data logger – a black box. Although a plan was broadly agreed amongst the industry at Intermat in April, change won't come until the present plan, which is not entirely final, is harmonised across the entire EU - which is expected at the earliest to be 2009. But the change is still radical.
The problem with the manual overrides on load moment indicators started about 18 months ago with EN 13000, the new design standard for crawler cranes, truck and all-terrain cranes. The German regulatory agency, the Berufsgenossenschaft (BGF), did not completely confirm the entire standard – it said the paragraphs about the manual overrides threaten the safety of cranes. And it was not just the Germans who had a problem with it. "Germany, the UK, Belgium, Italy, France, Sweden - they all have the same issue," Gerhard Kaupert, Manitowoc Grove engineering director, told Cranes Today. "The Germans started this, but it is not a German issue."
Faced with this problem, the European manufacturers association, the FEM, formed a working committee within its Cranes and Lifting Equipment section to try to come up with a technical solution. It met with the German health and safety commission (KAN) and the BGF last year and the beginning of this year. It was led by European German crane engineers – Liebherr Ehingen engineer Hans-Dieter Willim, Kaupert from Grove, Klaus Meissner from Terex-Demag, Fritz Pfister from Faun, as well as Marco de Capitani from Italian RT manufacturer Locatelli, among others. The committee met with the BGF, and over a period of about a year developed a draft solution.
During the Intermat show in Paris the FEM working group approved it. "Now it's on the eleventh draft, and it's still a draft," Kaupert said. De Capitani said that a few details remain to be finalised.
The solution is a middle way between the hard line of the safety officials - that there should be no overrides at all - and the users, of which the FEM committee is concerned will not be happy to have the possibility of the override taken from them.
"We are fighting against removing the override switch completely," Kaupert said, which is essential for rigging and emergencies.
The FEM's plan still allows the LMI to be overriden during rigging - when it is outside the duty chart - and also when it is inside the duty chart. But there are some new restrictions. "Overbridging [manually overriding the LMI] has to be made uncomfortable for the driver," Kaupert said.
When the crane is working inside its duty chart, the operator can press a new button to manually override the crane to a maximum of 110% of load capacity. But the crane will only work at a fraction of its normal speed – 15% for electronically-controlled cranes, or 25% for hydraulically-controlled cranes. An emergency switch in the switch cabinet will also bypass the LMI to allow the crane to lower a load in emergencies, or in case a sensor fails, with fewer performance restrictions.
Support from users
While the FEM was working on a technical solution to the problem, the European federation of crane users, ESTA, was beginning to address the issue from another point of view. It was the Dutch crane hire and special transport association, the VVT, that heard about the issue and raised it during the European Special Transport Association's autumn 2005 general meeting in Amsterdam, Lion Verhagen, VVT director told Cranes Today.
At its annual general meeting in April during the Intermat show, the European crane hire and special transport association ESTA members reviewed the FEM draft and broadly endorsed it. "LMIs will not be able to be switched off after 2008," announced ESTA president Christian-Jacques Vernazza at ESTA's awards night dinner during Intermat. "There will be a full security device," he said.
This was a key moment for the resolution of the entire issue, because without the agreement user buy-in, the FEM's potential solution could not progress.
"You must have everybody in the boat," FEM PG Cranes and Lifting Equipment Secretary Klaus Pokorny told Cranes Today.
Having developed a solution, manufacturers were unsure of the customers' reaction. Some manufacturers were doubtful that crane rental companies would be happy to do without LMI overrides, because the practice is so common.
"It's just what you have in the case of speed limits," Locatelli engineer Marco de Capitani told Cranes Today. "If a driver can override a crane, you can be sure that he will."
"I was worried," Kaupert of Grove said. "I was astonished that the customers agreed."
For at least one end user who was involved, the decision was a simple one. "Changes in the override key will make the cranes safer," Steve Cooke, Ainscough crane hire engineering director, told Cranes Today during the ESTA awards dinner.
"There are problems with contractors in Europe," Cooke said. "Lots of companies who are provided a crane are pressurising crane operators to overlift. They tell our operators, 'We did a 40t lift with this crane, and it was fine' or 'You're not as good as the last crane operator.' This change encourages safety and ensures that we provide the end user with the right capacity crane in the first place."
Lion Verhagen of the VVT put it another way: "The issue is that operators know about the [manual override] switch, and there is pressure" from contractors, he says. They must decide whether to lift within the crane's load chart, or to flip the switch and override the crane's safety system. "In the future they can't make a decision."
"It is a significant change to the whole industry," Cooke said. "We are trying to encourage everyone to be safer."
Although ESTA came out in favour of the proposal, it was clear that European crane rental opinion on the issue was far from unanimous.
The federation's newest member, the Swedish crane association, welcomed for the first time at the Intermat awards dinner, was one. "ESTA says that we should remove the switch, but we need it. The Swedish crane hire association is against taking it away," said its secretary Lars Morast. "ESTA thinks we have to, because customers override the crane's safety devices."
Cooke acknowledged that not everybody was in favour of the idea, but maintained that it was the best thing for everyone, in spite of their opinions.
"It's a democracy," he said. "If you take a democratic approach, you talk to members and discuss the issues raised and represent what they say."
"There may be companies that don't want to move, that abuse a crane, override it and overlift. But if a majority of members want to support it, that's different.
"Smaller crane companies in all fairness don't want to do anything to make a change that would mean that they have to make a difficult decision. People like Christian-Jacques Vernazza [of Mediaco], Roderick Van Seumeren [of Mammoet] and Martin Ainscough make it possible to drive forward these safety changes. It's not a personal vendetta."
There are two major technical changes that the manufacturers will have to make to comply with the FEM plan. First, hydraulic cranes will need re-engineering. "It's a lot of work for us. Hydraulic cranes are difficult to reduce the speed of motion," Kaupert says. "You have to make a special valve with larger hardware," he said. Electronically-controlled cranes will be simpler to adapt. Because their control systems are computer-controlled, a simple software change will make them compliant.
However the crane is controlled, however, it is going to need a data logger that will record the periods when the crane is being overriden. According to Steve Cooke, the data logger will record many different parameters from tens of sensors on the crane, ranging from boom angle, hours of operation, to fuel consumption and more.
Cooke says that data loggers are a good thing for Ainscough, and a good thing for its crane operators. "We have 270 cranes with data loggers fitted. We make sure that the driver is aware of the logger. There was a recent situation when there was a problem with a crane, and our customer was saying that he provided clear instructions and was not his fault. We took information from the device, and the logger supported the driver," he said. In the event of an incident, the HSE takes information from the data logger, Cooke says.
Nothing is likely to change until 1 January 2009, the date the manufacturers have agreed to implement the new system on all their new models of truck, AT and crawler cranes. Because of the alterations required to make the system work, pre-2009 cranes will not be retrofitted with the new safety system. By then, the change is expected to have made it through the harmonisation process and to have become law in the EU. "We are very optimistic that the EN 13000 will be amended very soon and match the essential requirements of the Machinery Directive, but it is never a predictable process," Pokorny said.