Under American health and safety laws, there is a duty placed upon owners to ensure that their lattice boom cranes meet the national standard ANSI B30.5 Many Americans strongly suspect that few cranes imported into the USA have been tested to this standard. European lattice boom cranes meet their own DIN standards which, while generally recognised as being no better nor worse than the ANSI standards, are different.
It is an issue close to the heart of many Americans. “If we go to other countries we have to meet their codes. But they’re just shipping them in without meeting our codes,” says Vince Morano, president of rental company and lifting contractor Essex Crane. He is still riled by the fact that when invited to tender for a lucrative lifting contract on Portugal’s Vasco da Gama bridge in Lisbon he was unable to meet the strict criteria because his impressive fleet did not meet European codes.
“I resented that,” says Morano. “My feelings are if I’ve got to meet their codes, they’ve got to meet ours. What’s good for the goose is good for the gander.” A key difference between American and European codes concerns boom deflections under side loads. The ANSI code states that a sideload of 2% of the load must not cause the main boom to deflect by more than 2%. (The code does not address jib booms.) Americans would also argue that their whole testing process is much more comprehensive to prove designs. US manufacturers strain gauge every configuration of the boom to verify the stresses of their design calculations.
Mannesmann Dematic of Germany says that all of its cranes sold into the USA have been properly tested to B30.5 and, according to head of design Alexander Knecht, the calculations used by the company put higher side loads to the boom system than the 2% required by ANSI. Mannesmann Dematic has been doing this since 1984 when it sold its first crawler to the USA, a CC 2400 sold to the contractor Kiwit, Knecht says.
Just recently Liebherr has had a US testing organisation to visit its factories to test its LR 1250 and LR 1400/1 machines. The LR 1250 is built in Nenzing, Austria while the LR 1400/1 is made in Ehingen, Germany. These are the only two crawler cranes that Liebherr exports to the USA, according to Friedrich Bär, managing director of Liebherr-Werk Ehingen.
All Test & Inspection of Minnesota, USA tested a pair of LR 1400/1s, in different boom configurations, from 2 November to 11 December 1998. The cranes were certified as meeting the allowable stress and deflection requirements of the codes SAE J987 and ISO 11662-2.
The need to get properly tested has been given impetus not just by the increasing murmurings of discontent in the USA, but also by the establishment of Liebherr Crawler Crane Co in Houston, Texas early last year by Liebherr-Werk Nenzing. This new company is now proud to be able to promote its lift cranes as meeting B30.5. Sales & service manager Kurt Rudigier says that he is aware of the discomfort surrounding the issue.
Liebherr-Werk Nenzing sold its first crane to the USA four years ago and to date has 30 machines in the States, half of which have been sold in the past 12 months. Its product range comprises lift cranes, duty cycle rigs and harbour mobiles. Rudigier says that for the first sales to the USA the customers visited Liebherr’s Nenzing factory to put the cranes through their paces.
The question of meeting ANSI standards is less of an issue for telescopic cranes. B30.5 was written in 1968 and makes no reference to telescopic cranes. Similarly there is no legal standard for duty cycle machines – only for lattice boom lift cranes.
There is, however, an industry standard for telescopic cranes. So while there is no law compelling crane owners to ensure their telescopic cranes meet the industry standard, owners are on weaker ground, warns consultant Howard Shapiro, in the event of legal action following an accident, for example. Cranes meeting the DIN standard, though, or some other internationally recognised criteria, are unlikely to be deemed unsatisfactory by a court.
Bär says that not a single change was needed to the Ehingen-built LR 1400 to get it through its testing. Liebherr’s own engines even had no problem with the strict environmental standards concerning emissions, Bär stresses.
Rudigier says that in testing the Nenzing crane the main difference that Liebherr found between the two codes concerned backward stability: ANSI was tougher. “On our 100t machine we had to add carbody counterweight,” Rudigier says. “It doesn’t improve the load chart but it improves backward stability.” In fact, judging by a comparison of the DIN and ANSI charts of the LR 1250, lifting capacity has been derated slightly for the USA on longer boom lengths.
For example, the imperial ANSI chart for boom lengths between 66ft and 314ft shows that, with 165,350lbs (75t) basic counterweight and 59,600lbs (27t) carbody counterweight, the crane can lift 8,200lbs (3.7t) on 236ft (72.5m) of boom at 200ft (61m) radius.
The metric DIN chart for boom lengths between 20m and 96.2m shows that, with 75t counterweight and just 20t carbody counterweight, the crane lift 4.1t on 72.5m of boom at a radius of 62m. That is an extra 400kg capacity at a further 1m out.
Perhaps this is no big deal, but it is fuel for any Americans who seek to claim that they have the “best and toughest” codes in the world.
