Six axle all terrain crane ranges have been updated across the manufacturers

Manufacturers of wheeled mobile telescopic all terrain type cranes have been updating their ranges of six-axle machines over the last three years.

The 6-axle segment of all terrain crane manufacturers' ranges has far fewer models than the one for five axles - and that is unlikely to change.

A quick check of the major manufacturers' five-axle product lists shows, for example, that Libeherr has 5-axle models and Terex Demag has five. They range from 90 to 220 tonnes capacity and offer anything from a taxi crane at the lower end to high capacity specialist models. As Ulrich Hamme, Liebherr-Werk Ehingen managing director, points out, they have become the "bread and butter" of rental company fleets across the world.

It was not so long ago that 4-axle cranes were the largest general crane in the market, but load weights have increased significantly, pulling up crane lifting capacities with them. The 6-axle ranges, however, according to Hamme and his contemporaries at other major manufacturers, will not expand in a similar way to the 5-axle segment. They hold a unique position servicing the gap up to the heavy lift division of 400 tonnes and above.

Manitowoc launched its six axle 400 tonne capacity Grove GMK6400 and 300 tonne GMK6300L all terrains at April's Bauma 2010 in Germany. They joined the existing GMK6300 and GMK6220L on six axles. According to Neil Hollingshead, Manitowoc global product manager, the new pair is likely to supersede the manufacturer's existing 6-axle machines to become the only models in the range. "The market will decide but I think demand for the 6300 will go down," says Hollingshead.

"The strategy is to have a long boom crane [GMK6300L] that is easy and fast to erect like a taxi crane concept. The long boom can carry out lifts without the need to set up a full luffing jib and you do not have a system like the Mega-Wing Lift," Hollingshead continues. "Then we have a heavy duty crane [GMK6400] that has full luffing jib, and Mega-Wing Lift system to give it more power. We think we cover the market with both of these cranes."

Expanding

The decision to produce two new models in the 6-axle range was not taken lightly. "After a lot of soul searching, speaking to customers and wondering if we could get away with just one machine, we decided we needed the best of the long boom and the best of the heavy lift crane," says Hollingshead.

Liebherr has three 6-axles in its range. The 150 tonne LTM 1150-6.1 falls into the taxi crane category and allows for increased counterweight to be carried.

The remaining two machines are the 250 tonne LTM 1250-6.1 and the LTM 1350-6.1. The latter was launched in 2009 at the Intermat exhibition in France and was a sign of things to come from the industry. "With this crane we took a step away from the smaller bread and butter cranes into the really big telescopic crane," says Hamme.

This, again, is partly demonstrated by the LTM 1350-6.1's luffing jib and Y-guy system - the LTM 1150-6.1 only offers a swingaway jib and the LTM 1250-6.1 has a luffing jib.

"When you compare the 1250 to the 1350, on first sight, they seem to be very similar. With boom lengths of 72 and 70 m, both have 6-axles and a total weight of 72 tonnes on the road. But they are very different concerning load capacity and additional equipment and the cost to the customer. The 250 tonner is very simple, with no Y-guy. The 350 tonner is very sophisticated, has a Y-guy and is much stronger and much more expensive."

Bauma highlight

Terex showed its recently introduced 6-axle AC 350/6 all terrain at Bauma. According to Arndt Jahns, Terex all terrain cranes marketing manager, the 350 tonne capacity machine is an upgrade of the AC 300/6, boasting better performance, especially from long radius at height. "It suits the market better because it has the right boom length and capacity. One of the main features of this crane is the very fast rigging times," comments Jahns. "As well as devices like the fall arrest system for the main boom and patented luffing jib device for easy and safe rigging."

The general consensus is, however, that the 6-axle ranges will not expand in the same way the five axles have. "I think it makes no sense to split the six axle range in too many capacity options," says Jahns.

Consequently, six axle cranes have been designed for flexibility. According to Terex, the AC 350/6, with a total length of 16.7 m, is the smallest 6-axle crane on the market, and the most compact in the 350 tonne all terrain class.

"On one hand, it can be used for work suited to cranes with lifting capacities of under 220 tonnes by using a partial counterweight, which makes it an ideal alternative to medium and large 5-axle units," says a company spokesman.

"It can even be used for operations normally reserved for the 400 tonne class, an area that has traditionally been the domain of much larger machines," adds the spokesman. This can be achieved through the combination of lifting capacity, 60 m telescopic boom length and maximum system length of 125.7 m, says the company.

Tough decisions

Hollingshead confirms the Manitowoc 6-axle range is also unlikely to expand in the immediate future. "With five axle cranes, if you go back a few years, you had a 100 tonner and 200 tonner and we toyed with doing something in the middle, until the market told us we needed it, mainly dictated by axle weight.

"Anything could happen, but the way things are now the six axle is on the limit. We have got a constant improvement policy but I don't see new machines being fitted into the range."

One thing is for sure, the 5- and 6-axle all terrain is a truly global product. "Two and 3-axle cranes are competing with truck cranes, once you get to five axles you are on your own," Hollingshead observes.

South America, Asia, the Middle East are all potential target markets, while some of the lower axle all terrains are predominantly sold in Europe. Jahns agrees. "Luffing jibs start with the six axle crane - we did not have them on five axle cranes. An AC 350 is a typical world crane. We do not produce it in America but America is a huge market for this crane and we have competitors that produce there."

Further ahead

Despite the reluctance to expand the 6-axle stable, there are plans to fill the range further up the capacity scale, at least as far as Liebherr is concerned.

The manufacturing giant has 20 models in the all terrain range, providing a market share of 40%, says Hamme. They will be joined by two further models in the future. While the company wishes to remain silent about one of them it can be revealed the other will be a 9-axle, 750 tonne capacity machine, set for launch in the middle of 2011.

"We have a very successful 500 tonne crane [LTM 1500-8.1] and the LTM 11200-9.1, meaning we have a gap concerning load capacity and cost. Customers all over the world have asked for an additional model between these two, so we started to discuss and design and now we are on the way to introducing this machine," explains Hamme.

The crane is effectively a step up from the LTM 1500 - 8.1, rather than a smaller version of the 1,200 tonne capacity LTM 11200-9.1, and is designed to cater for larger prefabricated modules and other increasingly big loads, in general. "Components are growing - there is a demand for bigger modules." Hamme confirms.