There is a trend for high capacity rough terrain cranes but the mid-range remains popular

There is a trend for high capacity rough terrains but the mid-range remains the most popular. The crane type is also breaking out of the North American market to become a more global product. Euan Youdale reports

In addition to demand for increasingly high capacity rough terrains, manufacturers are also concentrating on lower capacities where the scale of production is highest.

Tadano is launching four new rough terrain models, each with the longest boom in their capacity class, says the manufacturer. The GR-800EX, GR-600EX, GR-500EX and GR-300EX, with 80, 60, 50 and 30 tonne lifting capacities, respectively are aimed at the general export market. For North America the four machines are designated: GR-1000XL, GR-750XL, GR-550XL and GR-350XL.

Telescopic boom lengths are from 12 to 47 metres for the biggest GR-800EX model and reduce to 9.7 to 31 m for the smallest GR-300EX. Jib lengths range from 10.1 to 17.7 m at the top end of the range to 7.2 to 12.8 at the bottom. All except the GR-300EX have a rounded profile to the boom, which is made of lightweight and high strength high tensile steel, says the manufacturer.

In consideration of the environment, the new Tadano models include a fuel monitoring system and eco-mode system to reduce fuel consumption by restricting hydraulic pump displacement while the engine idles. This is already available for customers in Japan.

The AML monitoring system offers improved operation and visibility and the automatic moment limiter (AML), displaces the emergency release function. It also controls the asymmetric outrigger extension to maximise performance for each width. It is the first in the market for this system, says the manufacturer.

Manitowoc's most recent RT products are the Grove RT9150E and Grove RT765E-2. With a 135 tonne capacity, the RT9150E is the highest capacity rough terrain crane in the Grove line. In addition, the 60 m main boom is the longest on any current production rough terrain crane, says the manufacturer, which means it can reach places that previously required a jib.

With a jib and insert, the crane achieves a maximum tip height of 95 m. Working with its full standard counterweight of 17,690 kg the crane has a lift advantage nearly 60% greater than the next model in the line.

Another interesting Grove machine in the sector is the RT9150E, an RT hybrid. It combines the upper works of a Grove GMK5165-2 all terrain crane (GMK5130-2 outside the USA), and the lower works of the 120 tonne capacity RT9130E rough terrain. The result is a high-capacity crane that mounts to a compact and durable carrier, says the manufacturer.

USA Zoomlion distributor Global is introducing four models: the RT35, RT55, RT75 and RT100. In each the model number represents their metric tonne capacity. The RT55 is the first to go into full production in January. Next will be the RT75 and, by mid-year, all four models will be available, says Ed Gibson, Global national sales manager.

"RT cranes come fully loaded with everything from the offsettable jib and auxiliary winch, to the items that seem smaller, like air conditioning and seat tilt. Each is something the customer wants in their crane and we offer them all standard," explains Gibson. They include Tier III-compliant Cummins diesel engines, Dana transmissions and Greer electronics. In addition, they are ANSI and CE certified, adds Gibson.

The RT crane was born in North America, while other regions accomplished lift tasks without them, using instead, for example, in Asia the truck crane and in Europe the all terrain.

"When people in these countries started really looking at the capacity, capability and cost-per-lift equation of these cranes, they started seeing the benefits of using RTs over other types of technologies, says Ingo Schiller, Manitowoc senior vice president of global marketing, "But the fact that we don't have to spend the resources to make these cranes road legal, also means that for similar capacity cranes, the cost-per-lift is much lower with an RT."

Another example comes from South America, "In Brazil, we estimate we have had 18 to 20% growth in the last 12 months. RTs have not been used that much in the last 10 years; now they are becoming more and more popular because of the long-term projects we have going," says Rene Porta, crane manager in Brazil for Chinese manufacturer Sany.

T Murakami, general manager at Tadano marketing in Japan, says its new models will be suited to energy-related applications, among others, in North America, the Middle East and Russia, plus mining in South America, Australia, South Africa and Russia. "Furthermore, for Russia in particular, our product development is underway to enable machines provided with resistant structures and equipment to operate at -40 degrees centigrade."

Rick Curnutte at US manufacturer Link-Belt says much is changing in the North American market under OSHA (Occupational Safety and Health Administration) regulations and engine emission rules. Cranes manufactured after 8 November 2011 must conform to outrigger position sensing and drum rotation direction rules, among others.

Link-Belt's Tier 4i/Euro Stage IIIB emission compliant engines will have a diesel particulate filter (DPF). It captures soot when the engine is not operating at its peak efficiency. To remove this soot, the operator may be required to perform a manual DPF regeneration if the engine does not perform it automatically. "We'll be adding a display in the cab to clearly explain what is happening with DPF regeneration and what action, if any, the operator needs to take. Our main goal is keep an RT simple and easy to operate," says Curnutte.

At the same time, high capacity RTs are increasingly popular. "We've seen this in industrial and energy applications where the modular design of components warrants heavy lifts and the RT, with its rubber tyres and high manoeuvrability, is particularly well suited," comments Curnutte.

Gibson confirms the trend, "We are seeing 150 ton RTs. And we are interested in those higher capacity models simply because we recognise there is a market for larger cranes, and that market is growing."

At Manitowoc, Schiller explains, "By investing in a high capacity rough terrain, customers can get all the lift capacity of other types of cranes without the additional cost incurred by investing in a road-legal crane. Also, these higher capacity RTs can squeeze into areas on job sites that other types of crane could not."

Expanding on the rough terrain and all terrain cross-pollination, he adds, "using an AT upper works and mounting it to a rough terrain chassis, gives users the best of both world in terms of capacity and ruggedness."

In future, while the lower 30 to 80 tonne capacity machines remain the core market, the biggest machines will continue to increase in popularity and capacity, according to Gibson. "Along with that, they will be getting lighter and easier to transport, that is going to be key as the capacities continue to increase. Those two have to go hand-in-hand."

Schiller cautions, "There technically is not a limit to size, but there is a point where it becomes impractical. If you make them too large, you have to spend too much time and effort to assemble and disassemble to transport them between jobs. There just becomes a point of diminishing returns."

Schiller adds, "We will continue to see the marrying of AT and RT technology. The sophistication and strength of the AT and the rugged mobility of an RT is a very appealing combination to many customers."