Rough and Ready

The rough terrain (RT) segment offers users a range of features and capacity classes which makes them suitable for medium and long term projects in sectors as diverse as energy, civil engineering, and general construction. While their lack of roadability makes them an unlikely choice for simple short term jobs on any site an all terrain can access it also means that crane designers do not have to be quite as precise in optimising the cranes’ capacity and axle loading.

That combination of widespread use on long term sites and design flexibility makes them a strong candidate for early electrification. Crane designers can assume that many sites will be able to provision electric power, allowing for recharging. And they may be able to more easily accommodate the change in weight and dimensions of power components than they could on an all terrain.

At ConExpo this month we should expect more news from Tadano on the launch of the first crane in the segment to be electrically powered. The company has been reluctant to describe the crane in detail ahead of the Las Vegas show but has said the crane will be able to drive to the jobsite and complete all lifting operations using battery-electric, rather than diesel, power.

Cranes like this will become increasingly important as local planning authorities implement restrictions on emissions in urban areas. Many cities around the world have already begun to take steps in this direction, with low emission zones already in place in some cities, and the first zero emissions zones under trial.

Over the next decade project owners will look to achieve their own net zero goals in their operations and on construction sites. The greenhouse gas protocols many companies use to measure their sustainability goals consists of three ‘scopes’. Scope 1 of the protocols measures emissions generated within a company, through burning diesel in its own vehicles, or producing emissions as a result of its own activities. Scope 2 considers emissions from energy use; for example, does the electricity it buys on the wholesale market come from gas, wind, or nuclear? And Scope 3 includes emissions from across the company’s entire supply chain. This last would include emissions from equipment used to construct new facilities for the company itself, or its suppliers.

This will further push adoption of electric equipment on many sites. So too will noise regulations. On many city sites operations cannot be carried out at night or the early morning due to noise. Tadano says that its new crane will emit lower noise when operating. This will result in significant advantages for customers, the company says, when working in congested urban areas with noise ordinances, completing lift projects at night, and operating indoors.

The details of the new crane are still firmly under wraps, at least until ConExpo. But it would perhaps be a reasonable guess that this crane will be somewhere around the 100t class, with a long boom, as this has been the focus of many recent crane launches.

ALL PURPOSE FOCUS

The 100t class was the focus for Liebherr when it first re-entered the rough terrain market a few years ago after a decades-long absence. It’s perhaps the class that is most widely demanded by users and the direction of travel looks to be very much towards higher capacities and longer booms on two-axles.

Ehingen’s first two new models offered capacities of 90t and 110t. At ConExpo, it will be launching a new 130t model: the LRT 1130-2.1. This crane will be, the company says, the largest on two axles. The capacities of Link-Belt and Manitowoc Grove’s two-axles RTs, for example, both top out at 120t, with booms of 50m on the Kentucky-built 120|RT, and 60m on Manitowoc’s GRT8120.

The new Liebherr will add 10t of capacity, compared to both these cranes, and feature a 60m long boom. This boom length is now very much the norm for telescopic cranes and looks likely to be a target for most new launches in the rough terrain class.

The six-section Telematik fast-extending boom can be supplemented with a 10.8m single folding jib or a 10.8–19m double folding jib. It is mounted at angles of 0°, 20° or 40°, or can optionally be hydraulically tilted from 0° to 40°. With an additional sevenmetre lattice section as a telescopic extension, the new crane reaches hook heights of up to 85m.

The crane was first shown in prototype at Bauma in October 2022. It will receive its official launch at ConExpo, and Liebherr says its primary focus will be the US market. Here, long journeys between sites, on roads with often highly variable vehicle weight and axle loading regulations, tilts the balance further in favour of the use of RTs over ATs, even for shorter jobs. And US users make heavy use of these cranes in pick and carry and tilt-up operations.

But the crane has also been designed to be sold internationally. It can be transported economically on low-loaders worldwide. Its width is 3.4m, its height 3.85m and its chassis length 9.4m. The transport weight is 48t without ballast, but with the folding jib and hook block. This can be reduced further to 44.8t.

All of Liebherr’s rough terrain cranes comply with a global, uniform safety standard and thus with globally valid regulations such as the US ASME B30.5 standard, the European EN 13000 standard, the Australian Standards (AS) and the Russian GOST standard. Safety features on this crane include automatic monitoring of whether the crane is working on outriggers or on tyres. Combined with the company’s VarioBase stepless outrigger system, this allows the crane to work to its maximum available safe capacity, however it is set up.

In Munich, as Liebherr showed off the prototype of this new 130t crane, Manitowoc — which is not taking part in ConExpo — launched its upgraded 100t model: the GRT8100-1. Like the Liebherr, this crane also brings in new flexibility in crane set up. The new crane makes use of Manitowoc’s MAXbase system, adding the ability to work from variably positioned outriggers.

Much of the design of the two-axle, 100t, 47m main boom machine is taken from its bigger counterpart: the 120t GRT8120. The cranes share a similar chassis. The new machine also updates the engine and transmission of its predecessor, improving fuel efficiency and so reducing both cost and emissions.

“The GRT8100 has been a popular choice with customers worldwide. With the GRT8100- 1, we have taken a great crane and made it even better,” said Federico Lovera, product manager for rough-terrain, industrial, and lattice boom crawler cranes at Manitowoc. “The new Grove GRT8100-1 will go into production at our U.S. and Italian factories simultaneously, allowing deliveries to customers around the world to begin in early Q2 next year.”

INTERNATIONAL AND DIVERSE

But not every new crane is in this 90–130t high capacity class. Rough terrains are used around the world often on jobs that require much less lifting power, such as general construction. These machines are also often used on long term contracts in sites, like refineries, where their off-road mobility and pick and carry capacities makes them ideal for ongoing maintenance.

Tadano’s latest entry in its CREVO, or Crane Evolution, series is aimed solely at its local, Japanese, domestic market.

The new N061-RG, with a capacity of just 16t and a boom length of 28m, is a very different machine from larger globallyfocussed machines. Where it excels is in manoeuvrability. With Japanese developers working in crowded cities, and often trying to make us of as much space as available on expensive ground, compact cranes are key.

The new crane measures just 8.3m long x 2.2m wide, with a height of 3.15m. On this relatively compact base, with a tight turning circle, it still has a boom that's 50cm longer than that on preceding models.

It features systems to adjust engine speed to the demands of lifting, increasing power automatically when the crane lever is used, just as much as is needed.

When the crane is idling, the power take off pump stops automatically, further reducing fuel consumption, noise, and emissions. The new crane also features an upgraded engine, in line with the latest emissions standards, and a range of modern cab and remote-control options.

When Terex sold off many of its crane ranges, it retained facilities manufacturing cranes in two key classes: tower cranes, and rough terrain cranes. These latter join the company’s class-defining Franna articulated cranes, a crane type once rarely seen outside of Australia, but now being sold in markets such as India, under the umbrella of the company’s minerals processing division.

When the sale to Tadano of its all terrain and crawler crane ranges, built in the former Demag factory in Zwebrücken, took place, Terex had only recently developed a new control system. This was sold along with the crane factory and the US company’s designer started work on developing a replacement.

In October 2022 Terex announced that it would be launching two new models in its TRT series with that new control system, TEOS, or Terex Operating System. The TRT 80US and TRT 100US offer capacities of 80t/88USt and 100t/110USt respectively, with boom lengths of 42.1m and 47m.

At ConExpo, the company will be showing a smaller crane, the 40t TRT 40US. Like the tiny Tadano, this crane is designed for compactness. It is just 8.2ft, or less than 2.5m, wide, allowing for easy movement on congested job sites or through narrow spaces.

It is offered with a choice of Stage IIIA or Stage V engines, to suit emissions regulations around the world. The four-wheel drive carrier can be operated manually at three forward and reverse speeds, or in automatic mode with five speeds available.

TAILORED TO TILT-UP

If you’re looking to enclose a lot of space – traditionally for factories or warehouses and increasingly for giant battery ‘gigafactories’, chip foundries, or server farms – somewhere miles away from concrete suppliers, tilt-up is an ideal technique. Rather than pouring concrete in-situ using formworks, or transporting prefabricated pieces by road, panels can be pre-cast locally, flat on the ground, and then pulled to the vertical.

It’s a popular technique in the open expanses of the USA. Manitowoc’s latest add-on for its GRT9165, a new heavy duty jib, squarely targets this technique. The company says the 165USt (150t) rough terrain already competes well with other equipment, like lattice and telescopic crawlers, in terms of speed of set up.

The heavy duty jib, which measures 12.5ft (3.8m) long, with two sheaves for up to four parts of line, and a capacity of 68,000lb (30t), aims to add to these advantages. The jib allows operators to operate two hooks, on the boom and jib, together, enabling locally-poured panels, or pre-cast pieces delivered to site horizontally, to be raised to the vertical. An in-cab switch allows the operator to easily move to two-hook operation, with precise control over the hydraulic jib.

Manitowoc says this is a market that is changing rapidly, with hollow, pre-cast pieces increasingly used. As well as being lighter to lift, these make use of less concrete, cutting the overall environmental impact of construction, with CO2 footprints reduced by as much as 25%. This type of work is expected to grow 5.6% annually over the next five years alone, the manufacturer says. Its benefits include efficiency, cost reduction, speed, and more consistent quality.

TADANO HAS A THEORY

Japan has always had its own traditions of rough terrain design. The country’s roadable RTs form the design basis for compact city cranes, often seen as a specialist type of all terrain and frequently used on indoor or highly congested sites around the world.

In recent years Tadano has taken an approach to working in congested sites not seen elsewhere in the world. It has given its GR-130F-1 the nickname ‘Pythagoras’, after the Greek philosopher familiar to generations of schoolchildren for his theorem on right angle triangles. The reason for the name is apparent from a glance at the crane’s lifting geometry: as well as its 15m main boom, it features a 15.9 metre telescoping jib, which can be positioned at any between -3° and 82°.

On housebuilding job sites, the crane can be used to carry loads horizontally over fi ve-storey obstacles. That use had prompted Yokohama residential construction specialist Nakako to buy eleven of the machines, by the end of 2021. The roadable RT offers a compelling alternative to tower cranes on many of its sites.

“Pythagoras is our strategy,” says Nakako founder and president Noriaki Nakamura. “Construction of low-rise houses with two to five floors in some Japanese metropolitan areas cannot be done without Pythagoras because there are many obstacles such as electric wires and highly restricted construction conditions. It can be even said that there is no site that cannot be built with Pythagoras.”

ENERGY RUSH

Rough terrain cranes have long played an important role in the energy sector. On big fossil fuel extraction and refi ning sites, they can often spend their entire working life on maintenance and routine construction work.

As the global energy mix moves away from fossil fuels, towards renewables, hydrogen, and modular nuclear, rough terrains will still have a vital role, handling some smaller generation and transmission components, helping set up wind farm cranes, and in general construction tasks.

The centrality of these cranes to the energy sector prompted the Electric Power Research Institute’s (EPRI) hoisting and rigging cranes user group to feature two Link-Belt rough terrain cranes, the 120t 120|RT and 75t 75|RT, during educational demonstrations at a September 2022 meeting in Lexington, USA.

Matthew Hinman, the group’s principal technical leader for nuclear, explained during the event that, “We use mobile cranes extensively in our industry. We’re demonstrating boom defl ection (with the 120|RT), which is a common occurrence in our lifts. We lift very heavy objects at our power plants and boom defl ection is critical because often the tolerances are very tight. Safety is something we really take a lot of time and attention and focus on in our nuclear power plants.

“With the 75|RT we are tripping a unit, or turning or rending depending on your terminology, but we’re basically taking an object that’s installed vertically, and laying it down horizontally. We do that with pumps, large intake screens, and various structures in our power plants.”