Feature: Cranes

Followers of financial results over the last six months or so will be aware that several crane manufacturers have fallen on hard times. Revised forecasts and weak 2014 mid-year results from the likes of Manitowoc and Terex pointed to a fall in demand for cranes in several emerging markets around the world.

But despite the business challenges of the last year, manufacturers have been pushing ahead with new model introductions and a striking number of new innovations.

Although the crane industry is relatively small and served by only a few manufacturers, there have been some interesting new ideas introduced in the last year, challenging some of the design norms, which may have seemed ingrained.

A good example is Manitowoc’s introduction of a variable position counterweight (VPC) to its crawler crane range. The 300 tonne MLC300 and the 650 tonne MLC650 have this feature, which automatically positions the counterweight on a rotating bed, based on changes in boom angle.

Manitowoc says this means customers don’t need to put in as much work preparing the ground for crawler cranes, and in many cases can work on poorer ground with less counterweight for a given lift, without sacrificing safety or capacity. Using less counterweight than with a traditional crawler crane of the same capacity also means less for the customer to purchase and transport from site to site.

“The VPC is game-changing technology,” said Manitowoc’s senior vice president for crawler cranes, John Kennedy. “This new technology will have a significant impact on the lifting industry, as it enhances crane capacities, reduces mobilisation time on the job site, and in the end, saves customers a significant amount of time and money.”

US crane rental company, Bigge Crane and Rigging, was one of the first customers for a VPC-equipped MLC650. Ryan Parker, marketing manager for Bigge, said, “We believe this crawler crane might set the new standard with its upgrades to weight balance, line pull and capacity.”

The company said it planned to use the crane for lifts in the petrochemical, power and infrastructure construction fields.
Meanwhile, All Erection & Crane Rental in the US ordered 10 new 300 tonne capacity Manitowoc MLC300 crawler cranes last year, and was enthusiastic about the VPC feature.

All Erection & Crane Rental president Michael Liptak said, “This is our bread-and-butter capacity range, and being able to create savings for our customers here, at this capacity, is part of why customers choose All. Without hyperbole I tell you that this technology will change the crawler category.”

Rick Mikut, All Erection & Crane Rental crawler crane division manager added, “We can reduce the number of required mats by half. That’s US$ 1,000 in savings per month, and that’s saying nothing of the reduced counterweight loads and the savings realised by reducing the required job site prep area.”

Another interesting innovation from Manitowoc over the last year has been the introduction of a synthetic rope designed specifically for cranes, developed in partnership with synthetic rope specialist Samson.
Manitowoc says the KZ100 hoist rope is 80% lighter than wire rope and is ‘torque neutral’ which means loads will not spin when lifted.

The company also says this type of rope is easier to handle and install, as it is less prone to kinking, bird caging (separation of strands) and damage from other types of cable-spooling issues.
The rope is also said to be corrosion resistant and does not require lubrication.

Before introducing the KZ100 rope, Manitowoc and Samson carried out field and lab tests to check its reliability which used some 7,500 m of rope in 14,000 cycles of testing. Manitowoc also said durability tests were carried out by two independent companies.

Boom Booster

Besides these innovations, the last decade or so has seen a clear trend in the crane industry towards higher and higher lifting capacities. In the early 2000s, a 500 tonne crane might be considered big, or be at the top of a manufacturer’s range. But these days you can buy a 3,000 tonne or even a 4,000 tonne crane ‘off the shelf’.

This trend has been due to specific types of work. One area is the petrochemical industry, where building new plants can require the lifting and placing of extremely large pre-fabricated vessels. The power sector is another where there are similar requirements, particularly nuclear power plant construction.

But a newer application is the wind energy sector, where there is a need to lift heavy nacelles (generator units) to the top of tall masts. And as the sector has grown in maturity, windmills have got bigger and more powerful, which has meant cranes have been needed to lift heavier loads to greater heights.

A new product to address this need is Terex Cranes’ Boom Buster, which is an enhancement system for its 1,600 tonne capacity CC 8800-1 lattice boom crawler crane. Reminiscent of Liebherr’s P boom, which was launched a few years earlier, the Boom Booster is designed to combat the limiting factor of lateral deflection in a crane’s boom. It does this by widening the load bearing chords of the boom, and Terex says it is most effective at steep boom angles with a luffing jib.

The first customer for this system was Belgium-based heavy lift specialist Sarens. Company director Hendrik Sarens said, “For a lift application with 156 metres of main boom, the standard
CC 8800-1 lifts 267 tonnes at 30 metres radius, while with the Boom Booster this capacity is almost doubled, to 465 tonnes.”

Luffing launches

Another trend in the crane sector is the increasing popularity of luffing jib tower cranes. Although more expensive than traditional horizontal fixed jib cranes, they have the advantage that they are more compact, which can be critical on inner-city sites. Another key feature stemming from the fact that the lifting radius is changed by altering the boom angle on luffing jib cranes is that they can work without over-sailing outside the site perimeter. This can be an important liability point, and is a requirement on some projects.

There have been a rush of new launches in this area over the last six months, particularly at the higher end of the capacity spectrum.

Last March’s ConExpo exhibition saw the launch of the first
in a new range of luffing jib tower cranes from Manitowoc’s Potain brand, in the shape of the MR 418, which offers 24 tonnes of capacity and a maximum jib length of 60 m.

Further up the capacity spectrum, Terex has launched the 1,600 tonne-metre CTL 1600, which offers 66 tonnes of lifting capacity, translating to 16 tonnes at the tip of the 75 m maximum length jib.

Terex said applications for the new model include high rise construction, infrastructure and nuclear projects.
The new 66 tonner extends the range upwards from the company’s previous largest luffer, which had a capacity of 45 tonnes. “We made this jump because of the new trends need different capacity,” Riccardo Alba, Terex engineering director, explained. “Time is money and we try to offer the best solution for our customers.”

In a similar class, one of Liebherr’s latest additions to its luffing jib tower crane range is the 710 HC-L 32/64 Litronic, which has a maximum capacity of 64 tonnes, and can lift up to 7.2 tonnes at a maximum radius of 65 m.

And the trend towards higher capacity tower cranes was also in evidence at last November’s Bauma China exhibition.

For example, Yongmao launched a 100 tonne flat top tower crane and 64 tonne capacity luffing jib model at the show. The range-topping STT 2200 flat top has a maximum 70 m jib at the end of which the capacity is 27.2 tonnes. Meanwhile, the luffing jib STL 1460C also has a maximum 70 m jib and the capacity at the end of it is 6.3 tonnes.

Other new launches at Bauma China included an unusual new take on an all-terrain crane from XCMG. The XCWT30 features a normal wheeled chassis, along with a set of crawler tracks. The company said it takes 20 minutes to switch between the wheel and track drives, which allows the machine to traverse different types of terrain.

XCMG also had a new big luffing jib tower crane at the show, in the shape of the 750 tonne-metre XGTL750, which offers a maximum working radius of 60 m.

Besides these, the exhibition was most notable for the new wheeled cranes on show from some of the key manufacturers. Zoomlion showed the new 110 tonne capacity QY110 truck crane, while Sany had the 200 tonne capacity STC2200 at Bauma China.

In terms of new all-terrain cranes, Zoomlion showed the 800 tonne capacity QAY800, which shares several design features with the 2,000 tonne unit it launched at Bauma

China 2012. XCMG meanwhile showed its 450 tonne capacity XCA 450, seven-axle all terrain, which features an 80 m
main boom.

Sany’s newest model at the show was the 600 tonne capacity SAC6000, which was on an eight-axle carrier and offers a 90 m main boom. Like so many cranes in this class, it is aimed at the wind turbine market. Sany says the crane can lift an 80 tonne nacelle – about 2 MW – to a height of 80 m.

Further down the weight class range, there have been other new all-terrain crane launches over the last few months. Terex has added the 130 tonne capacity Explorer 5500 to its range, which offers a 60 m main boom.

With this type of crane most likely to be used on urban construction projects, compact dimensions are a key point. The five-axle carrier is 12.1 m long and 2.75 m wide. To meet different road regulations there are variable axle loads and axle pair intervals. In addition, the boom can be demounted and or the crane can travel with a dolly.

Like the rest of the Explorer range, the 5500 is powered by one engine, rather than the traditional two-engine design for all-terrain cranes – one to move the wheels, the second for the winch and boom. Terex says one engine reduces purchase, operation and maintenance costs. Liebherr is another manufacturer to adopt this design philosophy for some of its all-terrain models.

Meanwhile Tadano has launched the new 100 tonne capacity ATF 100G-4 all-terrain crane and updated the 70 tonne ATF 70G-4.

The ATF 100G-4 has a 51.2 m and offers a maximum radius of 73 m if an extension is used. Power comes from two Mercedes Benz engines. Similarly, the ATF 70G-4 is powered by two Mercedes Benz units and now has a 52.1 m main boom.

So for a sector which is experiencing difficult business conditions, it is perhaps surprising how many new products and innovative new ideas are finding their way into the crane sector.