Builders think big27 February 2012
Manufactuers have made the world’s largest tower cranes adaptable to more sites, and builders are using them on large buildings. Cristina Brooks reports.
Previously one-offs, the world’s largest tower cranes have gone into serial production in the last decade.
That’s cause for celebration, because 100t towers aren’t made overnight. When manufacturer Wilbert receives requests for custom towers lifting over 128t, some clients don’t have the time necessary for design, building and testing of a custom crane of these dimensions, says Franz- Rudolf Wilbert, Managing Director.
Mariano Echávarri is head of marketing at Linden Comansa. It has just introduced a new series that includes a 64-tonner. He says those larger cranes must be specially designed to operate with ever-more astronomical heights and loads.
Large towers are in demand from builders that need to get demanding jobs done quickly. Carsten Bohnenkamp, director of sales for Manitowoc’s heavylifting special application cranes, says, “Productivity is a big driver in the demand for special application cranes. Large scale engineering projects are often associated with large scale investments, so customers are looking for increasing productivity on the job site.”
Power build gets bigger
Danish manufacturer Kroll makes the king of all heavy lifting towers, the K10000. With a standard freestanding height of 86m, this tower is able lift a maximum of 240t at the single point radius of 44m. The K10000 is a giant not only in height but also reach: it is provided with a standard jib length of 84m, lifting 120t at an 82m radius, though it can be provided with a 105m jib.
Kroll’s famous K10000 was originally designed to lift nuclear plant generators in Soviet Russia. However, Henrik Nielsen, managing director of Kroll, says modern nuclear plant build increasingly needs even heavier lifters for lifting parts of buildings in chunks.
“It is my impression, from attending various nuclear build seminars, that modularisation is the buzz word and this brings with it fairly few numbers of very heavy lifts,” he says.
Outdoing even this heavylifter, Kroll has as-yet unbuilt designs for a 400t crane, the K25000, capable of lifting 200t out to a radius of 100m with a max single point lift of 400t at a 57m reach.
Kroll’s K25000 and K10000 can be provided with a rail-going portal base for mobility. “Both cranes can be mounted on an undercarriage which enables them to travel with the loads,” says Neilsen.
“The standards were already changing in the 80s for safety reasons, hence the design of the K25000. This crane was designed to take into account the much heavier loads involved in the new designs which the new standards gave birth to.”
Despite the trend for modular nuclear power build, there is no universal agreement on the technique for building these plants, Nielson says. “It is also my impression that there is great uncertainty in the market as to which construction method is the best suited.”
In a nuclear market exposed to financing risks in the post-credit crunch and post-Fukushima era, where investors need the reassurance of a timely ROI, the advantage for contractors remains that the K10000 is designed to work with speed.
Neilsen says that the K10000 cranes can work quickly: “I believe that they can have a positive impact on construction times even today.”
High capacity towers are in demand for work on other kinds of power plants, as well.
Wilbert, a family-owned tower manufacturer in Germany, began as a construction firm in the 1930s, before focusing primarily on tower crane manufacturing in the early 1990s.
Wilbert produces two tower crane ranges with interchangeable modular sections. Its trolley jib crane range goes up to 32t and its luffing jib crane range, called “heavy-lifters” goes up to 128t.
In 2010 Wilbert launched its highest capacity tower overall, the 128t WT 2405L e.tronic luffing jib tower. It can lift 128t from radii of 4–19.5m using its 36m jib and 8 rope falls. Equipped with E66 tower sections, its height can reach 122.9m.
Wilbert sees a steady market for its WT 2405L e.tronic in Europe. “We have lots of enquiries primarily from the petrochemical sector. All current jobs are in Europe,” he says, citing several coal power plants in Germany.
WT 2405L e.tronic has been in demand recently for renewable power build dockside in the Netherlands. It was used at the Eemshaven biomass power plant and Maasvlakte Coal Power Plant—which hosts a pilot CO2 capture project that uses ocean water for cooling—due online in 2012 and 2013 respectively.
Power builders are turning to heavy-lifting towers as they see that they’re more applicable than crawlers, Wilbert says.
“In the past, crawler cranes were executing this work. Compared to crawler cranes, the WT 2405L e.tronic needs less space on the worksite,” Wilbert says.
“In cases where the wind is strong, a tower crane can work longer with shorter breaks. We think this is one of the major advantages, especially when the jobsite is dockside.”
Climbing can be comparatively rapid even for a tower of this size. “By using climbing devices, a tower crane is able to climb faster and higher than a crawler crane,” says Wilbert.
The WT 2405L e.tronic reaches taller heights after Wilbert began offering it (and other towers) with optional E66 sections that increase the maximum height of 122.9m: the height of a tall high-rise. Among other improvements, Wilbert now offers new height-extending E66 sections designed for ease of transport.
“The new E66 rigid tower system measures 6m x 6m x 11.9m. It can be split into web members and mast chords for easy transport. As on the E33, the tower sections will be connected by the proven method of using two large screws at each corner.
Wilbert offers its WT 2405L e.tronic with different bases such as rail-going portals, foundation anchors, cross frames and portals. Clients can use portals to save space onsite as they allow for roads to pass under them. Wilbert says, “A stationary portal is used when traffic has to pass through the crane.”
The more mobile rail-going portal base allows the tower to drive along, although it doesn’t save space, Wilbert says. “This rail-going portal can be used in any industrial sector, with the single precondition that the ground has to be absolutely flat.”
Bridges and Infrastructure
In 2005, the first two 160t Potain MD 3600 hammerheads were built for lifting large concrete components on the Sutong Bridge in Jiangsu Province, China to lift 160t out as far as 18.5m.
The MD 3600 also stretches reaches, lifting a substantial 67.1t at an outreach of 36m.
“The lifting requirements on Sutong Bridge necessitated a tower crane larger than those we have built previously,” says Thibaut Le Besnerais, vice president of special application cranes at Manitowoc. “So we talked with the customer and the MD 3600 was born.” Potain’s special application cranes are currently working on infrastructure projects in other BRIC countries. In Russia, two MD1100 are at work on the Russky Island bridge in Russia, where it estimates they will remain until mid-2012.
In Turkey, Dogus Insaat is using two MD1100 for work on the Boyabat dam; to move conveyor trusses for pouring concrete. They pour the liquid from 9m³ buckets. In addition, they lift reinforcement bar and penstocks.
Purchased exclusively for the project, the towers will remain onsite for about two more years.
Linden Comansa is one of the most active maufacturers currently in this market. It is building its largest capacity tower ranges with infrastructure markets in mind, ringing in 2012 with two newly launched tower models lifting up to 64t.
Linden Comansa’s strongest crane to date, the 64t LC3000 launched this passing November, targets Infrastructure markets, as well as heavy industry and mining.
An early investor in the high capacity concept, Linden Comansa gained the technology for manufacturing 50t Linden 8000S tower cranes after it acquired famous flat-top manufacturer Linden.
Whereas early 50t Linden 8000s were only offered by Linden as custom cranes, Linden Comansa began offering its 48t LC 21 within a series, increasing availability.
In November, 2011, Linden Comansa moved its heavy-duty flat-tops into a new capacity class by introducing a 64-tonner in the new LC3000 series of flat-tops.
The LC3000 series contains two models, 30 LC 1100 and 30 LC 1400, that are each available in capacities of 32, 48 and 64t. The 64t model’s jib length stretches to 80m (262ft) and its freestanding height reaches 88.8m (291ft).
With tie frames the LC3000’s maximum height reaches 198.3m (650ft).
Echávarri says the infrastructure market demands such high capacity cranes. This market has been durable through the recession, while the market for smaller capacity cranes falters.
“This kind of project usually depends on public financing and is the only area of the global construction market that has kept more or less stable in most of the countries,” he says.
“While the sales of smaller tower cranes have decreased due to the crisis, large cranes are in demand for this kind of project.”
With the LC300 series, Linden Comansa has redesigned and improved the design of the 8000 tower, making it more technologically advanced.
“The jib is much bigger: the height of the biggest jib section of the Linden 8000 was 3.8m; while the biggest jib of the LC 3000 is 6.2m high. It can nevertheless be folded to fit in normal transports.”
Structural improvements of the design allow easier transport. “There’s a big difference in the mast sections. The mast section of the Linden 8000 was panelable, but panels were so big, 4m-wide, that they were very difficult to transport.
“Also, assembly of the sections was difficult, with many different pieces to join together.
“The LC3000 has a mast section formed by four quadrants that can be transported easily because they are 2m wide instead of 4m, so the assembly is easier and safer,” says Echávarri.
The redesigned heavy flat top reaches even greater capacities and heights. “In addition, these four quadrants plus one panel for every side and an additional central body, form a new 5.5m wide mast section, developed to reach higher freestanding heights for the cranes of the LC3000 series,” Echávarri says.
“These are the world’s biggest flat-top tower cranes,” says Linden Comansa, While the LC3000 offers 64t by itself, a new standard Powerlift feature will further boost capacity at the furthest jib end of the LC3000 to 10% over load chart capacity.
Previously Linden Comansa’s highest capacity serially produced tower crane was the 48t 21 LC 750 from its LC2100 series. Mexican dealer Groke sold a couple of 21 LC 750 tower cranes to work in the maintenance of two water pumping stations in Mexico City last year.
Echávarri says, “The cranes need to be able to lift the large pumps of the station, which could weigh up to 30USt, including the water inside.”
“Also in 2011 we delivered two 21 LC 750s, with lifting capcities of 24t and 48t respectively, to our dealer in Portugal, Ibergru. These cranes, with other two 21 LC 550, are working on the construction of the Baixo Sabor Dam.
Echávarri says flat-tops, when compared to hammerheads, can save more space on site.
“Often their jibs overlap each other. As the four cranes are flat-tops without pendant lines, they didn’t need to be erected with extra heights.
“In the end, this saves money and time during the erection of the cranes, and similarly, it saves time during the normal work of the cranes.”
The popularity of the 21 LC 750 has paved the way for a new giant in the series expected later this year, says Echávarri.
“In 2012 we will launch a new flat top tower crane that will complete the LC2100 series. We expect to start giving the first details very soon.”
Liebherr’s “heavy load” HC range offers a wide breadth of selection up to 100t, alongside its similarly heavy HC-L range of luffers up to 54t.
The HC range incorporates hammerhead towers in lifting capacities from 40-100t, and includes the models 1250 HC, 2000 HC, 3150 HC, and 4000 HC. It’s used not only for dockside, but also for building power plants and for maintenance in ore mines.
Liebherr’s global dockside market includes BRIC countires as well as European countries likes Spain. Liebherr says that several HC cranes are currently on order for projects in Brazil and in dockyards in Spain.
This range is home the 4000 HC 100. With a maximum hook height of 67.6 m along with a maximum lifting capacity of 100t, it is Liebherr’s largest tower crane. At a working radius of 59.2m with a 2/4-fall, it can lift 58t.
Liebherr provides standard HC cranes with cabins that include features such as air conditioning in the cabin and in the switching station. The tower sections are bolted together for ease of transport.
Liebherr’s HC range towers are in high demand for dockyard work in South Korea, an international shipbuilding hub, where it receives orders for its largest capacities.
In 2008 Liebherr sold its largest crane, the 4000 HC to the Daewoo Shipbuilding and Marine Engineering dockyard in South Korea.
The mammoth 4000 HC 100, one several HC cranes on site, has a working radius of 96m and an under hook height height of 75m.
Liebherr says the 4000 HC 100 benefits from its serial fine positioning mode for dockyard and maintenance work, where parts placement needs to be exact.
In mining there are benefits, too. 2000 HC 60 supplied to the Minera Peñasquito, owned by Canadian gold miner, Goldcorp, was specified with a 65m radius and a 60t maximum lifting capacity. The optional erecting device can reduce the time needed to assemble the tower sections, Liebherr says. Base options for the HC range include stationary bases on foundation anchors, stationary on an undercarriage, mobile on an undercarriage, or gantry in some situations.
High rises need heaviness
Heavy lifting towers are increasingly useful for high rises and other large buildings, manufacturers say.
On such sites, large cement components, sometimes modular, make a heavy crane that can reach high an absolute necessitiy.
Manitowoc, the maker of Potain towers, notes there is a prevailing trend for use of heavylifters by contractors working on high rises and other large buildings with preassembled parts.
Potain’s MD 3600 is equipped with 160t of lifting power to get demanding construction jobs done faster.
The ability of Potain’s MD cranes to assemble buildings in larger pieces and reduce the build time, is a deciding factor for many contractors.
Bohnenkamp explains how heavy towers can reduce other costs. “To optimise manpower and reduce project times, there is more attention than ever on high performance tower cranes. Better lifting ability allows project developers to deliver larger and more complex components to site that can effectively just be “plugged in” to the structure.
“This reduces the need for delicate assembly operations on site, including the corresponding manpower levels, and it also improves building quality,” he says.
Potain is developing its MR range luffers, with lifting capacities of up to 28t, for applications including high-rise work.
“As with changes in other large projects that use MD special application cranes, there are more demands on MR cranes as high rise projects get more ambitious,” says Bohnenkamp.
“In the past cranes around 200tm were common on high rise projects, but today there’s lots of attention around the 600tm category, and beyond.
“We are currently involved with our Potain cranes on a high rise project in South Korea, the LOTTE world tower in Seoul, where Potain MR cranes in the 600tm class are helping build a skyscraper that will reach 550m into the air,” says Bohnenkamp.
A popular option that contractors can select to further increase building speed for this kind of work is Manitiwoc’s newly launched HPL hoist.
Bohnenkamp says, “This whole issue also applies in the world of high-rise buildings. High performance hoists with innovative high-speed technologies offer opportunities to further increase productivity.”
“The sky is the limit”
Manufacturers have stretched their heavylifting ranges tower and some are satisfying their markets, but others still see potential for growth.
Linden Comansa will be launching another high capacity tower within the next year.
Nielsen, with reference to the 400t Kroll already designed, says that an end to the development of maximum lifting capacities is not in sight.
“The sky is the limit with regards to how large the cranes can be made, the challenge lies in making it feasible from a economic point of view.”