By Laura Hatton01 November 2013
Applications for crawler cranes can vary, with typical jobs ranging from bridge installations to working at sites throughout the energy sector. A result of this has meant that manufacturers are developing models with increased versatility, efficiency and improved transportation.
Wolfgang Beringer, sales promotion at Liebherr-Werk Ehingen, explains, “When designing a crane we always look at transport optimised dimensions and weights. We also have to offer a variety of boom systems for each crawler crane model, so that our customers can use the crane for a wide range of applications. For some applications, such as wind power, specially adapted attachments have to be designed.”
“Everything related to crawler cranes is about transport and cost of operation,” adds Guntram Jakobs, Terex Cranes product manager, Terex, “So everything in our crawler cranes has been engineered for transport optimisation. Safety is also important and all our crawlers come with the fall protection system.”
Efficiency and versatility are other factors influencing the design of crawler cranes. Part of this development is due to a shift in work type and job sites for crawlers, as a spokesperson from Manitowoc explains, “Crawler cranes are often called upon not just to lift but to travel while carrying a large load. One of the most interesting crawler crane applications are barge work, where a crawler crane is installed on a special platform on a barge for use at sea. Such barge cranes perform material handling, installation and general construction work.”
“With rental rates being pushed by construction and rental companies having their profits tightened profitability is really important. As a result efficiency and versatility are driving crawler crane development,” Jakobs says.
Examples of how efficiency and versatility have driven crawler crane development can be seen in a number of the new crawler cranes that have entered the market this year. From manufacturer Manitowoc, for example, is the 165 tonne MLC165 lattice boom crawler, which is designed for contractors and rental houses in the global market.
Jerry Maloney, global product director at Manitowoc, describes the crawler, “This self-rigging crane is very easy to assemble and disassemble. It can install and remove its own counterweights and tracks without the need of a support crane. In addition, it has a three metre component width and modular assemblies for easy transport over the road. It is loaded with all the latest technology to benefit everyone from the owner to the operator.”
Steven Dick, technical sales support co-ordinator at Manitowoc, explains more, “Our engineers designed the MLC165 to facilitate general contractor activities like pile driving and moderate clamshell or grapple work. We like to think of the MLC165 as a versatile tool.”
The MLC165 has a maximum boom length of 84 m and optional fixed and luffing jibs. The maximum boom and fixed jib length is 93.4 m and the maximum boom and luffing jib reach can be increased to 102.8 m.
Also new to the crawler crane market is the 248 HSL from Link-Belt. The new 200 US ton (181 tonne) crawler offers a variety of boom systems, including a main boom with a maximum length of 86.87 m, a fixed jib with a maximum length of 30.48 m, a luffing boom with a maximum length of 48.77 m and a 54.86 m luffing jib. For ease of transport the counterweight can be removed.
“The HSL line of Link-Belt lattice crawlers represents our next generation of HYLAB cranes, which Link-Belt first introduced over twenty five years ago,” Pat Collins, Link-Belt senior product manager, lattice crawler and telescopic crawler cranes explains. “The 248HSL joins the 238 HSL and the recently upgraded 298 HSL in the mid-range 150 to 250 ton [136 to 226.8 tonne] market. It has been built for general lifting duties including tilt wall, bridge work, steel erection and pile driving to name a few. ”
Sany has also introduced some new crawler crane models to the market, including the SCC8500. Suited for jobs in the energy and infrastructure market, the crawler has 10 possible boom configurations for main boom, fixed jib and luffing jib. The main boom length is 108 m and the luffing jib is 72 m; when configured with the Ultralift system these measurements are increased to 121.1 and 84 m respectively, the manufacturer adds. Power comes from a 447.4 kW Cummins diesel engine.
Also from by Sany is the mid-range SCC8150. It can be configured with an 82 m main boom and a 31 m fixed jib. Capacity is 150 tonnes and it completes the range of crawlers, the manufacturer said. Power comes from a 316 kW Tier 4 interim Cummins engine.
“The SCC8150 gives contractors a new option in a competitive segment of the market,” Kyle Nape, senior vice president, Sany America Lifting Group, says. “Our new crane delivers a combination of control, performance, operator comfort, power and dependability that meets and exceeds the requirements for a machine in this weight class.”
Over the last 12 months there have been some new additions to the crawler crane market at the higher end of the capacity scale. Although there are nearly no limits to how much a crane can lift, the higher a crawler’s lifting capacity, the greater is the design challenge.
“Concerning lifting capacity there are nearly no limits,” explains Beringer, “but these huge cranes include counterweight systems that need a lot of space. So the challenge is to design cranes which can work in constricted areas, such as in refineries. Our new LR 11000 has been designed according to this demand.”
The LR 11000 is Liebherr's reaction to growing market demand for hoisting work in the 1,000 tonne segment, Beringer explains, and is suitable for handling offshore wind turbines and their foundation structures at ports. It fills the gap between the LR 1750 and the LR 11350.
The LR 11000 can have an S-type main boom and a W-type luffing jib. It can also have a PowerBoom system with a heavy luffing jib, the design of which has been taken from the 3,000 tonne LR 13000. “The main S boom operation is possible with a 1,000 tonne head or a 650 tonne head,” Beringer adds.
To be able to work in confined areas the crane has a track width of 9.2 m. It operates with a maximum 250 tonne slewing platform ballast, 90 tonne central ballast and up to 450 tonne derrick ballast. “The derrick ballast is adjustable up to 20 m and with a fixed lattice guide it can be operated at radii of 20, 25 or 30 m,” the manufacturer adds.
For ease of transport the LR 11000 has a transport width of 3.5 m and a transporting height of 3.2 m. “The lightweight lattice sections can also be retracted into large heavy sections to reduce transport volume,” Beringer adds. In addition, there is a removable A-frame, including reeving system, fall protection equipment and stacking supports for lattice sections.
Also new from Terex is the 650 tonne Superlift 3800. The lattice boom crawler crane has a maximum load moment of 8,426 tonne metres. Its boom system in SWSL1 configuration is made up of the main boom plus the luffing jib. The only attachment needed is the LF, a light fixed jib.
Jakobs explains further, “Normally crawlers have special boom combinations, so you have a boom for wind and a boom for heavy lifting. So, with one base machine, you will have to have multiple boom systems. However, with the Superlift 3800 there is only one major boom system, so you can use the same boom sections for different applications.”
Another area that Terex has concentrated on is lowering transport and operation costs. The crawler has fewer components for transport and counterweight slabs that that can be stored separately. In addition, an assist crane is not required to erect the boom, even when the crawler is configured with a boom length of more than 150 m plus the jib.
Operating cost is also reduced with the luffing jib, which has a runner with a one line hook; this means when working on a project, for example a wind farm, the operator can lift small objects such as tools, to the top of the turbine very quickly.
Future super lifters
The demand for heavy lift crawler cranes is forecast to continue over the coming years, especially for the increasing work in the nuclear and other energy industry sectors. Whether or not a new generation of super heavy lifters will emerge to meet this market demand is something that cannot be predicted. As Jakobs explains, “Cranes have to be profitable for the owner. This means they can take jobs and perform them efficiently. For us, crawler cranes need to be efficient and something that will help our customers with their business.”
“Generally speaking, the job and lift requirements will dictate what size crane is utilised,” Collins adds. “In the end, the lifting needs must justify the crane size and the cost that comes with a larger crane.”