Lifting Equipment Helps To Build Skyward

Tag : welded cross
Lifting Equipment Helps To Build Skyward Many construction machines are getting bigger and reaching higher By Ivy Chang -- Construction Bulletin, 9/1/2006
Major cities around the world have been competing for therecognition to build the world's tallest building for decades. TheEmpire State Building in New York City and Sears Tower in Chicagoeach held first place in different decades. Then Petronas Towers inKuala Lumpur took over only to be replaced by Taipei 101. Now therace is on for first place between planned buildings in Korea andDubai, United Arab Emirates.
As buildings reach higher and higher, equipment to build and accommodate the height became bigger and taller.Cranes, hoists, mounting baskets, vertical lifts, platforms, andforklifts all serve this market with longer reach, safer, andsometimes compact, equipment that has unique features.
At Manitowoc Crane Group, the Manitowoc model 16000 crawler cranecan have a main boom of 315 feet while the combination of boom andjib can reach a maximum of 433 feet. A capacity enhancingattachment can increase the main boom to a maximum of 394 feet.This model has increased in popularity among contractors whoinstall wind turbines because it also has a line pull of 17.4 tonsand a hoist speed of 697 feet per minute.
MCG also sells Grove mobile hydraulic cranes, National Cranearticulating and telescoping cranes, and Potain tower cranes. Thegroup was formed to meet regional needs and task-specific needsfrom a wide variety of clients and sells the different brandsthrough the Manitowoc Crane Group dealer network.
Titan Machinery, with a network of construction stores in NorthDakota, South Dakota, northwest Iowa, and southwest Minnesota, hasseen a change toward larger cranes. Mike Hall, general manager inFargo, said, "One of the trends that we see in the crane businessis what was considered an average size crane 25 years ago is nowconsidered small. A 30-ton or 40-ton crane used to be considered anaverage size workhorse crane. Now a 60-ton crane is more common.Today's crawler crane market for new cranes is dominated by 100-toncranes, and 165-ton to 250-ton lattice-boom crawler cranes arefairly common."
Projects that commonly require the larger cranes include bridges;wind towers; commercial buildings, such as office buildings, retailspace and factories; and recently, ethanol and other energyprojects, said Hall. "Wind towers are continuing to get bigger,requiring larger cranes to set the generators at the top. Ethanolplants are commonly built for between 50 and100-million-gallons-per-year capacity that, again, require largercranes to set the equipment and steel.
"We are seeing a large demand for 60-ton Grove rough-terrain cranesin our market," stated Hall. "These cranes have really establishedthemselves as reliable workhorses, especially on the energyprojects and commercial construction sites in our area. We've hadvirtually trouble-free performance from our fleet of Grovehydraulic cranes and Kobelco crawlers, which is an important factorin the purchasing decisions of our customers. Crane customerstypically are interested in two aspects in a new crane purchase:lift capacity, commonly referred to as 'the chart,' andreliability. Both Grove and Kobelco make a great crane product andwe're very fortunate to work with them."
New technologies in cranes have helped to make them safer whiletheir capacities have increased. For example, an electronic systemon cranes, known as Load Moment Indicators (LMI), displays theradius of the lift along with the weight. Hall said, "These systemsallow the operator to stay within the safe working limits of thecrane. Often they are a wireless system, which is a newertechnology in this application. Another feature that is new is theability to define a work area by programming the LMI system to notallow the crane to move a load outside a defined work area." Thisfeature is especially useful when working in a hazardous area, suchas near high-voltage lines, other construction equipment , and other buildings and structures.
Grove cranes now have MEGAFORM booms, a patented Grove design withan innovative rounded boom cross-section as opposed to the standardrectangular cross section traditionally available. "This designallows Grove booms to have a much greater strength-to-weight ratioand allows Grove cranes to lift a greater payload at extreme boomlengths," Hall said.
In smaller cities and rural areas, such as in North Dakota, notmany projects exceed 10 stories. "Wind towers, grain elevators andsome refineries offer work that requires tip heights that mayexceed 10 stories," Hall emphasized. "In these cases you typicallysee either a crawler crane or a large all-terrain hydraulic truckcrane on site to do the work. Some of the most challenging jobs donot involve a high lift, but require a pick that is a long distancefrom the base of the crane. It may take a 200-ton crane to make arelatively small pick if the pick is required to be at asubstantial distance from the base of the crane.
"A common example is setting an air conditioning or heat-exchangeunit in the middle of a roof of a large building, such as a mall ora large box store. A small crane could handle the weight if itcould get close enough, but a large crane is required because thesize of the building doesn't allow the crane to get close to thelanding site," he explained.
Telescopic handlers are necessities when working on tall buildings.JLG, the largest manufacturer of telehandlers, recently introducedtwo models, 10,000-pound and 12,000-pound machines that lift to 55feet. JLG is also revamping an older model of the Lull 1044C-SeriesII that will use the same attachments, including the 8-foot towerthat will give the machine a 62-foot landing capability.
Larger telehandlers are the fastest growing segment of the industrybecause larger capacity is becoming a valuable asset when unloadingtrucks and handling large and awkward loads, such as stone, saidJLG vice president of Telehandlers, Ky Kuehling. The need foradditional reach and lift height as job sites get more congestedare a driving force to manufacture larger machines. Taller andtaller buildings are more common in larger cities as space becomesmore limited.
Kueling also sees contractors accepting smaller, compact machinesbecause of their versatility. These machines have a place in thefleet to work on smaller buildings and in smaller areas, he said.JLG makes four brands of telehandlers: JLG, SkyTrak, Lull, andGradall. Recently JLG made two telehandler product acquisitions inEurope to speed its development of smaller-sized units and willintroduce these units at ConExpo in March. Compact units havecaught on rapidly in Europe, according to Kueling.
Gehl Company, West Bend, Wisconsin, which makes compactconstruction equipment , made significant improvements to its RS-Series telescopichandlers with longer boom lengths. The RS6-42 reaches 42 feet andits rated operating capacity has been increased to 6,600 pounds.The new RS8 model, with a rated capacity of 8,000 pounds, is nowavailable with boom lengths of 42 feet and 44 feet. The new boomsshare a common welded box-section design with the DL series, whichmakes them even stronger than previous models.
John Koepf, product manager, said the Gehl RS-Series was recentlyredesigned to improve operator ergonomics and the operator'scompartment. "Telescopic handlers are typically used to movevarious types of construction material, such as concrete block,brick, stone, and bundles of plywood and lumber.
"On large high-rise job sites, you will typically see telescopichandlers moving material at the base of a structure. Thesematerials are being staged for either a crane or an elevator wherethey will be moved toward the top of the structure," said Koepf.
Koepf explained that telescopic handlers use hydraulic power tocontrol the boom and attachments, which hasn't changed much in 30years. "But booms today are easier to operate because oftechnological improvements in the hydraulic controls, such as thepilot-assist controls that Gehl uses in their telescopic handlers."Other technological hydraulic improvements include wireless boomcontrols and using variable-displacement piston pumps and loadsensing systems to obtain better gas mileage and improveproductivity.
"Other technological improvements to the equipment are in response to the Environmental Protection Agency (EPA)engine emission requirements," Koepf stated. "For example,microprocessors are used with electronic sensors to control fuelinjection pumps." Manufacturers must reduce hydrocarbons, nitrousoxide and diesel particulates every year as the EPA requires.
Mustang Manufacturing Company, Owatonna, Minnesota, a company ownedby Gehl, sells a line of compact telescopic handlers. "This linehas booms that reach from 34 feet to 55 feet high," said DougSnorek, marketing manager. Now the company has added the option ofradio remote boom control to several telehandler models which caneliminate the need for additional laborers. Mustang's Radio RemoteBoom Control system allows the telehandler boom to be raised,lowered, extended, and retracted from the remote control. Operatorscan also shut down or start the engine with the remote.
"The remote control system will primarily be used from inside awork platform," said Snorek. "By equipping a worker on the platformwith this system, he will no longer need an operator in the cab toget him into position. He can move the boom to other areas of thestructure he's working on or lower himself when the task isfinished."
Today, options are becoming more common in lifting equipment ; every contractor can own appropriate lifting equipment to perform required tasks on the job, from tall office buildingsto one-level retail stores.
What about the world's tallest building competition? Buildingcontractors use the largest cranes available, longest booms ontelehandlers, elevators that attach to the outside of the length ofthe building, and loaders that can carry the materials to thetelehandlers. Manitowoc said its longest boom, with attachments, is600 feet and that may not be big enough and high enough to work onthe next tallest building.