Tower Cranes Making Their Mark
Demands from core infrastructure projects in construction and power segment are calling for increasing use of tower cranes. Partha Pratim Basistha reports.At par with traditional construction demand, requirement from real estate projects, tower cranes are now finding their growing applications for high end infrastructure projects, pertaining to power, refinery and other range of industrial projects. To meet the assorted growing requirement from the core infrastructure sector, tower cranes manufacturers and distributors are offering the required product mix with requisite customer support in the same order.
Mr. Mattoo says, "to ensure that the cranes are able to lift higher loads, the steel we use in our cranes are of rigid variant." Manitowoc manufactures Potain tower cranes in India with a lifting capacity of 5–16 tonnes at its manufacturing facility in Pune as per European design. The cranes are produced both for the domestic and export market.
According to Mr.Mattoo, "Manitowoc is eyeing the high end construction sectors for its tower cranes in a big way and to provide requisite customer support we bank on Manitowoc Crane Care, our comprehensive after sales service that offers experts diagnosis and repair to customers."
Examples of usage of tower cranes in high end complex construction projects are growing in India. With one of world–class, recently completed Mumbai-Worli Sea Link project. Tower cranes were extensively employed in the land mark project to lift pre-fabricated steel structures brought at the piers of the bridge as well as for lifting raw materials. The cranes were also used for pouring concrete at the pier level and also at the ground level not accessible by concrete boom pumps at the project.
The Escorts - Huata cranes have been finding its application in high end projects undertaken by contractors consisting, IVRCL, NCC, Gammon, Maytas for its dam projects and for Indu Projects and others. The cranes have been finding its usage also with cranes rental companies for big projects as well. However, one of the significant industrial construction projects where an Escorts - Huata 5013 crane is finding use, is for a construction of concrete silo project at Aligarh. sBeing executed by contractor Gannon - Dunkerley, the project involves construction of a concrete silo at a height of 110 metres. As per Mr. Malik, "the project is complex and have to be completed within a compressed time schedule and our Escorts - Huata having a maximum lifting capacity of 6 tons and 1.3 tons hard an extended jib of 50 metres is working at to complete the same swiftly."
Escorts - Huata tower cranes are available in six models. The maximum with a lifting capacity of 18 tonnes and minimum of 3 tons at an extended jib of 70 metres. The cranes are made of low carbon steel and come with interchangeable mode. The cranes are European certified and are equipped with load limiters, trolley limiters etc. As a part of customer support, ECEL undertakes the installation and maintenance of the cranes through its engineers, trained in China based across its pan India service network.
Increase usage of tower cranes for core construction projects have been exemplified by Chinese Construction Equipment conglomerate. According to Mr. Lee Ling, Sales Manager - South Asia, Hunan Zoomlion International Trade Co Limited, "major construction projects where Zoomlion tower cranes have been used in India includes, office building, apartment, business center, power station, airport, steel plants, metro projects, and so on. The tower cranes have been bought by contractors involving, L&T, MTG, Ahluwalia, Punj Lloyd, M&M, JMC, Birla, K.Raheja, Unity infra, and others."
Mr. Lee informs, "tower crane models finding increasing acceptance in India are of 6 tons (TC5013B-6) for office building, apartment, business center, and shopping center. Whereas 10 tons (TC6020A-10), and 12 tons (TC7030B-12) for big office buildings, power stations, airports, steel plant projects."
Bulk of Zoomlion tower cranes sold to India are having the working height of about 40-80m. Zoomlion, which entered into the Indian construction equipment market in 2004 distributes its Chinese made tower cranes through the distribution tie-up with Action Construction Equipment (ACE).
According to Mr. Lee, "Zoomlion tower cranes have about 30 models with lifting capacity varying from 6 ton to 63 ton. The cranes are equipped with features comprising, mechanism and electricity protection. Mechanism protection equipment includes wire rope anti-broken device and trolley shaft anti-broken device. The electricity protection equipment includes the height limiter, slewing limiter, trolley limiter and travel limiter, moment limiter, overload limiter, and anemoscope."
Zoomlion, which claims to have about 30% market share in India in tower cranes has sold over 300 units so far. According to Mr. Lee, we will develop some of our big tower cranes, which are mainly for the big projects such as the power station, steel factory, bridge, airport and so on, to enlarge the field of applications of our tower cranes in India and thereby increase its sales.
Zoomlion provides the requisite customer support through its dealer ACE. The service support includes installation and decommissioning of the cranes and periodical checks of the tower crane at the jobsite. The company has an established after sales service station and spare parts stock across India with engineers in place. Zoomlion also offers both flat top and hammer head tower crane and luffing tower crane. Besides these, it also offers outrigger stationary, chassis stationary, mobile types for all of our tower cranes, and bolt stationary and inner-climbing type for some tower cranes.
According to Mr. Lee, "Indian tower cranes market has enormous potential, and more manufacturers have entered or are planning to enter into the market making competition acute. Most tower cranes in India are for the residential projects, so the small tower cranes are most popular in the market, especially for the tower cranes with max load capacity of 6 tons. However, the Indian Government is spending a lot of money on infrastructure, big tower cranes with heightened lifting capacities would be needed for the infrastructure projects such as power station, steel plants, bridges, and so on."
Power SegmentAmong high end projects, one of the growing application area of tower cranes is power plant construction projects. This is one of the high end construction project sectors and perhaps the most critical, owing to the construction complexities involved, which would place demand for tower cranes in a bigger way.
India has set up a target of 70,000MW of power capacity addition during the eleventh plan (2007-2012) and further to 1,00,000MW during the twelth plan period. The power capacity requirement would be met through a requirement of thermal, hydro and nuclear power projects, all which would require deployment of tower cranes in a big way at project sites.
Deployment of tower cranes at power plant project sites is necessitated dually by the construction requirement and also by the new constructions stipulations laid by the government. As per Mr. Mani Mathivanan, General Manager-Projects, GMR Energy Limited, "newer norms, laid by government, like increasing the height of the chimneys at thermal power stations to avoid environmental hazards has also made it imperative for use of tower cranes with greater heights in construction of thermal power projects." He informs, "as per new environmental norms, laid by Ministry of Environment, chimneys have to be constructed at a height of 275 metres height and for cooling towers with a height of 80 metres putting requirements of tower cranes in big order."
Similar views are endorsed by Mr. R.K Singh, Purchase Officer, Equipment Purchase Division, Afcons. Afcons has been using couple of tower cranes, with a height of 67 metres at its construction site at Cochin where it is constructing a liquefied natural gas tank at a height of 52 metres for LNG Petronet. It is also using tower cranes for the construction work of Koldan Hydro Power Project in Himachal Pradesh for construction of dam involving 52 metres height.
Application necessity of tower cranes in power projects can be described best in terms of the construction complexity the projects offer. In hydro power projects while the equipment is used to lift construction material, the cranes are also essentially used to lower turbine shaft, which could weigh between 2-15 tonnes, 40-50 metres below the ground. Lowering of turbine shaft in hydro power projects can be described as a critical application area. Followed by lowering of turbine shaft, tower cranes are also used to construct the supporting structurals, another critical application area. Tower cranes have delivered their due application for construction of Jurola dam project at Mehboobnagar in Andhra Pradesh. The project involved lifting construction materials for the dam project and also lowering turbine shaft and materials for the supporting structure.
While circuitous construction requirement would put need of tower cranes, it is actually the project requirement that would lead to the demand pull for tower cranes from the power sector notably from nuclear projects. This is based on the fact that the government has lined up important nuclear projects for development.
India is planning to set up a slew of nuclear power stations across the country with the sites being chosen so far are Jaitapur in Maharashtra, Pati Sonapur in Orissa, Haripur in West Bengal, and Mithirvirdi in Gujarat. Six to eight reactors of 1,000-1,650MW are proposed to be installed at each nuclear park. According to Mr. Sudhinder Thakur, Executive Director, Nuclear Power Corporation of India Limited, "the government's ambitious programme to enhance the nuclear power generation of the country to 7280MW from the present 4120MW, would put in great demand of tower cranes of various heights with varied lifting capacities for undertaking the lined up projects. Even there would be demand for special application tower cranes with luffing arrangements."
Equipment for Heavy Lifting
Syncon has delivered its Jianglu JL 5515-QTZ80F for construction requirement of JK cement plant at Gujarat. The crane has a maximum hoisting capacity of 8 tonnes and a jib length of 55 metres. Syncon has also delivered one of its JL 8032-QRZ500 for construction of Ambuja cement plant at Sirohi in Rajasthan. The crane which has a maximum lifting capacity of 26 tonnes has a jib length of 80 metres. Syncon's Jianglu tower cranes are also finding their applications in osther high end projects across the country.
As per Mr. Mehta, "our tower cranes have advanced features for effective functioning in high end as well as real estate projects. We provide tower cranes that have features involving slew and hoist motors having brush less motors, split type mast with pin joint." He says, to make the cranes suitable for infrastructure projects Spartan cranes are available with wide range of capacities and with stationery inner climbing and rail mounted versions (suitable for dam construction projects). The company claims about offering luffing crane with 45 metres jib length having maximum 10 tons load and 3 tons tip load with 360 degree coverage area for a real estate project in India. Further, it claims to have offered 50 ton tower crane and 9 tons tip load tower crane with a 70 metre jib length for high end construction project.
CMAC, which provides on site training for smooth and safe functioning of its equipment provides its cranes manufactured from 235-345 steel grade. It has recently supplied tower cranes for construction of cement plant in Andhra Pradesh. The company has also supplied good number of tower cranes for multiplexes and shopping malls across the country apart from supplying tower cranes for construction of pre-casted fabricated building in Saudi Arabia.
Fore most of the safety aspects that needs to be taken into account is the wind velocity in the vicinity of the infrastructure project. According to Mr.Ram Babu, "pressure due to high speed winds may lead the crane to derail or collapse. Hence before putting in the tower crane the wind velocity needs to be checked." Wind pressure in tower cranes are determined with anemometer where a crane operator can read the wind velocity. Cranes are safe to operate in wind velocities of upto 40 Kmph. Programme Logic Control Devices assist in automatically shutting down the crane when the wind velocity is exceeded.
Further according to Mr. Babu, "since tower cranes in infrastructure projects has to work in an increased heights, the foundation has to be strong through proper raw materials. No compromise has to be done in this account additionally, plumb line has to be perpendicular as slightest deviation from the same would render the working output inaccurate. Besides, anchoring support has to be quite strong."
The other safety precautions that need to be taken into proper consideration during the operation phase of tower cranes include, proper maintenance of the rail track on which the tower crane is working in infrastructure projects has to be ensured. It is quite essential to use little worn rail for proper bearing surface. Rails should be absolutely parallel and well bedded down on a solid base. Tracks should be earthen. It should be straight to prevent derailment of the tower cranes at the job site.
Moreover, while extending the height of the tower cranes precaution has to be observed. Also while working in clusters the site planning has to be done properly so as the cranes do not collide during their slewing operation. Most importantly, overloading should not be allowed under any circumstances as majority of accidents in tower cranes occur due to lack of proper information on loading or intentional overloading. However, the information on safety aspects should be provided by manufacturers and distributors. All these steps would lead to hazard free use of tower cranes in infrastructure projects. Not to mention their increased use for the time to come.