Cranes have contributed to the rise of civilization for many years in the construction industry. The ancient Greeks invented the first crane sometime in the sixth century as a tool to lift massive loads. According to Chiu (42), such evidence that points to the use of cranes by the Greeks can be found on distinct holes that are visible on stones, which indicate the use of a form of lifting mechanism. Back in those days, the basic features of the crane included an elongated wooden beam, which was attached to a rotating base and a rope attached around a drum that was driven by a wheel or a treadmill. One end of the rope was linked to the tip of the wooden beam while the other end had a hook that aided in the lifting of the heavy loads like large stones.
Further, advancement in the use of crane led to the development of a winch and pulley hoist that replaced ramps as the main means of vertically lifting loads. Mostly, Egyptians and Mesopotamians used this type of crane. Most of the pyramids in Egypt consist of large stones that could possibly have not been placed by human hand alone. This provides evidence of the use of cranes in early civilizations. In the past, the lifting capacity of the cranes was limited. However, innovation has enabled the lifting capacity of modern cranes to increase tremendously with loads weighing up to 1000 tons being carried by the cranes.
According to Vaughan (7), tower cranes are mostly used in the construction of multistory buildings. They are mostly stationary but may move slightly short distances on site if such a need arises. It consists of a lattice tower, which supports a horizontal boom (Day and Benjamin 259). The horizontal boom extends on both sides of the tower with one end, usually the shorter having a counterweight. The other end normally has a hoisting mechanism, which runs back and forth on a trolley.
Tower cranes range from heights of 50 feet to 250 feet. At higher heights than these, the crane is normally fastened to the building at several points to increase its stability. The tower cranes are built onsite and can be built on the skyscrapers too. The base of the tower crane is normally concrete. It is common to find several tower cranes at a construction site in case the projects are fast track construction projects. According to Jha (293), tower cranes offer a certain advantage of other types of cranes at a construction site. Since they appear over the work site, they can place a load anywhere within their radius of operation without interfering with the structure being constructed.
These cranes have a form of tracks that allow them to move within the project site. These tracks are especially significant if the ground of the site consists of poor soil, which can result to sinking of the crane. If the crawler cranes are to be used at another project site, a truck will be required to move them (Jha 296). Crawler trains can be very dynamic and can have different configurations to perform different tasks at the project site (Gransberg, Popescu and Ryan 112).
In this type of crane, the whole structure of the crane including the boom, engine, operator’s cabin and the counterweight rest on a special truck (Jha 295). Truck cranes are mainly useful in situations where lifting projects are short term. Significantly, setting up tower cranes for short-lived projects can be costly and in such situations, the truck cranes come in handy. The truck cranes can be moved easily on public roads as well as rough terrain. Efficiency is ensured by making certain that the truck if resting on a firm ground level during operation.
In factories and warehouses, there are special types of cranes referred to as bridge cranes. The bridge cranes normally operate in a Cartesian space. A trolley moves along the bridge. The trolleys motion is perpendicular to the motion of the bridge (Vaughan 6).
Modern times have seen the development of cranes with enhanced capabilities. Cranes can now lift loads of up to several hundred tons. One of the major innovations has been the introduction of the mast crane concept. According to Schempf (1), the mast crane has some elements that make it different from other crane types. The mast crane has no tail swing thus it takes very little deck space. Additionally, its outreach at a certain capacity is often larger than for ordinary cranes. Additionally, to increase the versatility of offshore cranes some of the innovations have included the introduction of small, trolley mounted hoists (Schempf 1). These have increased the speed of the cranes during transfer of loads.
New technology such as the Transi-Lift system design of cranes has helped in the construction activities of nuclear sites. The new design allows the crane to lift heavy loads at extreme radiuses and at the same time reduce the effect of the crane on the ground during the operations (Stemp and Walewski 792). As the number of heavy-duty operations continues to increase the Transi-Lift design, will come in handy especially in the construction of nuclear plants
The use of cranes will continue to get more usage in the construction sector. In industrial construction, reduction of cost will depend on the manufacture of large components at off-site locations and installation of such components using heavy cranes. As such, efficient heavy cranes will be required and it will be necessary to use such designs as the Transi-lift design that minimizes the effect of the crane on the ground pressure. Additionally, using smaller hoists and trolleys will increase the speed of the cranes and in the process will reduce operating time. Safety is still a main issue in the construction industry. Height considerations for the tower cranes need to be taken into account incases heights exceed the recommended heights. Consequently, application of fastening may be required to guarantee the safety of operation of the crane at such high heights. Therefore, the operators will need to be adequately trained to ensure that accidents do not happen or are minimized.
Cranes simply the work best in the constructions sites. As such, more effort is necessary in the development of research on new designs that may be applied in other areas of construction and not be limited to shore line operations for ships and the loads of containers. Additionally, prior to the use of a crane, project managers need to understand the requirements of their projects to ascertain the best crane for the task. For instance, truck cranes may not be suitable for the construction of skyscrapers. In such situations tower cranes may be more suited for the task.
Works Cited
Chiu, Y.C. An Introduction to the History of Project Management: From the Earliest Times to A.d.1900. Delft: Uitgeverij Eburon, 2011. Print.
Day, David A., and Neal B. H. Benjamin. Construction Equipment Guide. 2nd ed. New York: Wiley, 1991. Print.
Gransberg, Douglas D., and Calin Popescu. Construction Equipment Management for Engineers, Estimators, and Owners. Boca Raton, FL: CRC Taylor & Francis, 2006. Print.
Jha, Kumar N. Construction Project Management: Theory and Practice. New Delhi: Dorling Kindersley, 2011. Internet resource.
Schempf, Jay. "Offshore Industry Benefits By Innovations In Crane Design." Offshore 66.6 (2006): 100. Business Source Complete. Web. 23 Nov. 2014.
Stemp, Bruce A., and John Walewski. "Lampson Transi-Lift Mobile Crane: Concept, Design, And Use." Journal of Construction Engineering & Management 137.10 (2011): 785-792. Business Source Complete. Web. 23 Nov. 2014.
Swartz, George. Warehouse Safety: A Practical Guide to Preventing Warehouse Incidents and Injuries. Lanham, Md: Government Institutes, 1999. Internet resource.
Vaughan, Joshua. Dynamics and Control of Mobile Cranes. Miami: ProQuest, 2008. Print.
