Advantages and Disadvantages of Large-capacity Luffing Jib Tower Crane and Level Jib Tower Crane

Luffing jib tower crane and level jib tower crane are two kinds of common models. Both models are widely used but they differ in their structure, operating principle and application field. Luffing jib tower crane is mainly used in large project and industrial equipment installing field where large lifting capacity, high perching accuracy and high safety are required for lifting large members and equipment component. Level jib tower crane is mainly used in common civil building field where fast lifting and inaccurate perching are required for lifting building materials. Both models have advantages and disadvantages in different application fields, therefore we can plan a key role in determining which model should be selected.

Brief comparison between the two models in large power station construction field
Description	Luffing jib tower crane （Large Capacity）	Level jib tower crane （Large Capacity）	Comparison results
			Luffing jib type	Level jib type
Application field	Widely used and it can replace level jib tower crane	Relatively narrow in application field and it can not replace luffing jib tower crane	Superior	inferior
Laying out flexibility	Good	Bad	Superior	Inferior
Design, manufacture and manufacturing cost	Complex design and manufacture and high manufacturing cost	Relatively easy and low manufacturing cost	Inferior	Superior
Safety	High	Relatively low	Superior	Inferior
Anti-wind ability	Strong	Weak	Superior	Inferior
Perching accuracy and efficiency	High	Low	Superior	Inferior
Lifting and derricking speed	Fast	Slow	Inferior	Superior
Lifting capacity at large radius and the same moment	Large	Small	Superior	Inferior
Maximum radius at the same moment	Small	Large	Inferior	Superior
Safety and suitability of cooperative operation	Strong	Weak	Superior	Inferior
Erecting and dismantling cost	Low	High	Superior	Inferior

As the above comparison, luffing jib tower crane has great advantage over level jib tower crane in power station construction field, which has been confirmed by more than 100 power stations construction in china. Level jib tower crane is widely used in plant construction of power station as auxiliary tool while luffing jib tower crane definitely predominates in boiler lifting. It is not the only choice to use luffing jib tower crane for boiler lifting, which can be achieved by cooperation between large crawling crane, furnace handling crane and large level jib tower crane but also economical efficiency, safety and plane layout need to be carefully considered.


The following issues need to be carefully considered for large level jib tower crane

• Plane layout feasible or not? Large project needs simultaneous operation of many sets of cranes as it is very important for dodging of cranes from each other and from buildings. Otherwise, it may possibly lead to very low efficiency in operation, high risk and unguaranteed time limit for a project. But luffing jib tower crane is very flexible in boom range no matter, it is in working condition or nonworking condition for conveniently dodging the other cranes and buildings in construction field while level jib tower crane can not do that either in working condition or non-working condition.
• Are local climate especially wind frequency and wind speed suitable for using level jib tower crane? According to safety code, the slewing and brake mechanism of the crane must be released in non-working condition (i.e. free slewing condition) to ensure that the boom can freely slew with the wind for reducing wind influence to crane. Take dodging into consideration, whether the boom of the level jib tower crane is allowed to freely slew with wind or not? Luffing jib tower crane can simultaneously release slewing and brake mechanism and locate the boom in small range for the purpose of extensively reducing wind influence to the crane and avoiding collision between the boom and other cranes and buildings when freely slewing in non-working condition.
• Whether the cooperative operation of two sets of crane is needed in present and future project? Owing to the economical efficiency and shortage of crane with more large specification, the cooperative operation of two sets of cranes Is adopted widely. For cooperative operation, luffing jib tower crane has great advantage while level jib tower crane is very dangerous to use for structural limitation or even unavailable for interference between the crane and the building.
• Which country or area can your crane be used at present or in future? Level jib tower crane is prohibited in many countries and many areas. And landowners in many countries are entitled to have command of the air at limited height so that you can avoid lawsuit if you do not let your crane breach other people's sovereignty. According to the data of constructed power plant in China, most of the sites adopted luffing jib tower crane as the main lifting machinery that the customers can be benefited for scientifically choosing proper crane model.

As per the "Feasibility Study Report of Large-scale Machinery Arrangement for 1000MW Coal-fired Unit Boiler Lifting" Published on "construction mechanization" magazine, November, 2007, comparing with traditional machinery arrangement plan, the adoption of FZQ series luffing jib tower crane by Finehope (www.fhjs.net) has higher efficiency especially cooperated with auxiliary crawler crane, of which the plan can improve the economic benefits greatly by reducing the operating cost, assemble and dissemble cost and foundation treatment cost as well as engineering construction cost. Based on the large scale machinery performance condition within China, it can be concluded that the arrangement plan of adopting one FZQ1380 and one FZQ 1650 by Finehope for the boiler lifting shall spread.