1. Why we use tower crane

Tower cranes are normally used for lifting heavy building materials, machinery equipment, and other objects at construction site. They are usually located beside/on buildings with exact positioning to handle heavy loads. It has a long working range, big load capacity, flexible height and working range, etc. With these advantages, using a tower crane can reduce labor intensity, increase efficiency and shorten construction time.

2. Self erection tower crane can be classified by outline into topkit, topless, luffing jib tower crane, their advantages and disadvantages are as followings:

(1) Topkit tower crane

Advantages: initial type of tower crane, mature technology, low cost.

Disadvantages: with tower head, installation height will be higher than other types'; jib shall be lifted and fixed as a whole, so assembly and disassembly require higher load capacity of lifting equipment which follows high cost. Require a bigger height difference when tower cranes work closely.

(2) Topless tower crane

Advantages: Jib can be fixed as per section separately so that the requirement to the lifting equipment may be lower than topkit type's. The jib can be dismantled easily so that it's suitable for site that require a flexible working jib. Without tower head, that lows the tower crane height and is suitable for many tower cranes work together. Jib construction has a long life time and high security. Installation cost is lower than that of topkit type.

Disadvantages: Producing cost is higher than topkit type's.

(3) Luffing jib tower crane

Advantages: Suitable for working at narrow space and many tower cranes work together. Normally max load is higher than other types'. And luffing jib tower crane is also applicable for some place that jib over working area not allowed.

Disadvantages: The price is higher than other two types of tower crane. The cost of assembling and disassembling are high too. Because the luffing jib don´t have trolley mechanism, the working process are slow.

Each type of tower crane can be classified into stationary, travelling and internal climbing type used for differenct working conditions.

3. Necessary data for selecting a tower crane

(1) Height under hook(HUH); 

(2) Working range(Jib length); 

(3) Max. load; 

(4) Tip load; 

(6) Mechanism type(Normal/Frequency control); 

(7) Tower crane type(stationary/internal climbing/travelling, topless/topkit/luffing jib)