CRANES FOR THERMAL POWER PLANT # 2

The picture given in the left of this page is the picture of 1200MT crawler crane used for the erection of steam generator of 660MW . It is to be noticed that the arrangement of counter weight. Counter weight sometimes kept in a extra trolley to balance the load lifting capacity. Choice of high capacity crane for a project is to be done very carefully after considering  all aspect of erection requirement.

In earlier days in India high capacity crane requirement was not there as the unit size was small. Now a days unit size has gone up to 1000MW and above the requirement of high capacity crane is must. Erectors generally hires it from market. There are few agencies available in the market to supply it. However cost of hiring depends on demand in the market. Therefore choice is to be done carefully so that the crane can be used maximum time . The overall duration is to be minimum. For such high capacity crane requires 30 to

40 trailers of minimum 20 MT capacity to transport from its origin to destination. Beside 20 MT capacity trailer we may require 40 MT or above low bed trailer also. It will advisable to discuss the

logistic with the crane supplier. 

To decide the crane type and capacity following aspect to kept in mind.

a. Jobs to be executed by the crane i.e for Steam Generator , ceiling girders erection , WB erections,

column erections , roof structure erections , lift column top tier erection etc.

b. Listing down the jobs , weight and height and also the angle from which erection is to be done.

c. Position of the crane whether it is indie the cavity or outside the cavity . If we position the outside

the cavity then crane capacity will be much higher than inside capacity. Exception is if we use tower

crane.

d.  Type of crawler and size of crawler. 

e.  Overall GA of the crane is required to position the crane.

f. Type of boom required i. Main boom, Jib Boom ( fixed jib or laughing jib , jewellery jib etc ) 

g. It is to be plan in advance that number of times boom needs to changed for work.

This type of high capacity crane requires huge space for assembly and to place in position. It is to be 

appreciated to assemble such crane we require at least 150 mts length space and around 8 to 10 Mtr

width is required for boom assembly. Along the assemble there should be place for auxiliary cranes to run to hold boom in position. It is therefore kept in mind that such place is available in the beginning of the project. As we go along with erection such places will not be available near site. Therefore maximum one or two occasion to be kept for boom configuration changing beside dismantling. Such

crane is always advisable to erect very near the actual site of erection. Otherwise there will be enormous  problem  to  transport them with 140 mt boom height to  site. Some of the crane demands 

road within half a degree of undulation otherwise the  crane will be stopped by its protection. There are three to four companies like Manitowac , Demag , Lieberhrr cranes are very good and well protected by their own mechanism . It is learnt that chinese companies are also making high capacity crane. Beside above issues there are few issues about placement which will be elaborated during steam generator erection.

The picture given below is to draw attention to the bottom of the crawler the plate fabricated pieces on which the crawler are resting. Such type of arrangement are absolutely necessary for the high capacity crane . This will reduce the undulation problem and also crane will be on firm ground and this is necessary whenever we are going for critical load lifting.  Unfortunately such practices are very

rarely being followed in India until and unless it has been insisted. However benefit of the system is

will be seen during SG erection.