Consider the following statements regarding the dependency of crane load capacity :

1. The size of the crawlers is not a factor due to diminutive mounting which decreases the stability of any footing.

2. The strength of the boom is also one of the major governing factors in establishing load ratings, and any extension of the boom reduces the rating. Lowering the boom also increases the clearance radius and thus reduces the rated capacity.  

3. The counterweight is added to the after-end of the machine. Manufacturer’s specifications provided standard and maximum counterweights and also the crane ratings. Counter weights may be increased to a specified maximum, but the operating radius must not exceed that given by the manufacturer. 

Which of the above statements is/are correct ?