A crawler is basically a machine that can lift and move heavy loads. The different parts of the crane are called the house, body, side frame, boom, hoist, wire rope, and bundle. At this point, don't worry too much about the terminology as it is only used in heavy industry to represent certain transport goods.
Unlike hydraulic cranes or truck cranes; the lattice boom crawler cranes does not have a boom. This is not an elimination, but is less necessary because of its superior stability compared to hydraulic or cargo cranes.
The boom or crane shoulder section is mainly a lattice construction for the crane. The frame structure is much lighter than the hydraulic boom crane and the result is a better load to radius ratio.
What I mean is that with a larger working radius you can lift more than just a hydraulic crane of similar performance. This is achieved because the lower boom weight affects the overall capacity of this type crane.
The crawler crane is not fully assembled. They're too big for the streets. That's why they are shipped in practical pieces and assembled on site. This can be a stand-alone project involving a team of professional high-performance technicians such as installers and operators. The crane configuration is determined by the elevator engineer based on the customer's design requirements.