Pipelayers and sidebooms are construction vehicles manufactured for the means of maneuvering pipeline components during assembly. These vehicles somewhat resemble a crane, as they are mounted on caterpillar tracks, the lifting mechanism includes an articulated mast, a hoist system creates a mechanical advantage, and counterweights stabilize the equipment.
Pipelayers differ from sidebooms because the vehicle platform, mast, crew cabin, and counterweights are mounted on a rotex gear. This allows the vehicle to pick-and-place materials in a 360° circumference. Pipelayers typically do not have as high a capacity as sidebooms, but they are more versatile in pipelaying environments. Sidebooms do not incorporate a rotating platform, and the mast overhangs the left or right side of the vehicle. Pipelaying operations can only occur on one side of the vehicle. Furthermore, pipelayers cannot be converted from a crane, but many sidebooms are modified, heavy-duty bulldozers.
Sidebooms and pipelayers must have a low center of gravity. Some pipelaying vehicles are capable of lifting more than 100 tons. Diesel engines provide locomotion, as well as power for the hydraulic systems. Pipelayers and sidebooms are deployed in teams which are commonly called pipeline 'spreads', due to the fact that multiple work crews spread out to create an assembly line-like process for pipeline installation.
Images credits: Eng-tips; Volvo