Lightweight high-performance pipelayer

A pipelayer providing higher lifting capacities without adding weight or size to an undercarriage or boom of the pipelayer is disclosed. The pipelayer is designed and sized to have a maximum lifting capacity when the boom is extended from the undercarriage a predetermined, relatively short distance. However, in use the boom often needs to extend further away from the undercarriage, and in so doing the lifting capacity of the pipelayer decreases. The present disclosure provides additional lifting capacity in that extended range by selectively deploying a counterweight away from the undercarriage once the boom is extended past the predetermined distance. In so doing, not only is the lifting capacity of the pipelayer increased, but the size and weight of the undercarriage and boom are not increased.; This enables standard sized undercarriages and other supporting structure to be used, thereby aiding in maneuverability and shipping of the pipelayers, while at the same time reducing manufacturing and usage costs.