A pipelayer includes a pilot pressure control unit. The pilot pressure control unit supplies hydraulic fluid to a pilot port of a warm-up control valve so that the warm-up control valve enters an open state when a winch control valve is in the closed state. The pilot pressure control unit drains hydraulic fluid from the pilot port of the warm-up control valve so that the warm-up control valve enters the closed state when the winch control valve is in the open state. The stroke amount from the stroke end of the closed side of the spool of the warm-up control valve when the meter-out opening of the warm-up control valve is fully closed is larger than the stroke amount from the stroke end of the closed side of the spool of the winch control valve when the meter-in opening of the winch control valve is fully closed.