This plant for manufacturing a rigid pipe for drawing up deep water for a marine thermal energy plant is characterized in that it comprises a floating platform on which there is installed a continuous production device in the vertical axis of the pipe, including a first stage of winding webs of fibers impregnated with resin about a winding roll for the partial crosslinking thereof, said wall being formed by modular elements in the form of plates, which are connected together so as to form a strip that moves in a spiral and repeating in the upper part of the roll so as to form a winding surface for the webs.