Patent ID: 7985036

Claim:
A method of towing an underwater pipeline by head tugs for pulling and tail tugs for counter-pulling, the method comprising: connecting a set of equipment to the pipeline itself, the equipment including floats, at least a float of the floats has an at least partially variable buoyancy, the floats placed in pre-established positions and at pre-established intervals to provide a graded buoyancy to the pipeline based on a distance from a seabed so as to obtain a festoon configuration of the pipeline by providing suspended sections of the pipeline, in correspondence with the floats, alternating with resting sections of the pipeline; and adjusting the graded buoyancy provided to the pipeline based on the distance from the seabed, including establishing a threshold height, measured from the seabed, of said float having an at least partially variable buoyancy and maintaining the threshold height by automatically adjusting the buoyancy of said float in response to the distance of the pipe from the seabed.