Installation of cables in an array of ducts

Method for installing a cable in a duct network comprising a remote duct, the method comprising:

• a first phase with at least the steps of:
• introducing the cable into a first duct having a first size such as a first diameter,
• introducing at least one first pig into the first duct, said first pig being arranged to couple with the cable,
• introducing a liquid at first pressure and first flow into the first duct, for transporting the cable equipped with the first pig through the first duct,
• stopping the cable when, or after, its foremost end has reached an exit of the first duct,
• a second phase with at least the steps of:
• attaching at least a second pig to the cable and introducing the second pig into a second duct, being the remote duct, and having a second size such as a second diameter, different from the first size,
• introducing again a liquid at first pressure and first flow into the first duct,
• introducing the liquid at second pressure and second flow into the second duct, for transporting the cable equipped with the second pig through the second duct,
• compensating, until the first pig reaches the exit of the first duct, at a location between the first duct and second duct, for a difference in flow or volume of liquid,
• wherein the difference in flow or volume is caused by the first pig travelling in first duct with same speed as the second pig travelling in second duct, while the first pig is still in the first duct.