Weighted island for industrial operations at sea - having a heavy base made of horizontal tubular bodies and watertight columns secured to base

A ballasted island for installations at sea comprises a heavy base construction intended to rest on the seabed and having watertight compartments making it buoyant, a number of hollow watertight columns secured to the base and stretching upwards, a bridge also able to float, designed with an integral platform for carrying the equipment, and openings for sliding along the columns with lifting gear enabling the base and the columns to be lowered gradually into the water. The base is formed from a number of horizontal tubular bodies and is triangular, rectangular or circular in shape. The tubular bodies have watertight bulkheads dividing them into separate compartments and they form a whoel with a padstone surrounded by a perforated wall and braceed with stiffners. At points on the base there are vertical circular shafts for attachments for the columns together with possibly provision for piles. 30-50% less concrete required for the pillars and water forms a satisfactory ballast. Can be constructed in shallow water close to land where the heaviest pieces can be assembled and towed to site at a depth 50-70% less than that required for conventional rigs.