Break in the Bahamas
Category: Bridges & Structures
Method(s): Wire Sawing, Concrete Wire Sawing
Location: Grand Bahama Island in Freeport, Bahamas
A large pier at a busy oil terminal in the Caribbean was struck by a tanker, causing severe damage to the structure. Part of the pier’s dolphin platform was left protruding approximately 5 feet from the water while the rest had sunk below the surface. Three months later, the situation worsened when Hurricane Isaac blew through and caused the entire pier to sink around 6 feet below water level. Millions of dollars were being lost while the pier was not in use, so it was important the owner quickly removed and replaced it. In addition, the structure had become much harder to spot by passing ships, making it more susceptible to collisions.
Break in the Bahamas
The submerged pier was unstable and the bottom sat approximately 30 feet below the surface of the water. The top of the section would break the surface during low tide and be around 6 feet below the surface during high tide. The damaged section consisted of a 1.5-inch-thick steel plate measuring 25 feet by 25 feet. The plate needed to be cut into three sections for a barge-mounted crane to lift it from the water and place on a work platform for disposal. The plate was connected to six 3-foot-high I beams, so cuts had to be made through each one to free the sections.
A diving vessel with six divers and two crew members from Orion Marine was employed to support the work of the joint venture. Each day consisted of a 20-minute boat ride to the pier, where a work platform and crane barge were anchored in place. A modified WS25 wire saw from Diamond Products was positioned on the work platform, standing 25 feet above the water. Divers entered the water and captured video to allow ABC/In-Place Machining Company to assess the situation and create a game plan for the cutting work. Instructions were then given to the divers for the installation of the underwater pulleys, while the cutting team set up pulley stands on the work platform. Custom-fitted fenders were attached to some pulleys to prevent the wire from ‘jumping’ off while cutting underwater.
Joe Bland was ABC’s project manager for the BROCO job. “We selected In-Place Machining Company to take the lead on this project due to their vast underwater wire sawing experience, which worked out extremely well for everyone involved. More importantly, there was a mutual trust and respect between the two companies. This insured the project was completed in a timely fashion, to the best of our abilities and to the satisfaction of the customer.”