The accommodation platform needed to be moved from its location off Veracruz, Mexico to dry dock in Holland. It had four retractable legs that were weighted down on the seabed by large triangular footing extensions to the spud cans. These were attached to the end of the legs and secured them tothe sea bed. Unfortunately, with all four of the extensions attached, the platform would not fit over the width of the carrier vessel. It was necessary for two of these extensions to be removed, work which was assigned to Hydrex.

The triangular footing extensions were quite large at approximately 55 tons each and measured 7m by 7m by 7m in size. They were secured to the legs by large locking pins whichhad to be removed. The platform was based in water at a depth of 17m and the original plan, when the job was agreed upon, was to move the platform to shallower water. However, due to port regulations the authorities forbade the repositioning of the platform to water of this depth and it had to be moved to another 17m deep location where the work could take place.

The point of moving into shallow water was that the legs could be fully rested on the sea bed and therefore the weight of the extensions would be taken off the locking pins, making it easier to remove them. As this was not possible, the legs were retracted to a depth of 8m below sea level and a method was worked out by the diving team, emptying the ballast tanks of the footing extensions and using a block and tackle system, to take the weight off the triangular extensions so that the locking pins could be removed. Whilst the unpredicted work in deeper water required extra time, the diving team worked flat out to get it completed before the carrier vessel arrived.

Once the pins were removed the legs were positioned on the seabed, the block and tackle system removed and the legs were then fully retracted without the footing extensions, which were to be recovered at a later point. The platform was loaded onto the carrier vessel on time, sailing off to dry dock to be repaired on schedule.

MJ Information No: 21224