In April 2012 Dormac Offshore staff began the refurbishment program of two consecutive Jack-up Rigs, a first for South Africa, in Saldanha Bay. The project entailed the re-activation of the old Mossgas site situated next to the present Saldanha iron ore and brake bulk terminals. The site, originally developed for the fabrication of top-sides, jackets, sub-sea structures, etc. for the offshore market, was well suited for this type of project. This site is also ideally suited for the refurbishment of offshore units with large lay down areas and extensive workshop facilities with 50ton overhead cranage, a blasting and coating booth and grillage facilities.
The first rig which arrived in late April was the Ben Avon a Marathon Le Tourneau Class 82-SD-C design built in 1980. The scope of works, to a large extent, concerned itself primarily with the rejuvenation of her pre-load and drill water tanks. The works included the staging up of all her internal tanks, high pressure washing, steel renewals, grit blasting the internal tank surfaces and the application of a full coating system. The preparation and coating of additional area’s included the cantilever and substructure, her entire hull, helideck and main decks.
Steel replacements were also integral to the success of the project where the majority of the works took place in the tanks as well as repairs on the all three of the leg K-Brace’s, in an elevated position. Significant piping renewals were also undertaken with installation of a completely new overboard main exhaust system and the renewal of sea water supply lines and fire lines.
The project was completed on time in just over 2 months and to the full satisfaction of the client’s high quality and safety standards.
A heavy lift vessel arrived with the second Jack-up rig, the Ben Rinnes secured on-board. After successfully floating off the Ben Rinnes, she was able to float on the Ben Avon and departed with on her delivery voyage to Mozambique.
The Ben Rinnes, a Le Tourneau Marathon Class 53 Enhanced 1973 built rig, had a much larger work scope, specifically in terms of steel renewals, which were on the critical path.
The steel renewals amounted to over 120 tons of internal and external plate work, which had to be methodically renewed as the rig was fully preload on its legs. Given this constrain and the restricted access, the steelwork was completed at a production rate in excess of 2.2 tons per day. This was a significant rate given that all of the steelwork was carried out in her drill-water and pre-load tanks.
The project’s other milestones included the high-pressure piping renewals and the total re-coating program of all external hull surfaces. In order to complete the re-coating of the hull external, the entire rig had to be shrink wrapped with special plastic to ensure 100% containment of all waste grit, water, paint, etc. Containment barges were used for access and waste collection in order to coat the underside of the two hulls.
Dormac Offshore was able to complete the entire refurbishment project for both Jack-ups within the tight contractual delivery program, whilst meeting and exceeding the stringent quality and safety standards set out by the client at the on-set of the project. Dormac achieved a zero lost time injury rate with in excess of 1,200,000 man-hours logged for the project.