The Fabrication of the Bullwinkle Platform

ABSTRACT The fabrication of the Bullwinkle Platform took place over a three year period from June, 1985 through May, 1988. This paper deals primarily with the fabrication of the massive 49,000 ton single piece jacket. The yard preparation, fabrication sequence, timing and the numerous innovative techniques utilized during, construction such as core block assembly of the center portion of the jacket, mounting cranes on top the jacket core to place infill members, major lifts performed primarily with winches, and extensive usage of computers during roll ups and load out are all highlighted. INTRODUCTION The Bullwinkle Platform consists of a 60-well slot, single piece jacket with two separate deck sections, located in the Gulf of Mexico on Green Canyon Block 65 in 1353 feet of water. An overview of the Bullwinkle project is presented by G. H. Sterling et al in Reference 1. The design of the platform is discussed by K. A Digre et al in Reference 2. Both are companion papers to this one. On June 6, 1985, Shell Offshore Inc. awarded a I contract for the fabrication, transportation and installation of the 49,000 tons single piece jacket to "Bullwinkle Constructors", a joint venture company formed by Peter Kiewit & Sons, Inc. and Gulf Marine Fabricators (GMF). At the time of award, there was not an established assembly site in which to perform the work. Bullwinkle Constructors (BC) expended approximately $20,000,000 building a bulkhead, dredging the waterfront, filling and grading the yard, installing piles and fabricating a concrete skidway system to accommodate the jacket. Considerable effort was expended from August 1985 to February 1986 assembling the necessary supplies and manpower. Fabrication of the jacket lilt Ingleside, Texas was successfully completed on schedule in May, 1988. FABRICATIONYARD The Ingleside yard is located on the north side of Corpus Christi Bay at Ingleside Point. It covers approximately 100 acres and is at the intersection of the Corpus Christi Ship Channel and the Intracoastal Waterway. At the time of award, the yard had an administrative building, maintenance shop, machine shop, wash rack and warehouse. To accommodate fabrication of the jacket, the site was improved and upgraded in many ways. Office space was expanded 5000 square feet and the parking lots were enlarged and fenced. Yard utilities were extended and placed underground. A liquid oxygen tank, three stationary air compressors, eight 480 volt electrical substations and a fuel gas system were installed. Additional yard space was also developed by using stabilizing cloth and limestone (Figure 1). Developing the new space took approximately six months and required 200,000 tons of fill. Dredging of the fabrication site slip was necessary to receive the large ships and barges required for this project. The dredging operation was divided into two phases.