Page 26: of Maritime Reporter Magazine (April 2011)

26 Maritime Reporter & Engineering News

CASE STUDY DOCKWISE

Dockwise has been providing world- wide transport solutions for more than 30 years and its vision is to become the con- tractor of choice throughout the Heavy

Marine Transport (HMT), Transport &

Installation (T&I), and Logistical Man- agement services industry. Founded in 1959, Swecomex has provided process equipment for hundreds of plants world- wide, as well as been actively involved in both offshore fabrication and interna- tional offshore and onshore projects.

In 2010, Dockwise was awarded the contract for the Swecomex Independen- cia I, the first jack-up rig ever constructed in Mexico. The scope of work for Dock- wise included the opportunity to con- ceive, engineer, manage, and execute this historic operation. As part of the Dock- wise Group of Companies, Ocean Dy- namics (ODL) is an engineering consulting company headquartered in

Houston, Texas. Providing engineering and consulting services to the offshore in- dustry, ODL specializes in the analysis and design of various offshore structures (fixed and floating), marine analysis and design, mooring systems, and offshore transportation and installation.

The combination of ODL’s engineering expertise, along with the project man- agement experience within Dockwise, re- sulted in the load out of the Swecomex

Independencia I jack-up rig being the first project to be entirely engineered and managed out of the Dockwise Houston office. The Dockwise scope of work for the Swecomex project included the load out of the Independencia I jack-up rig from the Swecomex fabrication yard into the Tuxpan River, directly in front of the

Swecomex dock. Although a Dockwise vessel would have been preferred, the load-out location introduced depth re- strictions that prevented the use of any vessel from the Dockwise fleet. There- fore, the load-out concept turned out not to be a simple one.

After various scenarios were consid- ered, the relocation of the rig was ulti- mately accomplished by loading out the jack-up transversely onto a 100-ft wide barge, rotating the assembly, and lower- ing each jack-up support leg on either side of the barge so that the rig would stand on its own. Finally, the barge was removed from the narrow space under the rig while avoiding any contact with the jack-up support legs.

With an invaluable opportunity to enter into the offshore market in Mexico,

Dockwise contracted a powerhouse team to safely and successfully execute the details of the operation. The heavy moving expertise of Mammoet was brought in to perform the skid-on and load out of the rig, while Crowley pro- vided the ballast engineers as well as a barge that met all the size and strength requirements for the operation. SAAM

Tugs, RK Consultants, Port Captains, and Port Authority of Tuxpan provided their expertise in executing the stabil- ity-critical rotation of the barge and rig.

The project was not short of potential complications. Many management and engineering hours were spent decipher- ing and designing all the details of the op- eration to ensure a safe and successful load out. Beginning with the transverse load out of the 11,200 ton rig onto a 100- ft wide barge, where ODL strength cal- culations showed use of nearly all the capacity of the barge, to rotating the barge and rig together 180 degrees, which challenged all stability guidelines.

These issues were mitigated with inno- vative engineering and design, which provided strengthening measures for the barge with a skid beam design that al- lowed the loads to be spread safely. An evaluation of the stability of the rotation maneuver resulted in draft and vertical center of gravity limitations that were then communicated to the client for the jack-up hull.

During the operation, a constant col- laboration with the client and the sub- contracted parties was paramount to

Engineering Ingenuity Helps

Ensure Success of Swecomex Project

By Robb Erickson, Vice President Sales, Heavy Marine Transport Worldwide, Dockwise