Design & Analysis
Design & analysis services together with engineering software have formed the back-bone of our business. The Irish Sea Pioneer was designed by STA in the 90’s and continues to operate in the Celtic Sea. It is a self-propelled jack-up with design optimized for working with unmanned gas production platforms. STA has specialized in liftboat and jack-up analysis.
The hull was built by Bollinger Shipyards in LA and the legs and jacking units were built by LeTourneau in TX.
A modified design with 750t crane is the “Irish Sea Pioneer Mk2” shown below.
OOSLFP – Open Ocean Stabilized Live Fire Platform for Missile Testing, for US Air Force. This is a 5-acre floating concrete structure designed for permanent operations, moored in the Gulf of Mexico, off Florida. STA provided the basic design concept and concrete hull global analysis and optimization for hydrodynamic response to Cat-5 hurricane conditions. A 24-leg semi-taught polyester mooring system was designed. Mooring analysis was performed in the time domain using both AQWA and OrcaFlex. PCCI performed model tests at Escondido.
MOPU – MALEO PRODUCER – Indonesia. The Maleo Producer is a converted mat-supported jack-up for gas production. It is located in a seismically sensitive area and required extensive design and analysis efforts in order to obtain ABS certification. A significant geotechnical site investigation effort was undertaken, partly from the platform, after jacking up on location.
A Roson was deployed from the installed platform and modified support framing and rigging was arranged to enable sampling right up to the edge of the mat and inside the mat cut out areas.
Classical geotechnical analysis was supplemented by full scale measurement of ground disturbance.
A Special Session at the Offshore Technology Conference was dedicated to the Maleo Project in 2008. Some of the papers were authored and co-authored by Bil Stewart. This OTC session would not have been possible without the author’s help from many talented and exceptional engineers including, Paul Jacob and Ahmed Nisar from MMI Engineering, Jack Templeton from Sage USA, Alan Young, Don Murff and Dan Spikula from GEMS,Inc, Jean Audibert from Quest Geo-Technics, Steve Neubecker from AdvancedGeomechanics, Vladimir Rapoport, Consultant. The ABS team included Bob Pyke, Consultant, Paul Thenhause from ABS Group, John Stiff and Robert Sheppard fromABS Group, Houston, and Yatendra Rajapaska, ABS, Houston. Special thanks are given to the Maleo Producer OIMs, especially Mike Ward, and to GPS Indonesian Manager, MarkO’Connor, who both helped enormously with the Fugro personnel and equipment onboard during the local site investigation around the mat. Santos is thanked for permission to publish papers in this special OTC session.
PLEM Design for NAVFAC, Okinawa. STA provided detailed design and specifications, fabrication and installation assistance.
STA uses in-house software developed largely by Bil Stewart for many design problems in mooring and pipe laying. Some programs, like STA PILE3, for suction embedded or driven anchor piles, are made commercially available.