Picture of BMT designed tug at sunset

Marine simulation for Shell’s Appomattox Platform (USA)

Before installation, Shell’s Appomattox Floating Platform was wet-towed for 130 km from the integration yard to the installation site. BMT provided marine simulation studies to enable safe towage operations and navigation.

28 December 2018

Commercial Maritime

Heerema Marine Contractors (HMC) hired BMT to provide marine simulation studies to support installing Appomattox Floating Production System - Shell’s largest floating platform in the Gulf of Mexico. The topside and hull of Appomattox were integrated at Kiewit Offshore Services, Ingleside, Texas, before installation. The completed platform was then wet-towed from the integration yard to the installation site. One of the most significant risks associated with this tow was the inshore tow from the integration yard to the sea buoy at the end of the Aransas Pass.  The departure through the La Quinta and Corpus Christi ship channels presented challenging manoeuvring, control and navigation issues. 

To facilitate this operation, BMT delivered a multi-user training simulator to enable HMC to investigate towage operation obstacles and manoeuvring characteristics of the hull during the coastal part of the tow, covering La Quinta, Corpus Christi Ship Channel and Aransas Pass.  These studies played an integral role in identifying overall obstacles during the towage operation and developing operating strategies. Furthermore, the studies helped to determine rational weather and tidal operating limits and provide training and familiarisation for the towmasters, tug captains, pilots and other marine personnel who were involved in the tow.

Mumanthi Mvuria, a Specialist Engineer at HMC, says:

“This preparation work was a critical part of the planning phase and as such, resulted in the safe arrival of the system to its destination in the Gulf of Mexico.”

There were several phases to the simulation studies. Firstly, we developed Computational Fluid Dynamics (CFD) calculations to determine the hydrodynamic and propulsion properties of the platform and the close-coupled tugs.  Once those CFD calculations were in place, physical model testing of the platform and close-coupled tugs in a shallow water basin were carried out to confirm the results of the CFD analysis. BMT further developed a hydraulic simulation of the tidal and non-tidal current flow through the Corpus Christi channels, which provided a time series of the currents likely to be encountered during the tow.  The final phase was delivering the training simulator suite to the customer’s site in Texas and constructing simulation models of the tow using BMT’s industry-leading navigation simulator, REMBRANDT, which incorporated the tow handling and environmental models developed in the preceding stages.


Image courtesy of Mark Wilson - used with permission

Share this

Related articles