The AH001 stays afloat with a little help from the marine management system impletmented by ISS

As a result of legislative changes Amerada Hess had a requirement to modernise its Marine Management System (MMS) on one of its offshore oilrigs.

This was no simple system update – The MMS is a safety critical system responsible for monitoring onboard systems.

The system philosophy was to replace the existing MIMIC panel arrangement with a distributed control network providing improved functionality, ease of use and limitation of the effect of single point failures.

Whilst implementing the new legal requirements Amerada Hess also wanted ISS to design the system to comply with relevant industry standards and employ proprietary network hardware and custom written operating software.

After careful examinations of the architecture of the old system, Mitsubishi Electric MELSEC Q Series PLC's were chosen as the controllers in addition to MX2000 SCADA for the operator interface. The installed PLC / SCADA network consists of 4 MX2000 SCADA Nodes, 9 Mitsubishi Q Series PLC’s, a Fibre Loop network, an Ethernet network and CC Link networks.

The fibre network allowed all SCADA related command signals to be distributed to the appropriate PLC and allowed for the Remote I/O status to be collated and transferred back to the SCADA for display. The network was configured with dual loops to allow for redundancy under failure conditions of one loop.

The ISS scope of supply for the project included the following:

• System Design
• PLC / SCADA Software
• Offshore Commissioning

Several Benefits of the new control system have become immediately apparent to plant engineers and operators. These include:

• Increase fault diagnostic features
• Increased system reliability
• Improved control over the whole system
• Easy to use screens that produce less mistakes
• Improved data collection for use in reports

These advantages have helped confirm that ISS were the right decision for Amerada Hess.

The MMS monitors all aspects of platform stability from ballast tanks to the mooring system