Co-at marine


The ENSCO100 Drilling Rig was being refurbished and co-at marine were tasked to install the HVAC and HVAC Control System for the Accommodation Module. Initially ENSCO had specified the requirement for inverter speed control on various fans such as AHU Supply, Galley Extract, Smoking Room Extract, Toilet Extract etc and Three-Stage Thyristor Control for the AHU PRE-Heaters and Re-Heaters

The Solution:
Simonswood Automation initially provided a solution by installing an Allen Bradley CompactLogix PLC Control based system incorporating Allen Bradley PowerFlex 40 and PowerFlex 70 inverter Drives for the Fans and Eurotherm 7300S Thyristor Controllers for the Pre-Heater and Re-Heater Control. This was initially commissioned and tested during the rig refurbishment at the shipyard in Poland and functioned correctly, but once the rig was operational and the Drill was running, the excessive voltage spikes, 600-700V, from the old generator (which was not replaced in the refurbishment) damaged the electronics in the inverters and Thyristors which were unable to function as required. The Simonswood Automation team of Engineers (with BOSIET Offshore Survival Training) flew out to the Drilling Rig in the North Sea and modified the control panel by installing conventional DOL Starters with Thermal Overloads for all Fans and Conventional 3 Stage Contactors for the Pre-Heaters and Re-Heaters. The PLC software was also re-programmed to facilitate the revised requirements


The Result:
The Heating and Ventilation on the Accommodation Module of the ENSCO100 Drilling Rig is functioning satisfactorily with all fans and heaters maintaining the required temperature and flow of air for the comfort of all the shift workers

“As part of our remit, we were required to provide a fully automated system that controlled and monitored all fans, heaters, chilled water plants and pumps needed to serve a new 100 man accommodation block on board a drilling rig under refurbishment in Poland. The client’s remit was brief, the timescale was tight and space to house any panel was at a premium.

Simonswood provided a detailed design that met all the client’s requirements and subsequently built the control panel to meet the time scale and available space. They then provided highly knowledgeable commissioning engineers to commission the control system in Poland and in a timescale that enabled us as the HVAC contractor to hand over the completed system and enable the crew to move on board.

We would have no hesitation in using Simonswood again and indeed they continue to support us in providing solutions to the marine and offshore HVAC industries”

Ken Maciver, Director, co-at marine Limited