Survitec tests fire extinguishing systems aboard three FPSOs

By Ariana Hurtado, Editor and Director of Special Reports

ENGLAND — Earlier this month, Survitec released the results of tests conducted on high-pressure CO₂ fire extinguishing systems aboard three FPSO vessels.

The UK-based company is a manufacturer and supplier of survival equipment, such as life rafts, marine evacuation systems and offshore rental PPE, and also a provider of fire solutions to the maritime industry.

According to Survitec, the full-release tests are believed to be the first to be conducted on vessels of this type and of such protected volume, and they confirmed the value to shipyards and ship operators of live testing to verify on-paper or on-screen predictions of fire system performance.

Survitec verified the performance of CO2 fire extinguishing systems by recreating the demands of an actual fire.

“The CO₂ fire extinguishment system demonstrates remarkable efficiency in tackling challenging fires," Michal Sadzynski, product manager of water mist systems with Survitec, told Offshore. "As delineated in pertinent literature, the operational efficacy of this gas-based mechanism necessitates the meticulous sealing of protected spaces, complemented by the installation of overpressure relief devices. Any malfunction in these components may precipitate a systemic failure, leading to potentially catastrophic outcomes. The deployment of a total flooding system in response to a fire event incurs a financial burden for maritime entities; however, this expense pales in comparison to the potential loss of an entire vessel."

He continued, "Within the offshore energy sector, characterized by sizable vessels, diverse transported mediums and heightened environmental ramifications, the significance of safety test protocols is magnified. Consequently, rigorous testing procedures validating extinguishing effectiveness assume paramount importance in mitigating the inherent risks and safeguarding both personnel and assets in the offshore industry.”

Testing results

The protected spaces did not pass the tests the first time. This suggests there may be other vessels and offshore structures out there with potentially underperforming CO₂ fire extinguishing systems in fire-critical areas such as switchboard rooms, engine rooms and generator houses.

The initial tests on the three FPSOs were conducted in a variety of scenarios and vessel operations from moored in the oil field to within the shipyard delivering the conversion.

“The devised live test comes as close as is practical to creating the demands of an actual fire aboard. On large vessels like FPSOs, it involves opening hundreds of cylinders – for example, in the engine room of one of these FPSOs, 315 cylinders were released,” Sadzyński stated in a company news release. “We have found that the release of large amounts of highly pressurized gas into a partially closed space usually uncovers some engineering challenges within the protected space, rather than with the delivery system itself.”

In the switchboard room test aboard the first FPSO to be tested, the space was gas-tight due to the unrelated system requirements for the air conditioning system.

During the live test, the rapid pressure increases in the space found the weakest point, which in this case was the door, causing damage. This damage reduced the gas integrity of the space, allowing CO₂ gas to escape, leading to test failure.

On the second FPSO, another key finding was that a machinery space or compartment cannot always be assumed to be airtight. In one test, the gas collecting inside the space started to escape through leaks, leading to a drop in concentration and test failure.

Survitec's Michał Sadzyński said, 'It is important to emphasize that designing a vessel is a highly complex process, encompassing hull structure, compartment layouts, ventilation systems and so on, which all interlink with the design of the fire suppression systems. As the build progresses, any amendments or deviations that are introduced can have unforeseen consequences that impact system performance – the most critical being the failure of a fire extinguishing system during emergency firefighting operations. This study shows very clearly the limitations of modelling the performance of a fire suppression system within a virtual environment at the vessel design stage versus a real-world test.” — Survitec's Michał Sadzyński said, "It is important to emphasize that designing a vessel is a highly complex process, encompassing hull structure, compartment layouts, ventilation systems and so on, which all interlink with the design of the fire suppression systems. As the build progresses, any amendments or deviations that are introduced can have unforeseen consequences that impact system performance – the most critical being the failure of a fire extinguishing system during emergency firefighting operations. This study shows very clearly the limitations of modelling the performance of a fire suppression system within a virtual environment at the vessel design stage versus a real-world test.”

Solutions, costs

“There are often relatively simple and inexpensive fixes in these scenarios,” Sadzyński explained. “Overpressure in air-conditioned spaces can be resolved by implementing a time delay on one of the fire dampers. This allows over-pressurized gas to escape from the space and then closes when the pressure becomes stable, thereby keeping the CO₂ concentration at the required level. This was the solution for the switchboard room on the first vessel to be tested.”

There are expenses associated with full-release testing, as the CO₂ cylinders are completely exhausted in the test and require replacement to recharge the system. Additionally, CO₂ is not a human-friendly gas, so if the vessel is in operation, all personnel or crew need to be relocated to a safe space. However, Sadzyński noted that the consequence of operating a system that fails to perform in a real-world scenario could be catastrophic.

Survitec's aim is to convey the benefits of conducting tests on gas-based systems to enhance safety rather than being viewed as a procedural requirement.

12.07.2023