Fire risks for ships with retrofitted scrubbers, warns Survitec

Shipowners need to upgrade their firefighting systems when they install a scrubber. Credit: Survitec

Safety survival and solutions provider Survitec has issued a warning to shipowners, urging them to verify the capacity of their fixed firefighting systems before undertaking any scrubber retrofit projects. 

Many shipowners are retrofitting marine exhaust gas cleaning systems as a way of complying with the sulphur cap regulations that entered into force on January 2020, which mandate the use of fuels with a sulphur content of less than 0.5% mass by mass. The use of scrubber technology allows shipowners to continue using heavy-fuel oil with a high-sulphur content because the scrubber system scrubs the sulphur from the exhaust gas.  

While amendments to MARPOL Annex VI covering the sulphur cap regulations do not specifically require additional firefighting capability, Survitec is reminding shipowners that any increase in machinery space size will require an increase in fire-extinguishing capacity. Therefore, it is recommended that shipowners evaluate and, if required, upgrade their firefighting system capacity when they install a scrubber. 

Dagfinn Aasdirector, technical management, Survitec Fire Solutions, said, “A scrubber installation often requires extending the engine room in the casing area, and when the engine room’s volume is increased the capacity of the extinguishing agent – in most cases CO2 [carbon dioxide] – must also be increased.

“When volume is increased, the system needs to be recalculated and re-engineered with additional CO2 cylinders and additional nozzles. New flow calculations need to be carried out to verify the new system will discharge the correct amount of gas within the required two minutes. Drawings must also be sent to the classification society for approval before installation can take place. This means some installations may have to be removed and reinstalled,” continued Aas. 

For example, if a scrubber is installed in a totally separate space, with a bulkhead facing towards the engine room, then there is no need for an additional firefighting system, said Survitec. However, in other cases, additional nozzles will have to be connected to the existing pipework covering the scrubber area, or additional CO2 cylinders may be required. Survitec warns that it has also witnessed scrubber retrofits that have required completely new firefighting systems.  

In the run up to the 1 January 2020 implementation date, Survitec reported that it registered a significant increase in fire system retrofits.  

Michal Peruga, operations director, Survitec Fire Solutions, said, “We are seeing a number of inquiries where shipowners have left it too late and have realised the need for CO2 upgrades only when classification surveyors begin certifying the scrubber installationInquiries are coming in just one or two months before the drydocking, which is far too late. This can result in delays to the vessel re-entering service and unbudgeted drydocking costs.”