Tanker operators are being urged to verify the contents of CO2 fire-fighting systems between annual certification checks by testing cylinders in situ without disturbing them
One relatively overlooked area of marine gas detection relates to the leaking of CO2 and other gases used in onboard fire-fighting systems. UK-based Coltraco Ultrasonics believes that methods currently being used to ensure the integrity of the contents of such systems on board tankers, and the air and watertight seals on the compartments and enginerooms where they are contained, are deficient in a number of respects. Consequently, Coltraco argues that greater use should be made of ultrasonic measuring technology to ensure the safety of vessels and their crews.
The company suggests that the potential risks posed to crew by the escape of pressurised gases used to fight fires on tankers are not fully understood. Moreover, the leaking of gas can impair the ability to fight a fire should one occur because the concentration required to extinguish the fire is dependent on there being a sufficient quantity of the extinguishing agent, as well as the ability of the engineroom or compartment to contain the agent once it is actuated.
Coltraco chief executive Carl Stephen Patrick Hunter explained “IMO SOLAS FSS Chapter 5 regulations impose a duty on the operator to monitor onboard fire-fighting pressurised gases for content. We are deeply concerned that many companies are now relying on an annual certification check to fulfil this. In recent times there have been a number of incidents of fires on board vessels that suggest at the point of the fire breaking out, gas was not there in sufficient quantities to extinguish it. So something is clearly going wrong.”
Rather than rely on an annual ‘MOT’-type assessment, Coltraco believes that operators need to ensure that the content of pressurised gases in fire-fighting systems on tankers is more regularly and accurately checked by crew while the ship is at sea.
Mr Hunter said that the technology is already available “to allow crews to check in situ without disturbing the system or having to move around large, heavy containers. Ultrasonic sensors can safely, quickly and accurately measure gas content and detect any leakage, and in a way that is more easily manageable for tanker crews (taking on average only 30 seconds a cylinder).” The company suggests its latest-generation portable liquid-level indicator, Portalevel Max Marine, is particularly well suited for this checking operation. Ultrasonic systems such as Coltraco’s Portascanner technology can be used to assess the room integrity of the spaces where the fire-fighting systems are located.
Mr Hunter added “Testing the liquified gaseous extinguishing systems and the integrity of the room in which they are situated creates a holistic approach to solving the problem of managing what is, in many respects, an ungoverned space at sea.”
There is, Coltraco suggests, growing recognition of the benefits of using ultrasonic technology to check fire-fighting gases. The biggest success to date has been the decision of Carnival Cruises to install the Portalevel Max Marine system on board all its vessels to test the CO2 fire cylinders for leaks in content.
The Portalevel Max Marine system is designed to allow a vessel’s crew to inspect large fire-fighting systems incorporating up to 600 cylinders. Mr Hunter explained that “the ease of operation, in comparison with weighing, increases the ability to carry out more regular and frequent checks, improving fire-safety management on board. Using Portalevel allows one person to carry out a check in less than 30 seconds, rather than two people laboriously weighing in around 15 minutes.”
Coltraco is continually upgrading the ultrasonic testing systems it offers, and has recently developed the new Portalevel Intrinsically Safe portable liquid-level indicator. This unit is designed for testing pressurised fire-fighting gas cylinders on board gas carriers in Zone 1 areas. The company is the first to gain ISO/IEC 80079-34 standard approval to supply ultrasonic testing systems for monitoring on LNG and LPG carriers at sea, or in Zone 1 areas in terminals ashore. Production of the new unit is expected to start shortly, with the first deliveries anticipated in mid-2018.