In terms of ships’ extinguishing systems there exist two broad categories: sprinkler systems and gas systems (CO2). While the former can suffer leakage but the latter can cause catastrophic effect given the high physical pressures. An average ship’s CO2 system comprises between 200 and 600 cylinders each containing 45KG of CO2 under high 720 psi/ 49 bar pressure. One of the highest probabilities of discharge occurs during their maintenance. Some marine service companies estimate that 20% of a ship’s CO2 cylinders have discharged or partially leaked their contents at some point in their lifetime.
Although random checks may be suitable in some sectors, it is worth remembering that because the normal design concentration of CO2 of 34-72-v/v % is above the nearly immediate acute lethality level, these systems have an extremely narrow safety margin. As these systems work through oxygen dilution rather than the chemical disruption of the catalytic combustion chain (which is the case with other clean agents), insufficient CO2 levels during an emergency may allow a situation to spiral out of hand. Gaseous extinguishing systems protect urgently important infrastructure against special hazards, fundamental for the safeguarding of critical facilities. Yet, because gaseous extinguishing systems are highly pressurized, the risk of leaking and discharging is accepted as part of their use and this is shown in the regulations that demand their upkeep so it is always recommended to possess ultrasonic level indicator onboard.
Moreover, with fewer, even lower-skilled crew and greater dependence on autonomous machinery, the dependence on fire systems being checked from shore, let alone on the ship in person, will only become greater. Manual weighing is not only laborious, but also dangerous to the crew conducting the servicing. Numerous accounts of incidents have been reported related to manual weighing, but two of the most significant are the injury to 22 US Marines when a Halon-containing fire extinguisher went off in 2015, California and the death of 20 people in an accident on a Russian nuclear submarine when a Halon extinguishing system was activated by mistake.
Without the means to manually check and with the threat to the crew, constant and remote monitoring becomes vital. It can be argued that the existence of regulation (such as that set by the IMO and other authorities) guides – and occasionally curbs – the direction taken by the free market. This then means that the current state of the market, where ‘price is king’ is either due to unwillingness on the part of the regulators to create an environment where safe engineering is rewarded or because the industry itself is unaware of new technology that will help them meet both the spirit and letter of the regulation.
Cost Cutting, Lack of Experience and Increasing Risks
Although the value of the marine assets that fire systems protect is increasing rapidly, the competitiveness of the free market places great pressure on cost cutting. Often, cheap systems only minimally comply with the regulations and, in fact, there are very few qualified engineers who may be considered experts on the subject matter. This creates an environment in which a ‘safety first’ culture remains both un-pursued and unrewarded.
Routine maintenance is liable to be overlooked because it is difficult and the crew unqualified to test or given insufficient attention by the owner of the system. The neglect of continuous monitoring of the fundamental protection provided by the gaseous extinguishing systems is to the peril of the lives of occupants of the ship and at the risk of crippling financial and reputational loss to the tanker owner. It is usually the case of systems like these that they are out of sight and out of mind, and they are often located in some plant room, which only the maintenance contractor visits, if at all. The most modern technology is integration of ultrasonic technology in monitoring devices.
Operating Method of Ultrasonic Technology
Sound is, in itself, vibrations that propagate as a mechanical wave or pressure and transmit through solid, liquid or gaseous mediums. Coltraco is one out of a number of companies using these fundamental physical principles to design and manufacture products and systems that can be used by fire engineers and their customer installations. It has a huge range of products, which are all integrated with ultrasonic technology such as ultrasonic liquid gas level indicator. Ultrasound is merely sound beyond our audible range. Dolphins and whales can communicate at sea over long ranges as sound travels more efficiently through liquids than air. We use this principle to identify that difference in a cylinder containing liquefied agent. Consider one’s ears as “the receiver” and one’s mouth as the “transmitter”. Sound will arrive at the ears at different times. The reason though that we hear a unitary sound is that our brain processes it to one. This is what we do by processing the returning ultrasound. In the air bats navigate by airborne ultrasound. We can do the same for contents and room integrity monitoring in the fire industry.
In terms of contents monitoring of single walled fire suppression cylinders in the fire industry, a sensor is utilized as a transceiver to transmit ultrasonic pulse through the walls of the cylinder and to analyze the strength of the returned signal that determines the level of contents. As sound behaves differently in air and liquid, so will the strength of the returned signal be different in the liquid and air allowing us to identify the level of contents accurately.
To make any inquiry, please contact Coltraco Customer Service.