Addressing Outdated Engine Room Safety
The maritime industry treats fire protection systems as a necessary expenditure rather than a means by which to safeguard valuable crew and cargo, writes Dr Carl Stephen Patrick Hunter.
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.
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 per cent of a ship’s CO2 cylinders have discharged or partially leaked their contents at some point in their lifetime.
This makes high quality servicing particularly important, which requires not just a company that is properly resourced (rather than simply the lowest bidder) but also an appropriate amount of time. In many cases, marine servicing contractors often have to get to the ship using a launch and only have access to the vessel for about four hours. If using the historical method of servicing the vessel’s fire system, the service crews would shut down the ship’s CO2 system, dismantle it and weigh each cylinder. This takes about 40 minutes to dismantle, weigh, record and re-install, meaning that it would take 400 man-hours to achieve on a 600 cylinder marine installation – completely impossible in a four hour visit.
Luckily modern methods offer quicker options: a portable, ultrasonic liquid level indicator (such as Coltraco’s Portalevel MAX Marine) can check the contents of a perfect condition cylinder in 30 seconds.
Given these time restrictions, it is clear why even good marine servicing companies may not physically be able to perform the inspections required. 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.
Given both the crew lives and cargo at stake, it seems unfathomable that these systems are not permanently monitored rather than certified just once a year, particularly since it is a regulatory obligation to ensure that crew are in a position to check these.
It can be argued 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.
The fact of the matter is that technologies exist right now that can easily and accurately monitor everything from gases under pressure to liquefied contents and corrosion of pipework. The traditional method of using a cylinder pressure gauge (located at the meeting point of valve and neck of a pressurised cylinder) is both obsolete and impractical.
Technologies will soon exist that will offer devices that monitor both liquid content and gas pressure safely from the external sides of the cylinder rather than within it. By measuring the pressure of the gas on top of the liquefied extinguishant crews can assess the pressure of an inert gas (which is in an entirely vaporous form) to ensure that the cylinder is primed to perform when needed.
Having systems that operate transparently will work not just to convince a vessel owner that his asset is in good hands, but also to reassure the crew that their safety is taken seriously by both – their employer and the marine servicing company.
Ultrasound is also one of the sciences being harnessed by innovators in the fire safety sector; acoustic (sound) energy in the form of waves of high frequency that are above the human audible range. Sound is, in itself, vibrations that propagate
as a mechanical wave or pressure and transmit through solid, liquid or gaseous mediums. Coltraco is one 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.
As the world changes, so must our industry integrate technological solutions to provide a bulwark against wider industry misinterpretation and minimal, even occasional and flagrant, disregard in the application of standards and good global engineering practise, creating standards which all can understand and apply.