Engine room safety

Engine room safety

Safety first

The maritime industry treats fire protection systems as a necessary expenditure rather than a means by which to safeguard valuable crew and cargo

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.

“This attitude feels in direct opposition to that in the aerospace sector, where if a fault occurs on an aircraft, that information is quickly and openly shared with airline operators, civil aviation authorities and engineering organisations. In shipping, unless a fatality occurs, it is left un-reported,” says Carl Hunter, CEO & MD of Coltraco Ultrasonics. With multiple ships sailing with partially-filled, over-filled or empty cylinders and many unshared instances of accidental discharges or slow seepages there is real cause for concern – and impetus to change.

Marine servicing

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 ships 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 abut 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,” Hunter informs.

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. Taking in to account the average time to record and validate readings, a service crew should take 1-3 minutes per properly-filled cylinder, which would mean 600-1,800 minutes test time or 10-30 perfect man-hours for this task alone. Again, this is impossible when allocated such a short time on the vessel.

Unsafe solutions

Given the time restrictions illustrated above, it is clear why even good marine servicing companies may not physically be able to perform the inspections required. While they may flag such an issue with a customer, there are less scrupulous companies that are said to randomly check some cylinders and then place ‘tested’ stickers on the rest.

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.

“These points are separate to the frankly dangerous actions of certain companies that may deliver systems portrayed and installed by contractors as NOVEC™ 1230 but that are actually filled with sand or water,” says the Coltraco head. Other anecdotal evidence provides stories of over/under-filled cylinders; high pressure gas systems being fitted without the means to actuate them; cheap cylinder pressure gauges sticking in position under humidity or mechanical fatigue; safety pins being retained in position in the cylinder valves after installation; or even pipework and cylinders that are freshly painted but have severe internal corrosion leading to particulates of rust which block the discharge nozzle mechanism.

There have even been reports of instances where bathroom weighing scales are chained to the CO2 cylinders in an effort to comply with IMO SOLAS FSS Code regulations – ignoring the fact that there are no officers or crew that are qualified to shutdown, dis-mantle, weigh and re-install a CO2 cylinder on the vessel itself.

Meeting obligations 

“Given both the crew lives and cargo at stake, it seems unfathomable that these systems are not permanently monitored rather certified just once a year, particularly since it is a regulatory obligation to ensure that crew are in a position to check these,” Hunter says. Safety of Life at Sea’s (SOLAS) International Fire Safety Systems (FSS) code states that “means shall be provided for the crew to safely check the quantity of the fire extinguishing medium in the containers”.

It can be argued that the existence of regulation (such as that set by the 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.

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 – especially when cost cutting may result in use of minimally-compliant gauge mechanisms.

Technological answers

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. This means that crew will be able to monitor the contents and then calculate the mass/weight of the liquefied extinguishant. By measuring the pressure of the gas on top of the liquefied extinguishant they can 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 the marine servicing company.

Ultrasound

One of the sciences being harnessed by innovators in the fire safety sector is that of Ultrasound: i.e. acoustic (sound) energy in the form of waves of high frequency that are above the human audible range. Although the shipping world merely uses it as a tool to gauge thickness, it has seen far more varied use across military, medical and industrial fields. 

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. 

Its portfolio boasts 11 different model types of Portalevel brand liquid level indicators including Portascanner (which uses ultrasound to test the integrity of confined spaces and can detect leak sites as small as 0.06mm) and Portagauge (which uses ultrasound to test the internal and external corrosion on pipework and cylinder wall thickness to an accuracy of +/-0.1mm). “We can monitor these 24/7 with the fixed, data-logging and autonomous monitoring system, Permalevel Multiplex & Permalevel Single Point,” says Hunter. “Signals from these fixed monitoring sites can be monitored centrally on the bridge and in the ship’s technical office concurrently. We see a day when products and systems will be designed that will monitor gas vapour above the liquid level and inert gases too.” The company is due to launch its Portasteele Calculator this year which will enable liquefied extinguishant weight conversions.

“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,” he adds.

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