The devastating potential of a fire at sea means that modern cruise liners are bristling with fire protection systems, often beyond international requirements. Olaf Roschninski and Bernd Eilitz explain.
There has been growth in fire safety engineering measures on board cruise liners which is almost unparalleled in any other sector. The luxury cruise ship business is fiercely competitive and the cruise lines therefore take many precautionary measures to prevent accidents on board, which would not only threaten the millions of pounds’ worth of investments in the lavishly built ships, but would also cause severe damage to their image.
Many of them invest much more in fire protection measures than they are required to under international regulations. In the past few years, Minimax has fitted out several luxury cruise ships with modern extinguishing technology. Now the company has even developed a system that efficiently contains the long underestimated danger of balcony fires.
At high sea, ships must be self-sufficient. When fighting a fire, outside help cannot be counted on and fast evacuation is usually impossible. Only the extinguishing technology located on board the ship can prevent disruption, injury or death. The fire catastrophe on board the Star Princess in March alarmed the entire cruise line industry. The incident, in which one passenger died and eleven others suffered from smoke inhalation, abruptly uncovered a huge vulnerability in the fire protection plans of modern passenger ships. The economic consequence was that this relatively new ocean giant was out of commission for more than six weeks. The damage to customer loyalty is harder to estimate.
First class protection
So prevention also seems necessary from an economic point of view. Many companies are particularly careful to fit their fleets or to upgrade their ships with the latest fire protection solutions.
For years, Minimax has been testing and developing such solutions. Almost all fire scenarios that can occur on cruise ships are investigated in tests using full scale models. An example of this approach can be seen on one of its customer’s 200 metre long cruise ships. All public areas of the ship, which is subdivided into six vertical main fire sections, are protected with sprinklers – over 4,000 in total. Around 300 fire extinguishers, which are distributed over the entire ship, supplement the sprinkler protection in restaurants, stair wells, control stations, hallways, bars and cabins. The international regulation SOLAS 74 with its addendums, as well as the international code for fire safety systems (IMO FSS Code) apply in these public areas. This 1974 international treaty
describes standardised principles and corresponding regulations for the protection of human life at sea. It applies to ships which are authorised to fly the flag of a state which is party to the treaty.
The sprinkler systems of this cruise ship are fed from a 3,000 litre sprinkler tank, and a sprinkler pump with a capacity of 84cubic metres per hour. A jogging pump is also installed, which ensures that the system is supplied with water from a fresh water tank for over 20 minutes. After that, the water supply comes from the ship’s seawater tank. Various pressure and flow sensors in the sprinkler systems ensure that alarm signals are immediately reported to the central alarm panel on the bridge. Particularly sensitive areas, such as the bridge and the machine control room, where water damage resulting from mechanical damage to a sprinkler must be avoided, are protected by dry systems.
High-pressure extinguishing systems, such as the Minimax miniMarin spray system, offer an alternative to sprinklers. They are built like a conventional sprinkler systems but work with an operating pressure of approximately 28 bar and have special mini spray sprinklers. Due to reduced throughput, water is distributed as fine droplets. They combine the benefits of conventional sprinkler systems with those of fine-spray technology: the extinguishing nozzles are selectively activated only at those locations where a fire needs to be fought, but the water consumption is much lower than that of sprinkler systems, so considerably smaller pipes can be installed. In the event that the extinguishing system needs to be used, there is much less water damage due to the lower water admission. This is made possible by the special mini spray sprinklers which produce sprays so fine, that extinguishing effectiveness is increased considerably. These systems comply with the IMO Resolution A19/Res. 800 Revised Guideline for Approval of Sprinkler Systems, and with SOLAS Regulation II-2/12.
The fire dangers in on-board galleys and open kitchens are also considerable. Oil fires are the main concern here, because they can spread quickly. So in addition to the sprinkler systems, Minimax also installed seven carbon dioxide extinguishing systems in the fume hoods of the various galleys. The Minimax KS 2000 automatic extinguishing system is compliant with regulation MSC/Circ 99(73) and steps in before a fire can spread. Thanks to the Febramax extinguishing agent suitable for foodstuffs, galley operations can resume after a fire without a great delay.
Carbon dioxide also provides fire safety in the machine room. In case of fire, the extinguishing gas floods the entire area – after people have been warned to leave the room. Regulations require that a fire in the machine room be displayed clearly and that the proper measures are taken. For several customers, Minimax has equipped particularly high risk areas – such as combustion motors, boilers, separators and the burner fronts of garbage burning systems – with fully automatic object protection systems with fine-spray nozzles. Since 2002 all seagoing vessels (i.e. passenger ships of over 500 GRT and freight ships of over 2000 GRT) must be equipped with additional object protection in the machine room. The regulations SOLAS 74 II-2/7 and MSC/Cir. 913 specify a fixed water-based local fire extinguishing system.
Lessons learned
After the fire in the mooring deck of a cruise ship in Miami, the US Coast Guard required the special protection of these areas. While international regulations do not require fire extinguishing systems for mooring decks, this ship complies with these additional regulations. Two water spray systems protect the spot where the windlasses and the line cables are located, to ensure that the ship can also dock at US ports.
Accidents and catastrophes on ships lead to a strengthening of fire protection regulations. In the Star Princess fire in March, an area was affected for which there had long been no regulations – the balconies in front of the cabins. Balcony furniture and separating walls on this ship, as on many others, were made of plastic, while the balcony construction was made of aluminium because of its light weight. Even the fire doors could not prevent the fire from spreading to the interior of the cabins. Decks 8 through 12 went up in flames due to a fire that had started on one balcony. The Lloyd shipyard in Bremerhaven had to completely rebuild 73 cabins and six mini suites, including the bathrooms. 126 cabins were less damaged and were able to be restored. Even the corridors in front of the cabins were affected. The shipyard also had to restore a large portion of the equipment, including pipes and electrical systems.
Minimax researched this catastrophe and developed a solution that would have stopped the fire from spreading within a few minutes. Models of cabins at 1:1 scale were built, using the same materials and equipment that were on the Star Princess. The effectiveness of the balcony extinguishing system was demonstrated in a fire test, and an independent report from the Rostock Institute for Marine Safety confirmed the reliability of the system.
The balcony extinguishing system proved itself in two different test scenarios. In the first, it prevented a cabin fire spreading outwards – even with the external door open. In the second, the system’s two extinguishing nozzles quickly and reliably extinguished a large fire on the balcony. During the tests, which were also observed by representatives of leading dockyards and cruise liner companies, Minimax stuck closely to the requirements set by the standard for sprinkler tests, IMO Res A 800 (19), which forms the basis for the approval of sprinkler systems.
Up until now, fire protection regulations stopped at the ship wall. But international safety experts now agree that balconies on cruise liners are trailing behind regulations for all other areas of a ship. The reason is that large numbers of well appointed cabins with balconies are a relatively new feature in shipbuilding, so appropriate safety regulations have not yet caught up.
Following the accident, the MAIB (Marine Accident Investigation Branch), the British authority responsible for the investigation of accidents at sea, together with the IMO, called for the greatest possible urgency in strengthening the fire protection regulations. But it may take many months before relevant regulations for this sector have been approved. Nevertheless, with developments such as the balcony protection system, those who want to protect their ships against this risk need not wait. And because international standards were used in the tests, installation is a sure investment in the future, with Germanische Lloyd already having certified the system.
Olaf Roschninski is a marine engineer and Bernd Eilitz PR manager of German based extinguishing systems specialist, Minimax. www.minimax.de/en
