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#Industry News

Polar liferaft

SurvitecZodiac has spent over 2 years developing a heating system for its whole range of commercial liferafts- thus making all the rafts in its range meet the new IMO Polar Code requirements when the new ‘Arctic’ option is chosen. We travelled to SurvitecZodiac’s high tech factory in Chevanceau, France to find out how the company achieved it.

The new IMO Polar Code has stipulated that liferafts must be operable in temperatures down to 10deg C below the ambient temperature. As this isn’t hugely specific, manufacturers, through a trade body, have reached a consensus that this constitutes a deployable temperature of -50deg C.

The problems in achieving this are manifold. For a start, getting hold of a facility in which the system can be developed is a hurdle. While there are plenty of commercial freezers that can do minus 30 or minus 40, minus 50 is a bigger ask. SurvitecZodiac’s standard rafts operate in a wide temperature range from -30deg C to +65deg C, but the development of this system required use of an off-site testing facility courtesy of Zodiac’s Aer Azure aerospace sister company.

What all manufacturers are working on to achieve the standard is systems to heat the packed raft in its container. This removes all the fears of seals becoming non-operational, cold cracking of the liferaft fabric on inflation and underperformance of the gas inflation system. It is also necessary to heat the hydrostatic release unit, which sits outside the raft so this has to be done separately. The release system manufacturer (Hammar) provides the heating system for this- but it is integrated into the raft’s heater control system. SurvitecZodiac has achieved the warming of the packed raft by using a conductive material blanket, wrapped around the packed raft, that is connected via a control box to the vessel’s emergency power supply. Although the company was unable to comment in detail on how competitors were meeting the standard, it’s thought that various methods could be employed from heating elements encased in silicone to pumping hot water in tubes around the raft.

The beauty of SurvitecZodiac’s approach is that the blanket, contains no metal to corrode or break contact, spreads its heat completely evenly with no hotspots and shuts off automatically when it reaches 30deg C. The fabric was developed for cold weather clothing, so is safe, proven and flexible. Because it is a lightweight fabric, its inclusion does not affect the float free characteristics of any of the rafts in the range.

Maritime Journal was also shown a control box for two rafts. The box is designed to be within the vessel accommodation and uses a system of switches, sensors, lights and relays to switch the system on automatically below +3deg C and indicate that it is working correctly.

At time of writing only one other choice of supplier is available, and demand is such that SurvitecZodiac has already sold two ship sets of its Arctic Liferafts to a yard in China.

Details

  • Chevanceaux, France
  • SurvitecZodiac

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