Polar liferaft rules - mean or misunderstood?
The Polar Code brought rigor to rules covering ships operating in extreme temperatures, but misunderstandings remain over what qualifies a liferaft as suitable for the poles.
Rising global temperatures underlie rapid growth in commercial opportunities for ice-capped expedition cruising and Northern Sea Route cargo moves but safety is the dominant issue for ships operating in the realities of severe weather, low temperatures, and ice. Nature at the poles is spectacular, exciting, and unspoiled, but it is also cold, dark, wild, and a long way from the nearest rescue center.
The response merited several degrees of extra rigor from IMO regulators in developing the Polar Code. The Code, finalized in 2017, provides risk-based rules for everything from ship structures to training, voyage planning, navigation, and equipment performance in polar waters. All cargo ships larger than 500 tonnes and all passenger vessels carrying more than 12 passengers operating within the IMO-defined boundaries of the Arctic and Antarctica must comply.
Mean all day
Despite the level of detail, misunderstandings persist over what qualifies a liferaft to claim ‘polar’ status. Standard SOLAS liferafts are tested and certified to meet cool inflation temperature requirements of -30°C, but this does not mean that a ship operating at -30°C mean day temperature in polar waters and using standard SOLAS liferafts is compliant under the Polar Code, he says. The source of the misunderstanding is that vessel owners sometimes believe the ‘cold inflation’ test temperature is linked to the allowed storage and carriage temperature requirements within the Polar Code.
Our special Polar container is equipped with internal heating mats that serve the dual purpose of keeping the liferaft as well as the container ice-free, ensuring that the system is always ready for deployment.
If an inflatable liferaft is tested for 24 hours stowed at a temperature of -30°C, this does NOT mean that it is acceptable for a Polar Code ship following the PST -30°C standard.
Standard assumptions
Instead, the Polar Code allows the ship operator to make the general assumption that standard LSA and PPE equipment will be acceptable during voyages when the Mean Daily Low Temperature (MDLT) does not fall below -10°C at the season of operation. This is the threshold value agreed by IMO after considerable deliberations for the Polar Code and defines a ‘ship intended to operate in low air temperature.
The PST, in contrast, is always set 10°C lower than the MDLT, which means that a ship operating in an MDLT of -30°C must ensure that all systems should be constantly stowed and operational at -40°C (i.e. PST -40). Survival systems and equipment must be fully operational at the PST.
As the first supplier to offer polar liferafts packed in special containers with built-in heating for full operability down to -52° C, VIKING has also established a leading position in this part of the market by by being able to supply polar grade safety products for the full scope of LSA.
IMO novelty to polar normalcy
VIKING polar liferafts comply with Russian winterization regulations and DNV rules for winterization and are certified by DNV, TC Canada, RMRS and USCG.
Having now supplied around 800 Polar Code-compliant liferaft already, with recipients including some of the expedition ships, gas carriers and tankers responsible for transforming polar routes from novelty to normalcy, VIKING is keen to help others follow in the wake of the industry frontrunners.
With polar conditions expected to play an increasing role in world shipping, one key will be life-saving equipment that offers day-to day useability, no matter what the challenges. In recent months, VIKING Polar liferafts have been verified as fully functional at temperatures as low as -52oC and tested down to -62oC, he explains.
“Our liferaft are equipped with thermal sensors and feature internal heating mats that serve the dual purpose of keeping the raft and the container ice-free so that the system is always ready for deployment.
“When the temperature drops below 5°C, a thermal control box activates the heating mats. For extra safety, the control box can be connected to the ship’s alarm system. When the temperature outside the liferaft rises above approx. 5°C, the control box automatically deactivates the heating to save power.”
Should a system failure occur for any reason, the heated hydrostatic release unit (HRU) and the heated liferaft are monitored by a failure alarm signal that notifies the ship's bridge.
Resulting recommendations
VIKING Polar liferafts are also fitted with all the equipment required under SOLAS and 30% more rations, the latter based on the assumption of lasting three days. Additional water, food and equipment to support survival for the five days required in the Polar Code must be carried in the Personal Survival Kits (PSK) and the Group Survival Kit (GSK).
The liferaft container has a built-in thermo sensor to supply the vessel with an alarm signal if the temperature inside goes below -20°C. “Of course, that means that any water inside the liferaft would actually be frozen, and for this reason, the occupants also need the content of the PSK and the GSK to melt the ice.
The Polar Code considers hazards that may lead to elevated levels of risk, where LSA designed for Polar conditions take these hazards into account.