Safe operation of vessels operating in Polar Waters
Safe operation of vessels operating in Polar Waters
Goal
“The goal of the Polar Code is to provide for safe ship operation and the protection of the polar environment by addressing risks present in polar waters and not adequately mitigated by other instruments of the Organization.”
Learning Objectives
At the end of this course, you will be able to understand about
- Ability to contribute to safe operation of vessels in polar waters
- Understanding of ice characteristics and areas where different types of ice can be expected in the area of operation
- Understanding of vessel performance in ice and low air temperature
- Understanding of safe operations and ship manoeuvrability in ice
- Awareness to monitor and ensure compliance with legislative requirements
- Understanding to apply safe working practices, respond to emergencies
- Understanding and awareness of correct crew preparation, working conditions and safety
- Understanding the need to ensure compliance with pollution prevention requirements and prevent environmental hazards; and
- Understanding skills to perform manoeuvres in order to safely operate ships in ice conditions in polar waters.
The safety of ships operating in the harsh, remote and vulnerable polar areas and the protection of the pristine environments around the two poles have always been a matter of concern for IMO and many relevant requirements, provisions and recommendations have been developed over the years.
Trends and forecasts indicate that polar shipping will grow in volume and diversify in nature over the coming years and these challenges need to be met without compromising either safety of life at sea or the sustainability of the polar environments.
Ships operating in the Arctic and Antarctic environments are exposed to a number of unique risks. Poor weather conditions and the relative lack of good charts, communication systems and other navigational aids pose challenges for mariners. The remoteness of the areas makes rescue or clean up operations difficult and costly. Cold temperatures may reduce the effectiveness of numerous components of the ship, ranging from deck machinery and emergency equipment to sea suctions. When ice is present, it can impose additional loads on the hull, propulsion system and appendages.
The International code of safety for ships operating in polar waters (Polar Code) covers the full range of design, construction, equipment, operational, training, search and rescue and environmental protection matters relevant to ships operating in the inhospitable waters surrounding the two poles.
Fig 1: RMS Titanic
Fig 2: MS Explorer
What do these vessels have in common?
- Both hit ice
- Both sank
Both prompted important developments in maritime safety:
Titanic-SOLAS
Explorerr- Mandatory Polar Code
Evolution of the Polar Code
Fig 3: Evolution of the Polar Code 1978-2009
Fig 4: Evolution of the Polar Code 2012-2017
Fig 5: Polar code and Ship safety
Fig 6: Polar code and the environment
Fig 7: Application of the Polar code
New vs. Existing Ships
Ships with keel laying dates on or after 1 January 2017 are considered “New Ships” under the Polar Code.
Ships constructed before 1 January 2017 are considered “Existing ships”. Existing ships are exempted from several requirements that may otherwise be impractical to accommodate.
These include:
- Ice damage residual stability
- Escape routes arrangements for persons wearing ‘polar clothing’
- Navigation equipment redundancy (i.e., two independent echo-sounding devices)
- Enclosed bridge wings on ice class ships
- Oil tank separation distance from the side shell
The Polar Code Content
- Preamble
- Introduction (goal, definitions, sources of hazards)
Part I:
Included through a new chapter XIV in SOLAS
Part I-A: Safety Measures
Chapter1 General
Chapter2 –Polar Waters Operational Manual (PWOM)
Chapter3 –Ship Structure
Chapter4 – Subdivision and Stability
Chapter5 – Watertight and Weathertight Integrity
Chapter6 – Machinery Installations
Chapter7 – Fire Safety/Protection
Chapter8 – Life-saving Appliances and Arrangements
Chapter9 – Safety of Navigation
Chapter10 –Communication
Chapter11 – Voyage Planning
Chapter 12 – Manning and Training
Part I-B: Additional Guidance regarding the provisions of the Introduction and Part I-A
Part II:
Included in MARPOL Annexes I, II, IV and V
Part II-A: Pollution Prevention Measures
Chapter 1 – Prevention of Pollution by Oil (MARPOL Annex I)
Chapter 2 – Control of Pollution by Noxious Liquid Substances in Bulk (MARPOL Annex II)
Chapter 3 – Prevention of pollution by harmful substances carried by sea in packaged form
Chapter 4 – Prevention of Pollution by Sewage from Ships (MARPOL Annex IV)
Chapter 5 – Prevention of Pollution by Garbage from Ships (MARPOL Annex V)
Part II-B: Additional Guidance regarding the provisions of the Introduction and Part II-A
Operational Limitations
General
Polar Code introduces a concept of operational limitations, which are to be included on the Polar Ship Certificate (PSC).
It is recognized that within the polar regions there are significant variations in terms of hazards to shipping, primarily associated with variability of environmental conditions (such as low temperature, or the presence of sea ice) but also associated with remoteness and latitude.
Operational limitations are set for each polar code ship for:
- Ice Conditions
- Temperature
- Latitude
In addition the Polar Code requires a maximum “Expected Time to Rescue” (ETR) to be defined (and also included on the PSC).
Ice Conditions
Operational limitations for ice conditions are assigned based on the ship’s ability to function safely in ice. Polar Code requires that a methodology be utilized to determine a set of operational limitations for operating in ice.
Temperature
Operational limitations for temperature are assigned based on the ship’s ability (in terms of equipment, systems and materials) to function safely in low air temperatures. Polar Code makes a differentiation between ships that are intended to operate in low air temperatures and ships that are not.
Ships that are intended to operate in areas where the lowest Mean Daily Low Temperature (MDLT) is −10°C or warmer during the season of operation are not considered as operating in low air temperature. This is indicated in the Polar Ship Certificate. Mean Daily Low Temperature (MDLT) means the mean value of the daily low temperature for each day of the year over a minimum 10 year period. A data set acceptable to the Administration may be used if 10 years of data is not available.
Operation in low air temperature:
Low air temperature adversely affects human and equipment performance, survival time and material properties.
The Polar Code divides ships into two categories with respect to air temperature: those intended to operate in low air temperature, and those which are not.
A ship intended to operate in low air temperature means a ship intended to undertake voyages to or through areas where the lowest Mean Daily Low Temperature (MDLT) is colder than –10°C. For such a ship, a Polar Service Temperature (PST) shall be specified and shall be at least 10°C colder than the lowest MDLT for the intended area and season of operation in polar waters.
The Polar Code contains specific requirements for a ship intended to operate in low air temperature. These include general requirements that systems and equipment required by the Code must be fully functional at the PST. Survival systems and equipment also must be fully operational at the PST during the maximum expected time of rescue.
Fig 8: Temperature specifications
The lowest MDLT means the mean value of the daily low temperature for each day of the year over a period of at least ten years. To calculate it:
- Determine the daily low temperature for each day over a ten-year period in the intended area of operation in polar waters.
- Determine the average of the values over the ten-year period for each day.
- Plot the daily averages over the year.
- Take the lowest of the averages for the season of operation. This is the lowest MDLT.
If the lowest MDLT is colder than –10°C, then a Polar Service Temperature (PST) shall be specified. The PST must be set at least 10°C colder than the lowest MDLT for the intended area and season of operation in polar waters. For example, if the lowest MDLT is –15°C, then the PST equals –25°C.
Fig 9: Polar Service Temperature Definitions
MDHT – Mean Daily High Temperature
MDAT – Mean Daily Average Temperature
MDLT – Mean Daily Low Temperature
Latitude
Operational limitations for high latitudes are assigned based on the ability of the communication equipment on the ship to function effectively (transmit/receive) at high latitudes and the ship’s ability to navigate/determine course heading at high latitudes.
Part IA of the Polar Code requires equipment for effective ship-to-ship and ship-to-shore communication at all points along the intended operational route. Part IB of the Polar Code includes additional guidance on the operability of communication systems at high latitude:
“The theoretical limit of coverage for GEO (Geo Stationary) systems is 81.3° north or south, but instability and signal dropouts can occur at latitudes as low as 70° north or south under certain conditions. Many factors influence the quality of service offered by GEO systems, and they have different effects depending on the system design.“
For navigation, the Polar Code requires a global navigation satellite system (GNSS) for ships operating above 80° latitude (Part IA of the Polar Code). The Polar Code Record of Equipment provides for an entry to indicate if a GNSS is provided for if operations above 80° latitude are expected.
Both communication and navigation rely on the functionality of the onboard equipment and it is this functionality (or lack of) that will limit high-latitude operation. As part of the operational assessment, the specification of this equipment should be reviewed and evaluated against the design operating conditions.
Fig 10: Categories of ships operating in polar waters
Category A ship means a ship designed for operation in polar waters in at least medium first-year ice, which may include old ice inclusions. This corresponds to vessels built to the International Association of Class Societies (IACS) Polar Ice classes PC1 to PC5.
Category B ship means a ship not included in category A, designed for operation in polar waters in at least thin first-year ice, which may include old ice inclusions. This corresponds to vessels built to the IACS Polar Ice classes PC6 and PC7.
Category C ship means a ship designed to operate in open water or in ice conditions less severe than those included in categories A and B. This corresponds to vessels of any Baltic Ice class or with no ice strengthening at all.
Fig 11: Category A Ship
Fig 12: Category B Ship
Fig 13: Category C Ship
Polar Ice Classes
|
Polar Class |
General Description |
|
PC 1 |
Year-round operation in all Polar waters |
|
PC 2 |
Year-round operation in moderate multi-year ice conditions |
|
PC 3 |
Year-round operation in second-year ice which may include multi-year ice inclusions |
|
PC 4 |
Year-round operation in thick first-year ice which may include old ice inclusions |
|
PC 5 |
Year-round operation in medium first-year ice which may include old ice inclusions |
|
PC 6 |
Summer/autumn operation in medium first-year ice which may include old ice inclusions |
|
PC 7 |
Summer/autumn operation in thin first-year ice which may include old ice inclusions |
Chart 1: Polar classes
The Polar Class notation is used throughout IACS Unified Requirements for Polar Class ships to convey the differences between classes with respect to operational capability and strength.
IMO Polar Guidelines
- Only ships with Polar Class designation, based on IACS Unified Requirements for Polar Class Ships, should operate in polar waters
- Or comparable alternative standard of ice-strengthening
- Ice description follows WMO sea ice nomenclature
Fig 14: Maximum extent of Arctic waters application
(Above latitude north with exceptions on ice free areas)
The Arctic boundary does not follow the Arctic Circle (60°N Latitude). Instead it is modified to encompass the coast of Greenland, through to the Russian Arctic coast in the Barents Sea. This means that the Polar Code does not affect Iceland, Norway and the Kola Peninsula in North West Russia as for the majority of the year they are ice free. In the Bering Sea the limiting latitude is 60 degrees North.
Fig 15: Maximum extent of Antarctic area application
(Above latitude south Special for the IMO Polar Code: geographical application)
In the Antarctic the boundary is simple – it is the 60°S Latitude.
Fig 16: Boundaries of Antarctic area and Arctic waters
- Antarctic area means the sea area south of latitude 60° S.
- Arctic waters means those waters which are located north of a line from the latitude 58°00΄.0 N and longitude 042°00΄.0 W to latitude 64°37΄.0 N, longitude 035°27΄.0 W and thence by a rhumb line to latitude 67°03΄.9 N, longitude 026°33΄.4 W and thence by a thumb line to the latitude 70°49΄.56 N and longitude 008°59΄.61 W (Sørkapp, Jan Mayen) and by the southern shore of Jan Mayen to 73°31'.6 N and 019°01'.0 E by the Island of Bjørnøya, and thence by a great circle line to the latitude 68°38΄.29 N and longitude 043°23΄.08 E (Cap Kanin Nos) and hence by the northern shore of the Asian Continent eastward to the Bering Strait and thence from the Bering Strait westward to latitude 60º N as far as Il'pyrskiy and following the 60th North parallel eastward as far as and including Etolin Strait and thence by the northern shore of the North American continent as far south as latitude 60° N and thence eastward along parallel of latitude 60° N, to longitude 056°37΄.1 W and thence to the latitude 58°00΄.0 N, longitude 042°00΄.0 W.
- Polar waters means Arctic waters and/or the Antarctic area.
