In recent years, (sub-)arctic activities have increased substantially in oil and gas, marine transport, fishing, science and research, and tourism industries. Due to their geographic location, these activities hold a high risk while they cope with extreme conditions, such as sub-zero temperatures, limited amounts of daylight, and their remote operating environment. As a consequence, the demand for winterized vessels with a minimum of ice reinforcement is increasing.
Standards for Working in Extreme Weather Conditions
International standards provide guidance to manufacturers and operators of this type of equipment. DNVGL-OS-A201 is one of the world’s most comprehensive and followed set of principles for winterization and provides design principles for mobile units and offshore installations intended for cold-climate conditions.
Classes Winterization Requirement
Winterization requirements can be broken into two classes:
- Anti-icing is the prevention of ice formation. Anti-icing requirements are generally related to personnel safety working in extreme weather conditions. They include emergency passageways, helidecks, and emergency doorways. These areas must be kept free of ice for a possible evacuation during the worst expected conditions.
- De-icing is the removal of ice from an area. De-icing requirements aim to prevent excessive ice loading on frequently used access ways, such as the lower deck, stairs, handrails or walkways.
People working in extreme weather conditions make sure that their personnel and equipment is protected at all times and year-round.
Choosing Appropriate Anti-Icing and De-Icing Techniques
Since anti-icing and de-icing measures can vary widely depending on environmental conditions, it is important to determine the specific temperature conditions for winterization.
A variety of methods exist, both active and passive, such as steam, hot water, chemical freezing point depressants, ice-phobic coatings, infrared radiation, and electric heat tracing. Mechanical approaches using shovels or hammers may work on smaller areas but are not practical for larger sections of a vessel. Not only that but manual methods put personnel in harm’s way by exposing them to harsh weather conditions.
Electric heat tracing has been used for both anti-icing and de-icing for many years. It has proven to be effective and reliable for a wide range of applications including walkways, handrails, stairs, helidecks, and many more.