What are some good recommendations when sailing in cold weather conditions?
Are you asking about sailing boats or are you wondering about cargo an passenger ships?
Your question is quite general; therefore, I will narrow it down from an OIL Tanker point of view.
Before navigation in expected freezing conditions or near ice,
- Both Bridge and Engine must be aware prior to sailing in cold areas.
- An additional lookout is to be posted.
- Weather and tight doors are secured.
- Both radars are in operation at appropriate ranges.
- Ice advisory service Broadcasts monitored and plotted.
- Transmitting weather reports to the appropriate authorities in accordance with SOLAS 1974 Chapter V, Regulation 2(a).
- Speed and course adjusted as necessary for safe navigation.
- Navigation should be performed in accordance with Bridge Procedures Guide.
- All ballast tanks have to be slacked off about 10-15% of their capacity. Use seawater for
ballast. If the vessel has been ballasted at terminals/areas with fresh water, then ballast
should be exchanged with seawater as per Water Ballast Management Plan.
- Ensure that all freshwater tanks in contact with the side shell or main deck are slack at about 15-20% of their capacity.
- All fire and foam lines on the deck to be drained and blown with air and all fire hydrant to be opened. Draining to include valves.
- Steam supply and return lines on deck to be drained and all steam drains to be opened.
If steam needs to be supplied on deck, then extra precaution and very slow warming to be observed. All cargo lines on deck including cow lines and MARPOL line to be drained prior to entering in cold weather.
- Steam to be supplied to the deck seal unit. Fresh water supply line to vacuum tank in pump room to be covered in order to be protected against freezing. Same to be applied to the vacuum tank in the pump room, particularly during the discharging operation.
- P/V breaker to be filled with proper antifreeze liquid. Drain lines of the vapor recovery system to be drained.
- Maintain P/V valves free of ice.
- Air on deck to be closed and the line to be drained.
- All motors of hydraulic power packs for deck winches and windlasses to be run at least 12 hrs prior to use. Motors to run for one hour at four hours intervals.
- Motor for the steering gear to be run continuously. Motors of cranes to run for one hour at four hours intervals.
- Prior to arrival at the berth and during the ship’s stay alongside the berth all mooring stations and their accesses to be free of ice for immediate use.
- Fresh water cooling of Emergency Generator to be filled with proper antifreeze liquid. Emergency Generator to be operated from time to time as found necessary.
- Life boat’s engines to be dry of their cooling water. (Water in a container to be stood by in case the lifeboat has to be used).
- Lifeboat freshwater containers to be slacked about 15% of their capacity.
- Bridge window fresh water washing line to be drained.
- All steam lines of sea chests of the Engine Room and Pump Room to be ready for use at any time if the necessity arises.
- Engine Room vent/exhaust fans to be used in such a way as to maintain Engine Room temperature at acceptable levels.
- Sea water to be re-circulated in order to keep the cooling water temperature within normal operating limits.
- If there is a need to use electrically operated heaters in any part of the ship then a suitable patrol procedure should be established to avoid possible fire risks.
- The aspects of icy and slippery working areas on mooring stations have to be seriously considered. De-icing by use of salt and steam smothering is to be done in order to improve the Safety of the working environment.
- Avoid the immersion of the ropes/wires into the water.
- As the Acetylene / Oxygen Rooms are located in an open area, please pay extra attention if Foam extinguishers ( with a Temp range +5 to +60) are used for firefighting to be replaced with Dry Powder extinguishers (with a Temp range -30 to +60) which is capable to operate in low Temperatures.
- Dump pipes in the way of slop tanks to be filled with anti-freezing liquid.
The above operating measures can be supplemented by additional measures based on the particular characteristics of each ship.
In addition, you should take care of the lifeboat air cylinders pressure, because it will drop gradually. Pressure won’t go down fast but it will slowly be reduced. Therefore the Chief Officer or the appointed Safety Officer on board must keep in mind to fill up the cylinders prior to arrival at port. (Avoid a 3rd party observation) For example, if we fill up an air cylinder at 30 degrees Celcius with 200 psi of air, then the same cylinder at 0 degrees Celcius will have a pressure of 180.20 psi.
PV = nRT ,
where P , V and T is the pressure, volume and temperature of gas respectively; n is the amount of gas, and R is the ideal gas constant.
Hope it helps
@Nick thank you for the very detailed response. Indeed very helpful.
Have a nice day!