Weather Routeing Flashcards
What are the considerations the Master must consider if his passage would benefit from Weather Routeing?
- Distances over 1500nm
- Experience of TRS or Tropical Storms
- Navigation Experience & Competence of Crew
- UKC Requirements
- Loadline Zones
- Engine Power & Consumption
- Stores & Port of Refuge (SRTP - Safe Return to Port)
- Ice Limits
- Cargo OR Passenger Requirements
- Location of Passage
What are the types of weather routeing available?
- Synoptic
- Climatological
- Shore Based
Describe THREE types of weather routeing currently available to vessels?
Onboard; by ship’s staff, using information from climatological data and broadcast forecasts. The first approximation of the route is the shortest distance with adequate margins of safety. Climatological and forecast information is used to decide whether a deviation from this is justified in order to achieve the optimum route.
On board; using computer programs with data supplied from ashore. The program holds information about the ship’s performance in a variety of weather conditions. The program holds climatological information. Forecast information is received from ashore. The program calculates an optimum route for the vessel.
Shore based; Routeing Officers. An organisation ashore has details of the ship’s performance, climatological data and forecast information. A Routeing Officer, using a computer program, calculates an optimum route for the vessel and advises the Master accordingly. Weather forecasts and further routeing advice are provided throughout the voyage.
Outline the benefits of carrying out shipboard routeing?
Local meteorological conditions and changes can be observed directly
• Appropriate action can then be taken in response to changes as soon as they occur
• The performance characteristics of the vessel in different circumstances are known by the Master in detail
• The performance of the vessel in response to the prevailing conditions can be directly assessed and appropriate adjustments made
• The original plan can be modified quickly in response to changing conditions to maximise the efficiency of the voyage
• Information obtained through the internet or otherwise can be used to improve forecasting
• Low cost
What are the advantages of Shore Based routeing?
The shore based company will do the work for the Master and bridge team, receiving and interpreting the data specific for:
- Vessel characteristics
- Route of Passage
- Charter / Company Requirements
Positives:
- Professional application of raw data
- Forecast ahead
- Voyage optimisation
- Can predict future trends
What are the factors to consider from the charter / company when using Weather Routeing?
- Least Time (+ve = tankers due to less vulnerability of cargo and hull damage - -ve = other vessels)
- Least Damage (+ve = for sensitive cargoes - -ve = longer passages & not as fuel efficient)
- Least Time & Damage
- Constant Speed (+ve = charterer gets cargo at their requested time - -ve = adverse conditions, reduce speed, delayed, fined if late)
- Fuel Saving (+ve = lead to less time as well - -ve = adverse conditions encountered means fuel usage increases)
State 14 types of information found on a Routeing Chart?
Routeing Charts:
o Show climatological data for each ocean and month of the year.
o Wind roses; direction and proportions of
o Beaufort Force.
o Predominant ocean currents; direction, rate and constancy.
o Shipping routes and distances.
o Sea ice and iceberg limits.
o Loadline Zone limits.
Inset chartlets of:
o Air pressure and temperature
o Dewpoint and sea temperature
o Percentage fog and low visibility
o Tropical storm tracks and percentage wind greater than force 7
What information would you typically find on a routeing chart wind rose?
- Wind force & direction (measured in Beaufort scale - in order: force 1-3, 4, 5-6, 7, 8-12)
- Number of Observations
- % of variable winds
- % of calms
