90. What is "ship route forecasting"? 



The shortest route between two points on the globe is a great-circle 

 track; however, because of sea conditions. It Is not always the fastest or 

 safest. In one year (1954), more than 6 percent of the world's shipping 

 experienced weather damage. Another 3 percent was Involved In col- 

 lisions, some of which were caused at least partly by weather condi- 

 tions. 



In the early 1950's> the U.S. Navy established a ship routing service 

 which Is a modern version of the service provided by Lt. Matthew Maury 

 before the Civil War, when he gathered the logs of ships and produced 

 charts of ocean currents and winds. Maury's work resulted In saving days 

 or weeks in the journeys of sailing vessels; now time savings are meas- 

 ured in hours. By 1958, It was found that the travel time of Military 

 Sea Transport Service ships from New York to Bremerhaven had been 

 reduced from 1 days to 9. 



The principles of ship routing are simple. Marine meteorologists pre- 

 dict wind speeds and direction for the area of Interest. A chart is pre- 

 pared to show lines of equal wind velocity and these are translated Into 

 charts of expected wave heights. By use of these charts maximum attain- 

 able speed can be computed for any type of ship. A ship using this 

 service maintains communication with the individual supplying the 

 routing service and receives a dally course to be steered. 



Although ship route forecasting was developed by the military, pri- 

 vate forecasters furnish the same service to commercial ships. 



James, Richard W. 



Application of Wave Forecasts to l\/larine Navigation, Special Publi- 

 cation No. 1, U. S. Naval Oceanographic Office, July 1957. 



Marcus, Sidney 0., Jr. 



"The United States Navy Hydrographic Office Ship Routing Pro- 

 gram," Transactions of the New Yorl< Academy of Sciences, Vol. 

 21, No. 4, February 1959. 



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