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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Barrels was DR thread from Nov-Dec '04
From: Doug Royer
Date: 2005 Jan 19, 10:00 -0800
From: Doug Royer
Date: 2005 Jan 19, 10:00 -0800
And more fun than a barrel full of monkeys equals? ;-) Bill I got a chuckle out of the above. I checked my copy of Dutton's 12th edition last night and in sec. 806 was a 2 paragraph discription of this phenominon. My copy of Bowditch 1984 edition,chapter XXXII has a better explaination.This is known as the Ekman Spiral or Ekman Current as George pointed out. So,the phenomina is well documented in other pubs. As for Bill's question about turns and fuel consumption the easiest way for me to show how much fuel these larger,laden vessels consume would be to take a question out of the C.G. exam for 3rd mate,unlimited as an example. Q: The speed necessary for reaching a point at the designated time is 18.0 kt.The pitch of the prop is 23.9 ft.How many rpm will the shaft have to turn with a - 2 % slip to reach the point in the given time? My calculated rpm = 77 rpm If the fuel consumption at the above shaft rpm is 215 barrels/day what will be the fuel consumption if the vessel's speed is reduced to 14.0 kt.? My calculated consumption = 102.3 BBLS/day The correct answer = 101 BBLS/day Close enough to pick the correct answer out of the supplied answers but my calculated rpm is apperantly high as shown by the 102.3 barrels instead of 101 barrels.So,in real life, you can see that a fair amount of money would be lost if calculated incorrectly.