NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: DR thread from Nov-Dec '04
From: Doug Royer
Date: 2005 Jan 18, 10:36 -0800
From: Doug Royer
Date: 2005 Jan 18, 10:36 -0800
After reading my origonal post on this subject I noticed I wrote the set discription incorrectly.I appologise for any confusion I caused and will clear it up now. If the wind is out of the north at 360 * T the set will be in the direction of 180 * T.If the wind is on the starboard beam the resulting current will push the vessel toward the south.That issue now being corrected the set of the wind driven current will be in the direction of 220 * T,not 320 * T. Again, 360 *T - 180 * T = 180 * T. 180* T + 40 *(to the right of the wind direction)= 220 * T. Don't let my mistake deminish the importance of this effect. Doug > When engaged in commerce shipping time is money and > money is time. I also imagine it takes more than pocket change in fuel for those few extra miles as well. Must make a cigarette boat look like a hybrid economy car ;-) Do you have a ball-park figure for gallons per mile for an average loaded freighter? The larger,older freighters use bunker oil for propusion.Some of the newer vessels use gas turbine technology but the majority use diesel.The nomenclature for fuel cunsumption in these vessels is in barrels/hour for a given rpm of the shaft.I believe there are 42 gallons/barrel.A vessel of this size can easily consume 100s of barrels/day depending on speed,draft and sea conditions.I'll get an example of this tonight and post it tomorrow. > "The Merchant Marine Officer's Handbook" 4th or 5th edition devotes space to > it in the chapters dealing with shiphandling and pilotting. I haven't seen a > 6th edition yet. > > Other than that one book perhaps in other marine teaching institution's > sylabus as that is where I was 1st exposed to it. I first noticed it in the Annapolis Book of Seamanship, and then aware of it, noticed it in a a couple of other texts. Memory fails, but I would guess Dutton's, Chapman, and Bowditch would be rounded up as the usual suspects for a line up. I'll look at my older editions of Dutton's and Bowditch tonight and see if I can find referance to this in them.I don't remember it being in Dutton's but it's been awhile since I dusted my copy off. What is the "Annapolis Book of Seamanship" ? Is it a book used to teach midshipmen or cadets at the Naval Academy? Bill