[Ted Davisson]

Greetings From New Orleans ,

Bob , thanks for your thoughts and input on this topic but there is another issue that comes into play here as well .

Its my understanding there is anoyther factor that is refered to as a vessel's Fresh Water Allowance and is the varible that comes into play when any vessel makes a transit to or from fresh water and salt water .

Today , for example I am on a ship that has a Fresh Water Allowance of 213 mm and when calculated to feet and inches , it comes to just over eight inches lower in the water when the same vessel is in a fresh water environment .

When the Str.'s Delta Queen and Delta king were working in the San Francisco to Sacromento trade no telling where the salt water finished and where the fresh water began . Another issue that effected the location of the fresh and salt water was the amount of fresh water that was coming out of the heaqdwaters of the Sacromento River . When the Mississippi River is at a dead low condition for any length of time , I know that New Orleans and all the lower towns and communities that line the river experience what is referred to as salt water intrusion . This salt water intrusion that literally comes up the river contaminates the water supplies of these same towns and communities to such an extent that many times fresh water has to be literally trucked down to these sames towns and communities .

My point is to all this is that even if the paddlewheels on these two steamboats only sinks an additional six to eight inches , these same paddlewheels would in all likelyhood loose a certain degree of efficiency , speed and ultimately control .

It has also been brought to my attention that the Plimsol Lines that are present on the mid ship section of a ship or sea going barge are there to mark the seasonal load lines that a vessel may be loaded down to .

Smooth Sailing !
Ted Davisson
WA-4141

Originally Posted by Bob Reynolds

Ted, when loading barges in salt water, we were always told to load 6 inches light if we were going to deliver in fresh water. I have noticed about the same thing in more recent years, that if we load in fresh water (St. Louis) for delivery to a Gulf coast port (say, Panama City, FL), that the 6 inch rule is pretty good. I know it is not perfect, especially when you get to deeper drafts and larger volumes, hence the Plimsoll marks you see and use on ships.

So, in answer to your question about the DQ drawing considerably more water on the Mississippi than she did in SF Bay, I don't thiNEnk it would really be any significant difference. I think also that the water in Sacramento is pure fresh water, though I don't know this for sure.