Posted by: wlsc1979 | 2010-09-18

New Bridge Height Information

I’ve added some new info on bridge height info which is stored in the link under the main picture on site labelled “Lake-Info.”

I’ve duplicated the info below:

Lake Level on Internet and Mast Height:

It is important to consider the bridge height for some boats depending on the time of year.  Be sure to include any antenna or windex in your estimations of bridge clearance.  If not, you will not be the first to shear things off the top of your mast! 

The data below is for information and guidance only.  Before attempting to pass under the bridge, the skipper should assure himself that sufficient clearance exists to allow safe passage.

I’ve included two sources of information.  The first was that made by Bill Murdoch.  I’ve included a note below from Bill about his experimental method:

“I finally got around to measuring the clearance under the Butler Bridge this week.  Monday was a nice day, and I had finished messing around on the boat.  I borrowed a marker from the little store beyond Shirley’s to number the bridge panels on the railing so I could keep up with them.  With a steel tape and a plywood board on a long eye bolt, I measured the height of the bridge above the water in four places.  They were hauling dirt from the Butler side of the bridge to our side, and I can tell you for a fact that the bridge goes down one or two inches when the trucks go by.”

see his results:  http://littledomain.com/files/butler_bridge_elevations.pdf

There other experiment was peformed with a sextant by John Middaugh.  See his note below:

“Bill that is very good work.  And should be very accurate.  When I measured it several years ago with my sextant, the area half way between A & B, I got 8 to 10 ft and felt 8 ft was close.  If I did the math correctly half way would be about 2009.31 elevation.  Which would be about (My chart I believe shows 2002.00 ft at the mid point) or 7.31 ft higher than the middle of the bridge.  So I feel pretty good about my measurement with the sextant.  The point half way between A & B probably would be the location a sail boat could pass under the bridge in comfort with respect to the shore.  I believe when I passed under it this Summer I tried to stay South of point B.  And even at this point my mast brushed close to the trees.”

“I guess I should have subtracted the actual  mid point of the Bridge 2003.35 ft from the mid point between A & B which would be (2009.31 ft) or 5.96 ft.  Thus 5.96 ft or about 6 ft higher than the middle of the Bridge.

“Again this is excellent work and should be very accurate the way you measured the elevations.  This will be of great benefit to Wayne, Minta, Robert, and all the other sail boats with the higher mast.  It will give every one a little more confidence about going under the Bridge.”

Lake Level from Internet:

http://lakeinfo.tva.gov/htbin/lakeinfo?site=WTH&DataType=All&submit=View+info

Lake Level by Phone:

800-238-2264, 1 for lake levels and then 02 for Watauga Lake.


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