--- On Thu, 30/7/09, Aun Johnsen (via Webmail) <[email protected]> wrote:
> > You also mentioned sailboats under bridges, are you
> planning to update
> the
> > clearance 24 hours a day, 7 days a week as the tide
> goes in and out?
> You are clearly not familiar with the term "free sailing
> height" which
> refers to the height from mean sealevel (used in marine
> charts), up to a
> portion of the bridge span which os over the safe channel.
> This value is
> stated in all marine charts as a reference to any ships
> captain for him to
> verify that his vessel can pass safely under the bridge
> with his current
> air draft. There is no need to correct this more often than
> the bridge is
> reconstructed as you will correct this value towards tidal
> information
> available for the closest port.
No, my point is, clearance is pointless, the clearance would be altered by the
tide where as "maxheight" would remain the same regardless of the tide etc.
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