Made a little video of the first run over the new bridge and tunnel. Inner loop will probably get done in the spring, after a new waterfall pond is made on top of the tunnel. Song is by Lonesome Spurs.

Jerry, That is one big honkin bridge.  Very impressive.  It looks like it will handle another track too. Scuse me, but I don't know that engine.  What exactly is it.

Paul

Jerry,

why are you waiting until spring to finish the projects?  retired so you have nothing to do all day long and you don't waste time shaving in the morning????

Mr. Barnes,

 

Please don't spoil the effect of a very nice, very impressive bridge by adding a pier at or near the center of the span as additional support. All spans experience some sag. Mark's Mechanical Engineers' Handbook has calculations for the sag induced by mass of any beam. Without specifically referring to the formulae that are included, it is my suspicion that the center sag that you have noted is a natural effect and will not result in the eventual failure of the span.

 

The only concern that I have is the bridge constructed of material with sufficient mass and structural strength to support the maximum intended load for the span. Place a mass at the center of the span equivalent to the maximum load the span would experience and determine the deflection caused by this load. If it is no greater than the natural sag of the beam supported at two ends then you have no concern. You would not require a center support pier to avoid collapse under maximum beam load.

 

Your effort is most impressive in its location and deserves to be maintained for its sheer impact on viewing.

 

Respectfully,

 

NYC Buff

Jerry,

forgot about the winter storm going through your part of the country.  We had 65 degrees yesterday, only getting up to 55 today.  However, I know Michigan's mother nature is going to make us pay for this unseasonable warm weather.  So, I steam when I get the chance.  Keep warm and do those "winter projects".

Bill