Re: Rails to Trails bridge progress

Bill Tindall, E.Tn.
some times a picture is NOT worth a thousand words if the picture does not clearly show the details. I have worked on this bridge enough that I know every piece of lumber, screw and bolt in it. No mistakes so far except for the I-beam flanges.

Unknown to us, but what should not have been unknown to our consulting RR engineer, the top flange of the I-beam is composed of 3 plates at the beginning, then stepping down to 2 and finally one in the middle of each span. The result is a variation in height from zero in the middle to 1.5" higher at each end of each Ibeam span. When the bridge was originally decked with ties they were notched at different depth to result in a level top of the ties.

We began laying un-notched ties and then encountered this step in height. I was in France at the time. Had I been on scene I would have shimmed the I-beam to bring the top of all the ties into the same height. The ties were laid down without shimming and the result is a wave along the length of the bridge deck. We are going to attach the rail so that it is straight across the top and accept the undulating deck.

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