Re: No consideration of the piers, abutments and foundations! Re: Lobato Trestle Report

Dave Boyer Wrote:
-------------------------------------------------------
>> The "superstructure" are the spans between piers.
>> HDR did a structural analysis of these spans and,
>> even though HDR ignored the dynamic loading from
>> the locomotive drivers and cars, the spans still
>> failed the analysis.
>
> A scary conclusion. The fire may have saved the RR
> from a trestle collapse with engine and
> passengers. They may have dodged the proverbial
> bullet.

Dave, "failed the analysis" does not mean that a collapse was imminent. While iron railroad bridges are outside my areas of expertise, the report seems to be saying that the loadings applied by C&TS trains were causing the bridge to wear out prematurely. This strikes me as somewhat ironic because they are talking about a 100+ year bridge!

However, I'm a little disappointed to read this:

Quote
Second paragraph of "Rating Results", on page 7 of the report
Per information provided by the Cumbres and Toltec Scenic Railroad two (2) trains per day, one in each direction, pass across the bridge at a maximum speed of 8 MPH. The train consists of a K36 or K37 coal fired steam engine locomotive, tender and eight (8) viewing cars with a maximum capacity of 44 passengers per car.

Based upon this, HDR did not consider light helper moves, Cinder the Bear specials, photo freights (e.g. Chama Steam), nor work extras.

--
Chris Webster