Nudge Wrote:
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> Many years ago, most all rail was in 39 foot
> sections. That what fit on 40 foot flat or gons.
> The weight was figured to how much a yard weighed.
> If one yard weighed 110 pounds, it was 110 pound
> rail.
>
> The one problem with 39 foot sections was the side
> to side roll at 15 mph. You either had to go 10
> mph or 20 plus through sidings, yard tracks, etc.
>
>
> SP had their rail plant over in Tracy where they
> would cut off rail ends and weld used rail in 1/4
> mile sections. The rail was relaid with the old
> inside, on the outside giving it a new life as
> ribbon rail. The Tracy plant knew where the rail
> came from down to the mile post. They figured
> wear, etc and knew where it should be placed back
> out in the field. With new, heavier rail they
> still welded each stick together and it was sent
> out to where they were up grading curves and main
> lines.
>
> Im sure there is someone else on here that can
> give more of an insight.
>
>
> Nudge

I think harmonic rocking speed is between 13 and 22mph and therefore railroads had a rule that crews that could not maintain 23mph had to reduce to under 13mph. Railroads would specify by subdivision where this rule applied since obviously it wouldn't be a problem on (well maintained) welded rail. If not tamped during installation ribbon rail could cause the same rocking as the previous jointed rail.