I have a set of Railroad curves (well that's what we called them, but they are not spirals) that I bought from Advance Survey Equipment in Nashville back in 1982 or so. They were $250 then.
I don't have a use for them any longer and wonder if anyone wants to but them for $100 + shipping?
If you're interested email me and I'll send pictures. There is a total of 55 curves from 0å¡-15' to 20å¡-0' with only the 12å¡30' one missing.
Just a point, is it Railroad curves that are identified by arc angle and Highway curves by Radius?
Thanks,
Dtp
foggyidea, post: 357504, member: 155 wrote:
is it Railroad curves that are identified by arc angle and Highway curves by Radius?Dtp
I think so, but not real sure. I still have mine, I thought they were double marked. Need.More.Coffee
Those were indeed the best way to draw an arc by pen or pencil in creating a drawing before cad.
I had to settle for an adjustable arc in 1988.
I believe RR curves are defined mostly by degree using the chord definition. Highway curves are usually defined either by degree (arc definition) or radius. I have seen some very old highway R/W plans using a chord definition for degree of curve, for what it's worth...
The only superior evidence is that which you haven't yet found.