[Oregon Short Line Railroad] O.S.L.R.R. Spiral Curves Searles Method Booklet

Item Details

[Oregon Short Line Railroad] O.S.L.R.R. Spiral Curves Searles Method Booklet, Office of the Chief Engineer--O.S.L.R.R., Salt Lake City, Utah, 1899. 6 3/4 x 4 inches, 12pp.

Staple-bound booklet in blueprint paper. Very light wear. Fine condition.

Engineering booklet for determining spiral curves for railroads using the Searles Method.  Filled with charts and diagrams used for determining spiral tangents from 10 ft. chords to 50 ft. chords. 

The Searles method was developed by William Henry Searles as a surveying technique for designing and laying out spiral curves that connect a straight tangent to a circular curve. Not sure what this all means--I did poorly in Geometry.

A nice, uncommon ephemeral item from the Oregon Short Line Railroad which connected Wyoming and Oregon and was a subsidiary of the Union Pacific Railroad.