What is this prototype diagram called and what do the numbers represent?

[DSchmitt]

The 66-foot Gunter’s chain is as you described, particularly regarding cadastral surveying. Original railroad alignments (from the 1830’s or 1840’s, or whenever) might have been laid out using Gunter chains, but I suspect the engineer’s chain would have been used more often. I have seen survey plats from the territorial and colonial days that are demarcated in chains, links, and rods; but I have not seen any old highway or railroad plans denoted in anything other than 100-foot and 1000-foot stations. They may well exist . . . I need to get out more. Robert

Arround 1978 I was on a survey crew resurveying a county road in California using a Electronic Measuring Devices (EDM). There were two previous surveys. One done in the late 1880’s or 90’s with 66’ chains. The other done sometime after 1900 using 100’ chains. There was a descrepency between the surveys. When we started we didn’t know which one was right. Turned out the first survey was correct. The crew working on the post 1900 suvey had lost count of the number of chains they pulled.

[DSchmitt]

Typically, a profile will have references to vertical curves only. Vertical curves ease grade separation at the top and bottom of grades. Vertical curves, like curves for horizontal alignment, are defined in degrees, minutes, and seconds of angle. The lower half of a circle would represent a vertical curve at the bottom of a grade, and the upper half of the circle would represent the vertical curve at the top of a grade. Horizontal curves are typically shown on the plan sheet, not the profile sheet. If a plan and profile are shown on the same sheet, a separate curve table for horizontal curves is usually referenced. Add Quote to your Post

A plan is a layout drawing. drawn to scale. It shows the horizontal curves and also often includes a profile.

A Track Chart is a straight line representive diagram of a railroad. It does not show horizintal curves and may or may not be drawn to scale

asg-trackchart2_zpsdx9udepy (1) by Donald Schmitt, on Flickr

Railroad Track Chart with profile and curve data

aL2a-3-lg_zpsvifpdazt by Donald Schmitt, on Flickr

Highway plan, profile and superelevation- superlevation diagram shows profiles at each outside edge of “travel way”