Railroad Map Survey Nomenclature
From: "Sprinkler Service & Supply" sssprinkler1@earthlink.net
We are trying to understand some of the nomemclature used on the SVRR Extension Folsom to Maryville Map, 1857. The railroad bed bends are noted by an angle measurement with a degree at the apex and numbers at the ends of the radii such as 429+60 and 432+10. Obviously these notes refer to the degree bend in road bed, radius and length. However, we are not educated in how to read the surveying notations. We would like to plot the line against present day street maps. ...
Kevin Knauss
Sprinkler Service & Supply, Inc.
Carmichael, CA
posted from CPRR Discussion Group at 1:29 PM
12 Comments:
From: "Wendell Huffman" wendellhuffman@hotmail.com
The "429+60 and 432+10" are undoubtedly survey points along the proposed track centerline: engineering station 429 + 60 feet, and station 432 + 10 feet. There were engineering "stations" every 100 feet, so those points would be 42,960 and 43,210 feet from the initial point. It sounds from your description that those points are beginning and end points for a curve – generally noted as TC (tangent-curve) and CT curve-tangent, or BC (begin curve) and EC (end curve). The degree doubtless refers to either degree of curvature (the way curvature was defined), or the degrees through which a curve turned. It should be real easy to figure which it is. Degrees of curvature very rarely went above 15 (or so) degrees on a railroad, while a value below 10 would be much more common, it it is referring to degree. I'll have to dig out a copy of that map to say for sure. Railroad curves in 1857 will be either simple or compound. There were no transition spirals in those days.
—Wendell
From: "Bill Anderson" bill@fedshra.org
To add to Wendell's comments, the extension of the SVRR was the California Central. Intended to reach Marysville, the line ended at Lincoln.
Since you are a neighbor, have you visited our Folsom Railroad Museum?
We have local railroad information to share.
See us at www.fedshra.com.
Bill Anderson
FEDSHR
From: "Wendell Huffman" wendellhuffman@hotmail.com
The degrees on that map refer to degrees of curvature. Generally, the degree of curvature is the central angle for a chord of 100' (though some railroads based it on an arc or 100', while others broke the 100' chord into four 25' chords). The degree of curvature is equal to the angle of deflection between two adjacent 100' chords (which is twice the angle of deflection between the adjacent tangent and the first or last 100' chord).
I presume you know that the SVRR Extension railroad was never built. What was built was the California Central RR. The alignments may be different.
—Wendell
From: "Sprinkler Service & Supply" sssprinkler1@earthlink.net
Thank you!
I have read that the CCRR built that extension. The map I received from the RR museum is titled SVRR, 1857, railroad as located. And there are a few anamolies from that map and other sources I have seen regarding the alignment. Your information is prompting me to go back on brush up on the old math skills.
— Kevin Knauss
From: "Sprinkler Service & Supply" sssprinkler1@earthlink.net
Bill,
Thank you.
I have talked to the curator about viewing some of the old maps. Our preliminary research so far has produced some fun insights about the history of the area and how quickly development can cover it over.
—Kevin
From: "Sprinkler Service & Supply" sssprinkler1@earthlink.net
None of the degrees are above 3 which lead me to believe that the number indicated elevation change. In addition, some of the markings are on seemingly on straight portions of track. I have ordered "The railroad engineers practice" that details notations when laying out track. After I study up, I'll probably have a better understanding.
—Kevin
From: "Bill Anderson" bill@fedshra.org
I messed up again!
Our website is www.fedshra.org.
—Bill
Where does one order "The railroad engineer's practice?"
The railroad engineer's practice
Thomas M. Cleemann, 1880 - 75 pages
The railroad engineer's practice: being a short but complete description of ...
Thomas M. Cleemann - 1892 - 190 pages
Paper copies.
From: "Wendell Huffman" wendellhuffman@hotmail.com
Robinson noted several 6 degree curves on his map: on either end of the American River bridge, and where the line curved over China Hill and down along Plummer's Ravine. That figure is quite appropriate for the geography of that district. Where the country opened up, curves shown on the map are broader 1 and 2 degrees.
A "location" survey is an engineer's line as staked on the ground. It only relates to where a railroad was actually built if the railroad was built on the located line without alteration. Note that Robinson's map of the SVRR Extension is dated September 1857. James P. Robinson was the superintendent, and at the time this map was drawn, chief engineer of the Sacramento Valley Railroad. Construction of the California Central was commenced northward from Folsom in May 1858. Any number of changes may have been introduced between the date of Robinson's location and actual construction. The California Central had its own chief engineer: initially William S. Watson, and after April 1858, Theodore Judah. They would have built on their own "located" line.
The only map I have handy of the California Central as built is Samuel Montague's February 1864 map of the location of the first section of the Central Pacific – from Sacramento to Newcastle. (Note: the CP "location" as shown on this map runs all the way to Newcastle, but as of the date of the map, the railroad itself only extended 14 miles from Sacramento.) Montague's map shows the Cal Central only incidentally, but it is likely trustworth map as Montague had been Judah's successor as chief engineer of the CC, and that railroad had been completed to Lincoln in 1861, well before the date of the CP map. (I think there is a link to a copy of that map on this CPRR.org website.)
While Montague's map does not mark and describe curves, as does Robinson's map, it shows the constructed location of the CC somewhat differently than Robinson's line, especially north of Secret Ravine (where Roseville is today). This difference can be easily verified as the existing UP railroad north of Roseville has evolved from the CC's railroad. It is built on the CC's roadbed. It can be compared with Robinson's map. It also shows some variation south of Roseville, along what I believe was Plummer's Ravine.
(continued below)
I suspect for your project, you are only interested in the section between Roseville and Folsom. In that district, the various lines are probably fairly much alike, at least across the American River and over China Hill. Judah's original 1854 location survey for the SVRR extended 31 miles, or 9 miles beyond Folsom. Judah located the bridge at the natural place for a crossing, and his line over China Hill and down to Plummer's Ravine most likely followed the most promising route afforded by nature. Thus, no matter how many surveyors visited the site, they would probably all arrive at a similar solution.
The California Central did indeed build a portion of railroad planned by the SVRR. Indeed, the president of the CC, Charles Lincoln Wilson was the ousted president of the SVRR, and was intent on fulfilling his initial ambition of building a railroad to the head of the Sacramento Valley (thus that railroad's name). Robinson's June 1857 location survey northward was an immediate response to Wilson's organization of the CC in April 1857. The SVRR was not at first willing to abandon its northward ambition to Wilson and the CC. Just how closely Robinson followed Judah's 1854 location over those first 9 miles northward from Folsom could be fairly easily determined, since Judah's inventory of "curves and tangents of the first 31 miles of the Sacramento Valley Rail Road" exists at the California State Archives. It can be compared with Robinson's map. My recollection is that Judah's descriptions of curves are given in radius, not degrees. But nearly every railroad engineering book will have tables for converting those figures.
It is also very likely that the CC's location was also close to Judah's 1854 line since Watson had been Judah's assistant when the 1854 location was established, and Judah would likely have favored his own 1854 line after he joined the CC in 1858. However, it is possible that Robinson "improved" on Judah's line (after all, Robinson didn't like Judah). Too, Watson may have made his own "improvements" when he made the initial location for the CC (Watson had a mind of his own). And, Judah may have made further "improvments" to the line when actual construction began. In any event, there certainly appears to be a minor difference between Robinson's 1857 line and the railroad as built between the site of Orangeville and the site of Roseville. The as-built line (of Montague's map) shows four curves along what I think is Plummer's Ravine (about half way between Orangeville and Roseville), while Robinson showed that all tangent.
If you haven't already done so, you might look at the California State Archives for a list of the CC's curves and tangents. It would be wonderful if one existed. There is a January 1859 "Report of the Chief Engineer" of the California Central. However, while it provides grades, and identifies features (like China Hill and Plummer's Ravine), it ignors the important issue of curves and tangents. Generally curves were listed separately (now, if it is presented as Montague did the CPRR curves in 1864, it won't be helpful, as that merely gives the total of various curvature). I would also suggest you try to locate arial photographs of the area. The old grade probaably showed up until fairly recent years. I remember old Orangeville Avenue, which ran on top of the CC line up and through China Hill. The cut was very narrow, with nearly vertical sides. Sometime in the last 30 years that has been completely rebuilt, the cut obliterated, and for all I know, the road may even have a different name. Sic transit.
—Wendell
From: "Sprinkler Service & Supply" sssprinkler1@earthlink.net
I just went to Amazon.com and there are several bookstores that stock reprints of the book.
—Kevin
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