Monday, July 24, 2006

Engineering Notes on the Sierra Nevada Line

From: "Larry Mullaly"

I recently came across some primary material on the Sierra Nevada portion of the Overland Route (see below) that I thought might be of interest. Although the anonymous writer is generally critical of CP engineering standards, the he seems well versed in such matters and makes insightful comments. Any ideas as to the date of the document and the identity of the author would be welcome — as well as critiques of his critique!

—Larry Mullaly


Comments from An Anonymous Engineer: 

Pino to Reno    

In October, 1998 during a visit to the National Archives in Adelphi, Maryland, I came across a set of hand written notes at the bottom of a box of documents: R(ecord) G(roup)48, Secretary of the Interior Lands and Railroads Division, Railroad Packages Number: 187. The notes, written in ink in a small hand, are unsigned and undated. They provide interesting technical perspectives on portions of the Overland route. My transcription covers only part of this material.  

Larry Mullaly  


If the 6 degree curve to left stat[ion] 669+30-672+85 had been omitted and curves on each side joined by a tangent from one to the other [side?] of this curve, how much would it have increased work? There is too much timidity about being willing to take work to get good line.  

Clipper Gap.            

The several ... curves west of Clipper Gap station are needlessly sharp. Even tangents substituted for some curves would not make the work heavy or much increase it.

Series of reversed curves on 43rd mile could be made much easier. Tangents in place of some of them would not make heavy works. Series of reversed curves on 46th mile could be much improved without making heavy work. The same occurs on the 50th mile curve 9 degrees R. Stato. 970-980 could be replaced by tangent without very great cost and 6 degrees R. at Station 2660 might even have been omitted. Of course to ease curve is less expensive.  

Colfax, Gold Run, Dutch Flat, Alta.            

The road west of this is generally well built so far as culverts, bridges, and embankments are concerned, but the location is throughout on a very contracted vision, the extreme of curvature being adopted to save cost, to the great injury of the commercial value of the road.            

The line examined today (from Auburn) lies in shale formations affording no material for ballast, and the shale rock which has been used in surfacing the road is all disintegrating into clay, grassy [?] and so retentive of moisture as to be unfit for ballast. The cuts in some cases [are] rather narrow. The water tanks entirely too small. [Penned into margin] Note: Compare the locations on the C.P. road with that on the Penna. railroad in valley of Juniata, or that of Pittsburgh and Columbus R.R. between Pittsburgh and Steubenville or between Steubenville and Dennison. See what prodigious work was taken by these latter roads to get good alignment: high embankments and deep cuts to get curves of radii from 957 feet to 1910 feet. A curve as sharp as 957 radius was never used unless more demand existed for it than is on C.P. very often considered a justification for much sharper cures.  

Shady Run            

Bad locations on the 71st mile, stations 3720-3760. Line between this and Alta has same objection as before, too much curvature and needlessly sharp. Occasionally, however, on this line there are points where line is well laid showing less timidity of design.            

7 degree curve east of Shady Run is an instance where an easier curve could have been used at small increase of cost leaving balance of line undisturbed bed. There is a tangent on each side of this curve, and by simply lengthening the curve (that is, increasing the radius) this [could?] have been obtained....            

The 7-degree curve at 117th milepost is needlessly sharp.            

It seems to me the engineering over the Sierra is altogether too much cramped, and that too little attention was paid to the effect on the operating of a road by such a constant use of sharp curves. It is claimed the work is very expensive and as our evidence the tunnels are very numerous. True, there are many tunnels, but after all, the total length of tunnels is small, less than on Baltimore & Ohio road or on Penna. Road, and considerably less than on road between Pittsburgh and Columbus. (Total length tunnels on C.P. was 6262 feet of which.... I cannot think of a proper effort was made for a good location such as would have been in the long run, economical).  


A very great detour is made between Reno and point 5 or 6 mile below, when line approached river again. This is totally wrong. Line should have been straight from point west of Reno to upper end [of?] narrows. It is said present line was taken to avoid low ground, which is a great mistake. In locating roads we must meet and overcome difficulties, providing it can be done with any reasonable outlay, not dodge the [problems?].            

In narrows below this point curvature is needless[ly] great and sometimes almost shameful.            

For 15 miles ... profile not furnished, but cannot reconcile myself to location. Is it proper or necessary to bear away from river so much and make undulations?            

The two curves near 168th milepost are needless even with present grade. It is plain there should either have been less curvature/no reverse, or the grade should have been easier. My ideas is ...[that?] ameliorating should have been secured by taking the requisite work.            

Locations from about Station 3510 on 172nd mile to about 3600 is bad. This undulation could have been avoided at a very light increase of cost and the curvature diminished a same time. Part of the sharpest curvature here is begotten by keeping up the grade. A change in location has served throughout undulating, making an easy grade. Shorten the line, reduce the deflecting, and lengthen the radii of curves with but little additional cost...            

The line down Truckee valley partakes of the general character of the balance of the locations. It is penuriously cheap in first cost, alignment and grades being both sacrificed to attain this. Distances are often needlessly increased and the curvature caused largely in excess of what is required by the valley for a line from moderate cost. The commercial value of the road is diminished and the cost of operating it is increased. I think the whole line bears evidence that a contest for time had much to do with the locating. [Text continues].