ACTUALLY Santa Fe had their own maps created by a private service which flew over the possible routes and created 1’ - 100 ft contour intervals. These were then provided to field parties and were used in locating the ’ final line’. All government Bench Marks and and brass caps with land line ties were on these 1’= 100 maps. We surveyors were able to very accurately establish elevations and alignment with this current information in very remote and pristine wilderness.
KP’s not the only one enjoying what you have to say about the line change. Even though I’m an EE, the “obscure” details are quite fascinating.
- Erik
diningcar, the part about aerial photography caught my attention.
Do you perhaps know the name of the firm which did the aerial surveys? My family’s business used to operate next door to Pacific Air Industries in Long Beach, California. PAI was founded early after World War II by a group of ex-Navy pilots and did a lot of such work around the West. It was later bought out and became Teledyne Geotronics.
garyla, first a correction-addition to the details of the maps we used;
the maps we had in the field were 1" = 100’ horizontal scale and the contours were at two (2) foot intervals. Those of you who use such tools can quickly agree what substantial help these were.
A California company flew the routes and made the maps but I cannot furnish their name.
…One more question: {Well, maybe two}…
How can an aerial {one dimension} photo supply enough data to create a Topo map…?
And how is an accurate Topo map really created…To record the rise and fall every two ft. of a landscape, must require a lot of input data. And somehow that has to be gathered…and to have it over a wide expanse of desert open space…??
Modelcar,
The process is photogrammetry of which I have little knowledge.
By the way, this was not desert but a mountainess volcanic area with basalt and volcanic cinders overlaying sedimentary sandstone and limestome. Very difficult to determine what might be down below so we had to drill test holes to determine what slopes(s) to create; and we were still surprised after we opened up the large cuts to find we must re-engineer and lay the slopes back.
Those who looked at the MK film can get some idea of the many problems-surprises we had to deal with.
Yes, I thought about that when I wrote “desert” as the landscape…I noted in the excellent film / video of the construction, that was posted, the ROW was put thru nasty rock cuts and plenty of fills, etc…
Thanks much to the various posting forum members for this interesting and well documented railroad archeology tutorial. You don;t have to be an Arizona resident or ATSF fan to find all of this quite interesting.
Dave Nelson
Oh, yeah - that would be just about perfect for the task, considering the distances and grades involved. Actually, for the steeper slopes a 2 ft. contour interval at 1’’ = 100’ scale might be too close - 5’ or 10’ might be more appropriate. For example, if it’s a 45-degree slope that rises 100’ in 100 ft. forward, that would be 50 of those 2-foot contour lines in the 1’’ on the print - they’d be 1/50 of an inch = 2/ 100th’s = 0.020’’ apart, which is pretty tight.
Even today, until recently for residential subdivision and medium-size land development work - say, from 100 to 500 acres, or about 1/4 to 1 square mile - in this eastern Pennsylvania area a horizontal scale of 1’ = 50’ and a 2’ contour interval was quite common. But after some problems with accurately estimating earthwork quantities and planning road connections, about 15 years ago my current employer started asking for 1 ft. contour intervals for mapping for that purpose, which was uncommon then and is still so to some degree. Even there, we specify and ask for or will accept 5 or 10 ft contour intervals for the steeper slopes, to keep the prints legible and usable. Of course, now that those maps are all digital, we instead simply ‘‘turn off’’ or ‘‘freeze’’ the smaller contour interval ‘layers’ when working with the resulting maps, unless until we actually need that level of detail someplace.
- Paul North.
Dave,
If you’re interested in some follow-up reading on this huge, remarkable project ($22 million used to be a lot of money!), I would suggest any of the following:
Pacific Rail News, September 1992, pp.18-23
The Warbonnet (Santa Fe Ry. Hist. & Modeling Soc.), 1998/#2, pp. 19-31
Railroads of Arizona, Vol. 4, by David Myrick, pp. 245-54
Enjoy.
-garyla
Some very quick, brief, and hence summary and not totally comprehensive answers to Quentin/ modelcar’s questions above
-
Quite correct, Quentin - a single photo can’t - at least 2 are needed, with significant overlaps, like more than 50 %, so that almost each point is shown on at least 2 photos. That is done by taking many photos a few seconds apart, almost like a movie camera on very large film. They are/ were then viewed separately through a ‘stereoscope’, with 1 eye looking through each lens at each photo, to create a ‘3-D’ effect, which the technician - now a calibrated machine - uses to locate and plot the contour lines.
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Remember basic geometry - “3 points - not on the same line - can define a plane” ? As long as the location and elevation of at least 3 points in each photo are k
I’m a little late to this cracker barrel.
When I was last out in Arizona in 2008, my brothers-in-law, experienced 4WD/Jeep drivers, and I did some navigation of the old Santa Fe Transcon.
You missed the good ones.
Way on back off the roads is Fairview Tunnel, the ONLY tunnel on the entire Santa Fe Transcon until it was bypassed by the Crookton Cutoff and the rebuild of the Peavine. And then there’s the old line west of Prescott, with 3.5% grades.
When I have more time and/or figure out if I can upload images here, I’ll come back with some photos to share.
This tunnel is usually called the Johnson Canyon tunnel and is the one I mentioned earlier where high/wide loads could not clear and had to be sent against normal traffic.
Also, there were additional tunnels: you limit it to the Transcon so I assume you are talking about the Santa Fe after the Belen cutoff was opened in 1908 and Raton does not count in that case. The short tunnels on Cajon pass certainly qualify even though they were recently eliminated with the triple tracking project. And there remains the tunnels at Nelson, 31 miles west of Seligman.
Yes the abandoned line west from Prescott is worth a look but is currently substantially restricted for on road vehicles, and some off road vehicles restrictions also apply.
Thanks for additional info Paul…and yes, I’ve seen the “X panels” right here in our addition. Some time ago, several manhole covers contained large white color “X’s”…and someone had noted they were for aerial survey.
…I’m sure most of us on here will be happy to see additional photos.
There’s a danged good reason vehicles are restricted on the stretch between Skull Valley and Iron Springs/Prieta: It’s entirely possible to inadvertently drive right off a 120-foot-high abutment for the now-missing Ramsgate Trestle. The locals say someone has managed to do it. Once. And approaching the abutments from either direction, it’s not as visible as it should be, even on foot.
The aforementioned tunnel (along with the adjacent trestle before it was filled in) has been referred to as both Fairview and Johnson Canyon; we managed to duplicate a few Santa Fe publicity photos from the area with a Jeep Cherokee subbing for the Super Chief… and, yes, the “only tunnel on the Santa Fe Transcon” did indeed depend on your ability to ignore Raton Pass and other such routes.
The line now referred to as the Transcon-- SFe LA to Chicago via Amarillo-- did have just the one tunnel (Johnson Canyon) for a few years after it was completed.
Actually when the Jonhson Canyon tunnel was complete, 1882, the Transcon through Amarillo did not exist. That line through Belen was open for operation in 1908.
In 1882 the route over Raton pass was the only "transcon’ connection to the east, and of course the Los Angeles connection occured in 1885 via Cajon Pass.
So how does the Cajon Tunnels fit into this thought back in the era under discussion…? Wern’t these bores on the “Transcon”…
Just to clarify: nothing there contradicts what I said.
The Cajon tunnels were built circa 1913, so from 1908 to 1913 “the line now referred to as the Transcon” had one tunnel. (The Nelson tunnel dates from … 1923?)