Modelcar [snip] 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....??
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....??
Some very quick, brief, and hence summary and not totally comprehensive answers to Quentin/ modelcar's questions above
1. 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.
2. 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 known to within a couple tenths or even hundredths of a foot, the technician can match them up enough to establish the 3-D relationship between the successive photos and the terrain.
Often, 'panels' of white 'X's and 'T's are placed in the field before the aerial photos are taken, so that they appear in the photos - you may have seen those along roads from time to time. They are accurately located by survey instruments as input data to support the mapping/ plotting operation.
If such panels are not used, certain other 'photo-visible' points can often be used instead - utility poles, manholes, corners of patios and sidewalks, and parking lot stripes, etc. are favorites, although those might have been scarce out there for the Santa Fe's project. Then, the technicians can 'bridge' between the successive photos by using common points - essentially analogous to graphically solving a series of simultaneous equations, as long as there's enough data to do that.
For a project of this size, I would estimate that a minimum of about 3 to 5 points per square mile mapped would have been required to be located in the field. As quick comparison, a few years ago both Lehigh and Northampton Counties were aerial-mapped at the same time for 1'' = 100' scale maps and 5' contour intervals for GIS maps - and I understand that only 65 points or so were needed to provide a sufficient number of 'control' points for several hundred square miles of farmland and cities that are included within them.
- Paul North.
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.
LNER4472Way 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.
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.
Paul_D_North_JrRemember 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 known to within a couple tenths or even hundredths of a foot, the technician can match them up enough to establish the 3-D relationship between the successive photos and the terrain.
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.
Quentin
LNER4472 When I have more time and/or figure out if I can upload images here, I'll come back with some photos to share.
.....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.
timzThe 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.
LNER4472 and, yes, the "only tunnel on the Santa Fe Transcon" did indeed depend on your ability to ignore Raton Pass and other such routes.
So how does the Cajon Tunnels fit into this thought back in the era under discussion...? Wern't these bores on the "Transcon".....
diningcar timzThe 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.
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?)
diningcar, et al (8-14):
Aerials have been studied, but they have been inconclusive regard direction of travels and any reversals of biases. It is hard to comprehend biases change just through crossovers and not some type of physical way of getting one track over or under another. My list of to-dos has just expanded (i.e., to visit Arizona and New Mexico). It has been so long since I had an accurate mental overview of the Transcon in those two states everything over there is foggy in my mind.
Anyway ... While coming into Seligman, AZ this past quick trip, at CP EAST SELIGMAN a staging area of some sort was observed and photographed.
These items struck me as rail joint insulators, but I don't know ... I never had seen a pile of such before.
There has been some mention in this thread about the old Cajon Pass tunnels. The any that need a visual, the below photo of where the tunnels use to be is offered.
About mileposts ... Am I correct in understanding that the 1960 relocated Arizona line does not have mileposts suffixed "A" but only the last one, M.P. 418A, which is the second M.P. 418, and from M.P. 418A to M.P. 419 it is only a distance of 3016 ft.?
And, then there is Ash Fork ...
The below photo looks east at the once double-track Los Angele-Chicago thru-line, with only one track remaining that eventually ends up in Phoenix, AZ. View looks east towards Chicago.
Aerials of that east side of Ash Fork above show where a removed wye kind of overlaid another removed wye! I have never seen anything like that before!
Your reply to any of the above, diningcar, surely would be most enlightening.
Thanks,
K.P.
----------------------------------------------------------------------------------------------------------------------------------- K.P.’s absolute “theorem” from early, early childhood that he has seen over and over and over again: Those that CAUSE a problem in the first place will act the most violently if questioned or exposed.
KP, the following will attempt to answer your inquirys(s).
The entire Transcon from Barstow to Belen now has CTC which permits the DS to run all trains, on either main line, in any direction, crossing them over and back by controlling the signals and power switches, and using radio communication. The 44 mile line change instituted this with reverse # 24 crossovers at Williams Jct, Perrin, Double, Eagle Nest and at Crookton.
Santa Fe's practice has been, where there is a substantial variance from a 5280 mile to use the A suffix and then revert to the existing Mile Posts. In this situation the new line is longer than the former by 3016. The 'A' designation is also used where the two main lines are not parallel and the most recently constructed line will have 'A' MP's. Near to you, as an example, would be the Ash Hill location east of Ludlow, CA.
I can only speculate about the material stockpiles at Seligman. The old high star switch stands would seem to have been salvaged from yard tracks being removed. If this assumption is correct then it would likely follow that the other materials came from similar projects (or the same one) and the stockpile is at a convinient location to store material where they may be under some security and be picked up later.
I see two wyes at Ash Fork about 1/2 mile apart but do not see the 'overlay' you mention. Perhaps the two I see can be explained by knowing the history there. When the line to Phoenix from Ash Fork was originally built (1890's) it connected to the Santa Fe main line (single track then) at the east side of Ash Fork. As is evident, the Phoenix line now leaves Ash Fork at the west end of town. So it is possible (likely) that the wye at the east side was located to facilitate the reversing of Phoenix equipment. It could have served the additional purpose of being the main line wye.
The wye located north of and opposite the main body of the Ash Fork yard was the 2nd wye and had the Stock yards located along it. This wye appears in the 1916 Ash Fork Station map (1" = 100') while the other one does not; and the Phoenix connection is at the west end of Ash Fork on the 1916 map.
Assistance from other forumists is solicited and follow-up questions welcome.
K. P. Harrier [snip] These items struck me as rail joint insulators, but I don't know ... I never had seen a pile of such before. [snip]
[snip]
They're insulators, alright, but not for rail joints - they fit between the rust-brown spring clips in the 2 bags at the upper left of your photo, and the rail, so as to better insulate the rails from the concrete ties and hence from each other for proper functioning of the signal system. I'll see if I can find a link or close-up photo of them in use so you can see how they work.
EDIT: P.S. - Those spring clips look like the U3220 by Unit Rail Mfg. as I suspected, and here's the link to their webpage for clips, insulators and related products:
http://www.unitrail.com/concrete_steel_ties.html
- PDN.
diningcarThe 'A' designation is also used where the two main lines are not parallel and the most recently constructed line will have 'A' MP's. Near to you, as an example, would be the Ash Hill location east of Ludlow, CA.
diningcar (8-19):
Thanks for replying so quickly. You gave me much to digest.
About that "wye" situation in Ash Fork, AZ ... a MapQuest link to an aerial follows.
http://mapq.st/h/2-M2ZU
The left part of the wye on the aerial's right looks like it goes through another wye on the left, and continues westward on an abandoned right-of-way to the west part of town.
That abandoned right-of-way goes through even a third wye on the west side of town before it realigns with the traditional abandoned Transcon line on the west side of town. That third wye is visible by moving the map leftward (west) a few thousand scale feet.
The history of lines is a fascinating subject in itself, if that history is retrievable. Like in Cajon Pass here in California. Many railfans and railroaders don't know the present three-track line railroad west of CP CAJON up until the 1940's was on the camera side of the below bridged creek.
Anyway, let me digest the rest of your reply. The forum is fortunate to have someone like you that actually worked on the Arizona line relocation and is willing let his experience and knowledge be tapped!
Thanks so much.
Paul D. North, Jr. (8-19):
That was something new (at least for me) about insulating clips. I wonder if they act is a wear cushion?
For years the railroads have done without them (at least around here). So, it would be interesting to find out the logic in them now.
K. P. Harrier [snip] That was something new (at least for me) about insulating clips. I wonder if they act is a wear cushion? For years the railroads have done without them (at least around here). So, it would be interesting to find out the logic in them now. K.P.
Probably only indirectly. Wear at that point in the assembly - at the edge of the base of the rail and the mating surface on the railclip holder, and on the top corner of the rail base - has usually not been a problem. Instead, that wear has been mainly under the rail seat area, where most of the weight and flexure occurs. Towards the bottom of the linked page, you'll see several plastic pads, abrasion plates, and and abrasion pads which are much larger for installation there to address that problem, although one - the "U1036 3-Part Pad Assy" - does appear to also include the insulator as one of those parts.
If the railroads around there have been using concrete ties without the plastic insulators for years before as you say, the obvious and rational explanation - to me anyway - is that those railroads have recently found or concluded that the concrete ties by themselves are not reliable enough insulators to keep the rails electrically isolated as much as they want. Whatever the electrical insulation performance of that system has been there in the dry SouthWest in years past, with the recent higher traffic levels and dependable signal system performance becoming more important than ever in keeping traffic fluid and maintaining capacity by not having a lot of 'false reds' creating bottlenecks of 'Restricted Speed' running, so the conclusion may well have been to start using them, despite the added cost, time and complexity of installing them, in the interest of more reliable signal system performance.
The other possibility is that with aggressive minerals out there, the steady electric current of the signal system leaking through the ties may have caused a galvanic reaction and corrosion problem - most likely in the concrete ties - especially whenever it rained, even if infrequently. The insulating pads would cut off that current and reaction, too.
timz and KP:
timz is correct about the X designation, my memory failed once more. Thanks timz.
KP, your aerial photo is better than mine and I now see a possible wye on the north side of the track which lies westerly from the more prominent wye, both of which are east of Doublea Ranch Rd.
Also looking at your Mapquest photo the connection of the Santa Fe, Prescott & Phoenix line may be shown on the south side of the Santa Fe main and paralleling the current City of Ash Fork street that connects to Doublea Ranch Rd. If indeed this mark on the earth is the remains of the connection between the Santa Fe and the SFP&P then it also appears that there was a wye created here too as another mark on the earth seems to make an easterly connection. If these marks are the wye used to turn the Phoenix trains then the wye(s) to the north had another purpose.
Ash Fork was a busy terminal with a large station grounds. Prior to 1960 helper service emanated here and so a substantial mechanical department facility and staff worked here.
I was able to access a 1916 Santa Fe station map, 1' = 100', and it shows only the one wye track located in the middle of the station grounds. The wye and overlay shown to the east on KP's aerial are not depicted on this official map.
Also, this 1916 map shows the Prescott - Phoenix line connection at the east end of Ash Fork with no wye connection eastward to the Santa Fe main tracks.
Transition Mystery Solved!
A brief review: Up into the 1950's in the WEST Santa Fe trains were RIGHT-track running under "double-track" rules, with each track signaled in only one direction. In the EAST, trains were LEFT-track running. The magical transition point was a number of miles west of Ash Fork, AZ, where one track went over the other.
Old natural crossover area
That magical point of transition disappeared with the big line relocation in 1959-1960. So, where is the transition point today? In Winslow, AZ! But, the situation is very different because one track does NOT go over the other.
In Winslow, there is a fueling facility, with what looks like four tracks on aerials. Any track can be used and it is slow going through the area. Left biased trains from the east end-up right biased as they head west and vice versa.
Winslow, AZ fueling facility
The fooling difficulty was that between Seligman and Winslow, AZ the line was CTC'ed in conjunction with the big line change, and the Dispatcher could transition trains anywhere between those points. But, the key point IS Winslow! That is where trains passing through go the slowest, and can be in a logjam environment. Even without any biases to deal with, any fueling facility is a slow going, often a logjam type place.
So, Winslow, AZ solves the transition mystery!
A lot has transpired since the Williams-Crookton line change which became operational 12-19-1960.
Now the Transcon is all CTC between Belen and San Bernardino ( much more CTC than this but this is the current subject). So the DS can have any train operate on either track no matter which direction it is going. With CP's every 8-12 miles trains pass, or meet , wherever the DS chooses in his quest to expedite priority trains.
I have more info about Ash Fork than in the previous posts.
When the Valley of the Sun began shipping fresh fruits and vegetables to eastern markets they of course were shipped in cars refrigerated with ice stored in bins at each end of the car. As the ice melted it had to be replenished so ice plants were established at appropriate locations. Ash Fork was one of those locations. But there was the problem with the connection at the east end of Ash Fork since trains entered the yard with a west movement, while their destination was eastward.
That is why the Phoenix line was relocated to the west end of the yard. The ice plant and ice loading platform were built on the north side of the existing yard so that the refigerated trains, through a series of crossovers, could pull along the ice loading docks and then leave Ash Fork with an eastward move. The wye track located north of the Transcon and east of the yard allowed the Phoenix line engines to be turned for return to Phoenix and the Transcon locomotives to be coupled for the continuing eastward move of the reefer train. Of course the wye would have been used for other moves as necessary such as turning the helper movements to Williams.
diningcar (2-10):
Yes, a lot HAS transpired since the Williams-Crookton line change!
The "Transcon" is now all CTC, and in some places triple-track is present, as in San Bernardino, CA at the far western approach to Cajon Pass.
Back when you surveyed and plotted the Williams-Crookton line change in Arizona, AT&SF was basically a double-track railroad, so converting that area back in 1959-1960 to a two-track line was sort of a novelty.
Traffic volumes have at least tripled since your work in 1959-60. No wonder BNSF CTC'ed and basically two-tracked the whole Los Angeles-Chicago line.
Have you, diningcar, visited your old haunting ground in Arizona of late? If you have, undoubtedly you said to yourself, "I actually plotted this! Wow!" What an element of personal satisfaction you undoubtedly received, something probably none of us others at the forum will ever have.
Now that my final personal mystery that stemmed from your past work has been figured out and posted about, I hoped your satisfaction has been broadened.
Take care,
Mr. Harrier, thank you for your kind and very generous words. There were more than 60 engineers of various types working on the Williams-Crookton line change. Yes I have been back and have conducted tours for friends before the 9-11 events caused BNSF to restrict access. It was a grand experience for a young man.
The original line (would now be called Main 1) was approximately the same length after the line change. But the circuitous second main was shortened about three miles.
Tried to open the MK video but got a message that it had been removed. I have seen this video a while back and will try to locate the source and post it here.
Now It Is Really Solved!
On February 10, 2012, "Transition Mystery Solved!" was posted. Yesterday, March 5, 2012, another natural crossover was discovered by K.P. that puts a different slant to the matter. It is unbelievable that K.P. missed it in the first place ...
EAST OF ASH FORK NATURAL CROSSOVER
Previously ...
West of Ash Fork Natural Crossover
So, the OLD, pre-1960 line was basically right biased, except for a stretch of left biased trackage on either side of Ash Fork, AZ.
With old and new lines, Winslow, AZ was still the transition point, with biases west of Winslow generally right handed, whereas east of Winslow was left handed. That must have been especially pronounced in Automatic Block Signal (ABS) days of "Double Track" (as opposed to todays "two-tracks").
In the late 1970's / early 1980's K.P. personally saw the left biased route EAST of Winslow, obviously evidenced by the then proliferation of cantilevered signal bridges compared to mast signals used for right biased trackage west of Seligman.
It is unknown what type of signaled track arrangement was used in steam days, BEFORE the Winslow fueling facility for diesels came about. But, it probably was the same. The logic in NOT having a flyover in the Winslow area to keep things fluid and trains moving may have been that everything was slow going anyway, as it probably was an important re-coaling and/or steam engine trade-out stop.
Un-Solving the 'Really Solved' to Solve It
Got that doubletalk?
An aspect of this topic was mentioned in the thread "Sunset Route Two-Tracking Updates." BNSF6400 responded with two key replies in that thread. I found BNSF6400's reasoning and sources quite credible. He indicated the east of Ash Fork natural crossover was NOT a natural crossover at all, but that it only had that appearance.
The posts by BNSF6400 are on page 161 (March 6, 2012) of the "Sunset Route Two-Tracking Updates" thread.
So, right running double-track from the west (with Automatic Block Signals) reversed to left running at the natural crossover WEST of Ash Fork, and remained left running all the way to Belen, NM. Here and there are geographic locations that make left-running practical.
With the big 1959-1960 line relocation, the Seligman-Winslow, AZ trackage was CTC'ed, and in that manner biases got reversed, and NOT with a natural crossover. So, the February 10, 2012 post on this page 4 titled "Transition Mystery Solved!" was basically right.
In the "Sunset Route Two-Tracking Updates" thread, ccltrains mentioned a video on the AT&SF reroute. Cacole (on March 8, 2012, page 162) in that thread found a link to such a video, which link is duplicated below for interested parties.
http://www.youtube.com/watch?v=qsllGIKfPn0
The video is short of 30 minutes long, and is well worth watching.
Although I rarely vacation to Arizona I have found this discussion quite interesting. I love abandon train tunnels and all the more better if you can visit them through a national park. I have never heard of the Johnson Canyon tunnel. It must have been in a very remote place as there doesn't seem to be any photos of it when it was active.
I know this post is quite old, but I visisted the area in question 9/13/15 and thought you guys might enjoy a picture of the previously mentioned tunnel! I have video of the approach as well, I'll post that after I get it uploaded.
etro (9-14):
First, welcome to the forum.
Your post initially baffled me, as the tunnel’s location was unknown. The best I could determine, the tunnel is somewhere between Williams and Ash Fork (AZ). The double-track line between those points had the appearance of paired track, and each main took a different route. With the line relocation of this thread (1959-1960), both mains between Williams and Ash Fork were not needed. The main that Santa Fe abandoned was the tunnel route you mentioned. The surviving main continues today and goes southwardly from Ask Fork to Phoenix.
Have I, etro, surmised correctly so far?
A video link is below of getting to and going through the tunnel, though the video I don’t think pinpoints the tunnel location.
https://www.youtube.com/watch?v=9qF0stmJuf0
For your information, as well as the rest of the forum, in researching the tunnel, one website (address unknown) totally locked up my computer, and I had to turn it off. My computer is protected by Deep Freeze, so I’m not too worried about malicious websites, but others beware.
K. P. Harrier etro (9-14): First, welcome to the forum. Your post initially baffled me, as the tunnel’s location was unknown. The best I could determine, the tunnel is somewhere between Williams and Ash Fork (AZ). The double-track line between those points had the appearance of paired track, and each main took a different route. With the line relocation of this thread (1959-1960), both mains between Williams and Ash Fork were not need. The main that Santa Fe abandoned was the tunnel route you mentioned. The surviving main continues today and goes southwardly from Ask Fork to Phoenix. Have I, etro, surmised correctly so far?
Your post initially baffled me, as the tunnel’s location was unknown. The best I could determine, the tunnel is somewhere between Williams and Ash Fork (AZ). The double-track line between those points had the appearance of paired track, and each main took a different route. With the line relocation of this thread (1959-1960), both mains between Williams and Ash Fork were not need. The main that Santa Fe abandoned was the tunnel route you mentioned. The surviving main continues today and goes southwardly from Ask Fork to Phoenix.
That's my understanding yes. Although admittedly I'm not versed in this, just saw the post and thought you guys might appreciate the pics.
Should I have found this thread and the level of detail being discussed prior to my trip, I would have documented the visit much more thoroughly!
I can post coordinates if anyone is interested (and if that's appropriate?) where I picked up the line and the location of the tunnel. Or even send the GPS tracks. Let me know!
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