Not Rocket Science … Saving Fuel on a Famous Hill
About the Ash Hill area on the western part of southern Transcon, way out in the relatively secluded desert of Southern California:
Westbounds often zip through the desert at 55-70 M.P.H. Then, they come to an area called Siberia. There is a much slower speed curve, and a hill to lug up (“lug up”) to Klondike and Ash Hill.
https://www.google.com/maps/@34.6386034,-116.0063632,1580m/data=!3m1!1e3
Why doesn’t BNSF just redo the curve, make it a swooping 70 M.P.H. affair and use the speeding forward motion of trains to move them up the hill?
----------------------------------------------------------------------------------------------------------------------------------- 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.
What would be the grade on a direct route from Sibera to Klondike?
Railroads climb grades by extending the mileage between the low and high points so that the entire route will have an acceptable grade (nominally 2% or less). Curves are a tool in extending the mileage between points - Horseshoe curve on PRR/NS and Big Ten Curve on DRGW/UP were designed for the purpose of climbing the grade.
Never too old to have a happy childhood!
The 1.4% westward climb starts several miles east of the 6-deg curve. How many freights do you think approach the curve at more than 35 mph?
The fast ones can use the other track if they're that eager.
Given the length of the combined stacker-trailer train in the Google map snap shot, it looks like the front end might be going through the second curve while the rear of the train is still going through the first curve. (Looks like 4 Gevos up front pulling 97 wells with double stack containers and 8 wells with UPS 28 foot trailers loaded.)
Also, someone on the Santa Fe (Or is this on the part that was originally constructed by SP to meet up with the A&P coming west?) - maybe the original construction foreman - obviously had a wry sense of humor naming two points in the middle of the parched, torridly hot desert "Klondike" and "Siberia".
A train at 70 MPH has a 'velocity head' (kinetic energy, proportional to the square of the velocity) of about 164 vertical ft. for the train alone (what follows might help understand this), and not including the minimal additional energy in the wheels.
A 1.4% grade rises about 70 ft. per mile.
164 ft. / 70 ft. = 2.3 miles until the train comes to a stop from having used up all of its rolling energy, assuming that the locomotives don't add any in that distance. But of course they will, so the train will go on, but not as fast up that grade without a huge HP / ton ratio - like 5 to 6 HP / ton, which usually isn't seen anyplace except fast passenger rail operations.
In comparison, a 35 MPH train has about 41 vertical ft. of velocity head. 164 ft. starrting up - 41 ft. at 35 MPH = 123 ft. difference, so a 70 MPH train would have slowed to 35 MPH after about 123 / 70 = 1.8 miles on that 1.4% grade. Such a train would need about 2.6 HP / ton, a much more reasonable, achieveable, and typical amount.
- Paul North.
EDIT: I forgot to divide the velocity head numbers by 2 (VH = V^2 / 2 x G). Corrected numbers above accordingly 6:20 AM EDST 06 May. Also made some edits in last paragraph. - PDN.
Paul D. North Jr. (5-5):
Hi, Paul!
I speak Hebrew and NOT Greek. Serious, I perceive you were saying something significant, but I lost the import in not understanding the language of what you were saying.
The top track below is that 35 M.P.H. curve.
Over the years I’ve consistently observed westbound trains reducing the run numbers and sort of partially coasting the last miles until that curve. It would seem an engineer would need skill in not pulling too hard after rounding that curve in order not to pull his cars off. On the other hand if trains could be kept moving at a higher speed (with a swooping curve), in theory it would be more fuel efficient. Is that what you were trying to say, or the opposite? Maybe something else …
Take care,
K.P.
Looking at the Google map photo. it looks as if the two curves at each end of the "zig-zag" have been significantly eased at some time in the past. I guess this process could be repeated.
M636C
K.P. - What I'm trying to demonstrate is that a 70 MPH train encountering a 1.4% grade is going to be down to 35 MPH anyway after 2 to say 5 miles, unless it has a massive amount of power.
That 35 MPH curve may be in the middle of that 'slowing down zone', so the engineer just accepts that's going to happen a mile or two earlier than the grade alone would make it happen. The time difference would amount to only a minute or two - 2 to 3 miles at 35 MPH instead of about 50 (average of 70 slowing to 35).
It doesn't matter much anyway, because the energy/ fuel to go up the hill is roughly the same regardless of the speed - just weight x height. Also, the time to do so is about the same for a given HP / ton ratio: higher speed over a lower grade & longer distance vs. lower speed up a steeper grade & shorter distance.* Actually, the higher speed would be slightly less fuel-efficient due to wind resistance, etc.
*See: "Shorter plus steeper equals faster plus cheaper - accent is now on speed, not tonnage", by LeMassena, Robert A., from Trains, August 1970, pgs. 44 - 46.
Louis Kingman, Chas. Holbrook and the other contributing parts of the "Big Six" knew what they were doing. Until there is economic justification, everything will stay as is.(and you haven't experienced a desert flash flood / cloudburst out there either, the lower line has been threatened multiple times)...
(there have been plenty of capital budget proposals and preliminary surveys/ engineering done out there - resulting in broken dreams posted to the back of a drawer somewhere....Just can't justify the expense.)
DC will jump in here somewhere. (You need a serious scorecard to track the gyrations of A&P/ATSF and SP out there on that part of the transcon.) To this day, the roadmaster at Needles keeps a wary eye on that country.
Between Ash Hill and Siberia SP built the original shorter line with 2.00 % westward grade. Santa Fe built the longer line with 1.44 % westward grade when the double track was created. We must keep in mind that doubletracking between Barstow and Belen was done in segments with these constraints and priorities: money available; needs to reduce grades, and local conditions such as flash flooding as MC has mentioned.
The most dramatic proposal studied was in the early 1960's when a proposal for a new double track design between Goffs and Ash Hill, like Williams-Crookton, was considered using atomic explosions to create massive cuts which accomodate both the railroad and I-40. The Federal Government and the State of California were participants in this study as well as the Santa Fe Engineering Dept. Santa Fe's lead man was Roy Stane who had been in charge at Williams. For reasons we can now understand this never progressed beyond analysis; but it did involve our prime Atomic explosion experts who also conducted the explosions in the isolated Pacific islands.
Interesting read on "Project Carryall"
http://atomic-skies.blogspot.com/2014/02/project-carryall.html
I speak from experience when I say that it doesn't take very long at all for a 1.1% grade to overcome the momentum of a ~25 mph, four car train being pulled by an 1800 HP locomotive.
In the fall (wet rails and leaves), that transition point announces itself loud and clear by means of the wheel slip indicator. Giving it a half mile would be charitable.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
diningcarBetween Ash Hill and Siberia SP built the original shorter line with 2.00 % westward grade. Santa Fe built the longer line with 1.44 % westward grade when the double track was created.
Likewise west of Ibis-- the steeper track is the newer one. Likewise west of Ash Fork-- the steeper track west of the flyover was the newer one.
A westward train climbing to Ash Hill needs 4 hp/ton (or more?) to make 35 mph on 1.4%, and the limit on the former-westward track is nowhere lower than 35. How many trains do they run with 8 hp/ton?
tree68I speak from experience when I say that it doesn't take very long at all for a 1.1% grade to overcome the momentum of a ~25 mph, four car train being pulled by an 1800 HP locomotive. In the fall (wet rails and leaves), that transition point announces itself loud and clear by means of the wheel slip indicator. Giving it a half mile would be charitable.
25 MPH = 36.8 ft./ sec.; energy = 36.8 x 36.8 / 2 x 32.2 = 21 ft. of velocity head.
21 ft. / 1.1% (1.1 ft. per 100') = 1,910' = 0.36 mile. Maybe increase that figure a little bit for what the loco is able to add during that time, and Larry/ tree68's observation/ estimate checks out for consistency pretty well (of course !).
Somewhat tangentially related to rocket science, Neil Armstrong was known for occasionally starting speeches with a faux joke about being on the moon that ended with a deliberately unfunny punch line. After the audience would not laugh, he would shrug his shoulders and say "Oh well, I guess you had to be there."
timz, you write with confidence which I attribute to personal knowledge about the track configurations between iberia and Klondike. I on the other hand did not write with specific personal knowledge. My analysis was based on engineering logic and is why I assumed that the original (SP) alinement took the shorter but steeper grade along the desert wash which may have later proven to have a significant wash out problem. Then as the second track 'segment' of the later to be westward track was constructed the engineers chose to lighten the grade and move away from the wash out problems.
We must remember that the left-right-left westward running was not implemented until there was a significant amount of 2nd track available and thus the lighter grade would have aided the heavy westward freights until then. Anyway, that was my thinking and I again assume you have more specific info so thanks.
Don't have any personal knowledge-- just impersonal. Don't recall if the Railway Age article on SFe doubletracking in 1923 mentioned the cutoff east from Ash Hill-- probably did. In any case, looking at the charts you see how the mileposts are fairly continuous along the longer track, while the cutoff has the X-mileposts and a milepost gap.
The USGS guidebook to the SFe (with the foldout maps)
https://pubs.usgs.gov/bul/0613/report.pdf
shows (pdf page 226) the single track on the 1.4% line Siberia to Ash Hill. The cutoff west of Ash Fork was older, so it's on the guidebook map-- but it had X-mileposts too.
The cutoff west of Ibis dates from around 1950-- you remember in 1948 California voted out its full-crew law, which had required more brakemen on steeper downgrades. Once the law was gone the Ibis cutoff could be built without needing an extra brakeman.
(You might wonder: what about the extra brakeman east from Ash Hill? Mr Kauke said before 1948 some eastward SFe freights did carry the extra brakeman, dropping him at Bagdad to deadhead back to Barstow.)
Paul D. North Jr. (5-6):
Nicely put, Paul, and much easier to understand for this rather laymen on such matters.
It would seem, however, if big swooping curves were utilized in the Siberia area, a westbound train traveling at 65 M.P.H., instead of coasting uphill to that 35 M.P.H. curve and Run 8 thereafter, if it instead was in Run 8 all the way and on swooping curves would make much, much better time and use less fuel in the long run, unless those that believe the operating philosophy of long, heavy, and lugged trains are right.
How does that mesh with your thoughts, Paul?
Thanks,
K. P. Harrier Paul D. North Jr. (5-6): Nicely put, Paul, and much easier to understand for this rather laymen on such matters. It would seem, however, if big swooping curves were utilized in the Siberia area, a westbound train traveling at 65 M.P.H., instead of coasting uphill to that 35 M.P.H. curve and Run 8 thereafter, if it instead was in Run 8 all the way and on swooping curves would make much, much better time and use less fuel in the long run, unless those that believe the operating philosophy of long, heavy, and lugged trains are right. How does that mesh with your thoughts, Paul? Thanks, K.P.
My reading of Paul's comments is that even in Notch 8, the train will be down to 35 mph by the time the train reaches the first of the curves, simply due to the energy expended by climbing the grade.
There is no question of "coasting up grade" to drop down to 35 mph. The grade does the slowing against full throttle.
But that is just my interpretation.
timz, I got the tracks west from Ash Fork up on Google Maps and I conclude that the 2nd track construction crossed over the original A&P alinement and made the much longer and horse shoe curving alinement through the Station of Gleed.
KP has shown photos of the bridge abutments where they crossed and the new alinement is the one on top of the bridge, hence was the 2nd track. This makes perfect sense as there was now partial left hand running and this placed the westward trains on the new and much lesser grade; and in the process crossing from being the south track to being the north track as they went west.
Take another look at the map west of Ash Fork. The new track flew over the old track all right, but the old track was the one that took the longer 1.4% route.
K. P. Harriera westbound train traveling at 65 M.P.H., instead of coasting uphill to that 35 M.P.H. curve and Run 8 thereafter, if it instead was in Run 8 all the way and on swooping curves would make much, much better time
Why do you assume today's westward trains coast up to the 35 mph curve on the north track? If they only have 4 hp/ton they can't exceed 35 mph anyway. Do lots of trains have more than that?
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