Why would mileposts not be spaced 5280 feet apart (or close)?
I can understand why if there was a reallignment, but in looking at a track chart a sampling of distances between the markers for a five mile section runs as follows: 5740’, 5294’, 4820’, 5248’ and 5320’. Those five miles average to 5284’ which is close, but it seems just a bit odd.
ed
Mileposts are often in the wrong place due to line changes that introduce cumulative errors, or the post is just in the wrong place. There are many, many short and long miles, and track charts are often badly out of date now because the large workforce required to keep them up to date is long gone. The mile marker is what counts and it is a survey location. It may or may not be anywhere near the milepost. Mud can no doubt add more, I’m an amateur when it comes to survey. Suffice it to say that nothing is engineered until a survey is conducted, and getting the survey to work without busts in engineering stations and mile markers can be a painful challenge.
RWM
Welcome to the real world. (To quote Robin Williams - “Reality, What a concept!”)
Those surveyors of the 1800’s and early 1900’s had no GPS, no calculators, no EDM’s, no CADD.
Low precision transits, tables, log rules, wye levels and chains were as good as it got.
MP173 lives in a public lands survey system (PLSS) state. Would he care to guess how many sections are exactly a mile square (640 Acres)?
In addition to math and rounding errors, you have the differences between horizontal and at-grade measurements, pro-ration, the operating department, lawyers, curve changes (simple to spiral), floods and washouts…and so on…
Lord, mud, it couldn’t be any worse than Imperial County in California. You can look at the section lines there and see offsets of close to 20 rods or so at the corners. The government survey was done sometime before the turn of the century, certainly before the area began to be settled, and the local legend is that the surveyors spent a little time down there in the summer, then retreated to the mountains and “completed” the survey under some shade trees up there.
(The SP at one time owned a lot of farmland in Imperial Valley and at the outset of habitation was an active promoter of settlement of the area and, of course, was instrumental in repairing the breech in the Colorado River banks which caused the two-year flood that turned Salton Sink into the Salton Sea.)
Of course, there were some other surveys in California that were repeated later with much better instruments and found to be astonishingly accurate. Like everything else, there are people who do good work and there are others not so skilled or motivated.
…But M C…There was lots of engineering accuracy accomplished and required back a century plus ago to successfully construct many of the tunnels and many other infrastructures. Why then, doesn’t the “mile Marker” live up to what was required in the above…?
Hmm, no wonder a couple of those “miles” on my bike route seem to be slow miles or fast miles, those county roads (sections) are a little off!
Thanks for the updates.
ed
i was told by the track men That the T&S Gangs haft to compleate 3 miles of track a day and sometimes they just cant get it done but haft to show for it. so they go and get the milepost and bring it back to where they finish and stick it in the ground. ive seen this done 1 time
Because it didn’t have to. Advancing two tunnel headings to meet is critical. If the mile poles are 5280 or 5112 or whatever feet apart, it’s not very important.
RWM
Reminds me of a story.
Once a Roadmaster gave a Section Foreman orders to build a tool house exactly half way between two mile posts. The Foreman had chose one of his gang members and told him, “You go to the east mile post and I’ll go to the west one. We’ll both start walking toward each other at the same time, and where we meet will be the middle and we’ll build the tool house there.” So they did that and built the tool house.
A neighboring Section Foreman heard about this. The next time he ran into him he said, “You know that tool house you built isn’t half way between the mile posts. The person you chose had long legs and a big stride while you are a short fellow with a small stride. You’re going to have move the tool house.”
A few days go by and the Roadmaster is touring his territory. When he comes across the Foreman he told to build the tool house, he says, “I heard the tool house you built wasn’t exactly in the middle. Did you have much trouble in moving it to the half way point?” “Oh no,” said the Foreman, “No trouble at all. I moved the mile post instead.”
Jeff
More often, the Jordan Spreader or the ballst regulator knocks over the milepost in the field. Joe Tracksupervisor / Motor track inspector hops in his trusty hi-rail and uses the odometer to put the thing back. Problem is the truck now has 19 inch hirail wheel rims instead of the 16 inch rims it came with (Odometer long mile problem)…
Most foremen don’t move the mileposts, they just keep footage from a more productive day “in their pocket” for just such an emergency.[;)]
Jeff – that reminds me of a story from the late, great, Ernest King, who rose from messenger boy to VP-Western Region on SP. At the time this story occurred he was the superintendent on the Sparks Division. The division roadmaster was notorious for supplmenting his material needs with whatever might be laying around on another division. The roadmaster in question was short of a particular style of tie plate, noticed them at a stockyard just to the west of his territory, and one night appropriated them, having slyly boasted to Mr. King in advance that he had a method of meeting his needs. King guessed what he was going to do that night, and the next morning by agreement with his adjoining superintendent shifted the boundary between divisions just far enough west to encompass the stockpile, so that the roadmaster had worked all night to steal his own tieplates!
RWM
That reminds me of the consulting engineer who suddenly found himself at the pearly gates. He walked up to St. Peter with confusion on his face, and said “St. Peter, I am only 37. I did not think my time was due.” St. Peter replied, “According to my records, your billable hours to date would make you 103.”
RWM
Thanks to the masked man with the cape and the big “R” on his chest! [:D] I would have dragged out the standard question about knowing the difference between accuracy and precision and gone from there. (macro vs micro, etc.) [D)]
[banghead][banghead][banghead]
There are all sorts of anomalies in mileposts. Near the Weber Road crossing of the BNSF here in South County, there is a signal post which has two mileposts attached.
One says 10.4 and on the other side is 10.5. This would tend to make the signal post a tenth of a mile wide to be accurate.
Welcome to the “wunnerful” world of station equations.
(still remember a union greivance about there not always being exactly 30-35-40 poles per mile in a given crew district [(-D][(-D][(-D])… now there aren’t any.
That’s different! Numberplates on signals are only references to milepole locations, not milepoles. All non-absolute signals bear numbers. The numbers usually refer to the nearest 10th of a milepole so everyone has a general idea where that signal is located. The numbers must be different if there are more than two signals at the same location so the signal department and operating department can tell the two signals apart on both the circuit diagrams and for train operation. For example, on a typical western railroad, the two ABS signals at milepole 685.8 on an east-west railroad will number the eastward signal 6858 and the westward signal 6859. If there are four signals at that location for two main tracks, the eastward signal would be numbered 6858-1, 6858-2 and the westwards 6859-1 and 6859-2. The -1s go on Main Track #1, the -2s on Main Track #2.
Some western railroads only numbered to the nearest mile, not the tenth, so the intermediates between milepoles 101 and 102, for example, would be 1011 and 1012 even if they were actually at milepole 101.8. Some western railroads like to put a decimal point into the number, others do not.
Where there are signals in close proximity to each other and you “run out of numbers” the numbers will be adjusted to fit. For example, if you have signals at milepole 102.8 and another set at 102.9, they would be numbered 1026-1027 and 1028-1029, in order to indicate they’re all to the low-number side of milepole 103.
RWM
Sometimes the railroads put their mileposts only on the telegraph poles. If a pole got destroyed (fire, lightning, wreck) the mile marker got a temporary move to the next pole. When the new pole was set it couldn’t be exactly where the old one was located because of the original buried stub. Sometimes someone forgot to move the mile marker back, etc. Stretch this out over 100+ years and you get the picture why the mile markers are not one mile apart in addition to the original errors MC mentioned.
On the SOO, milepost 145 at Hoffman, MN was in at least 3 different locations 1978-1996 due to various reasons. At Drake, ND MP 418 on the main track sits directly across the yard from MP 419 on the New Town line, due to several pieces of line relocations between Farwell and Nashua, MN nearly 100 years ago.
Thanks, Railway Man. That explains it clearly. I wasn’t exactly losing sleep, but it did seem somewhat strange.
Back when that line was the Frisco River Line, they controlled train movements with upper quadrant semaphores spaced about a mile apart. It was easy to tell if there was some activity in the block, but I always wondered if they were exactly a mile apart. Never got around to figuring out a way to measure, and before I knew it they were gone.
All of this discussion about mileposts brings up another question or two:
What happens in a merger such as the UP/SP where the original mileposts were from SP’s headquarters in San Francisco. Where does the UP measure their mile 0, and would they go to the expense of changing all of the mileposts on the former SP lines?
In one area here in SE Arizona the UP is planning on a track realignment that will eliminate over 10 miles of track distance on their Sunset Route east-bound line, but the west bound track will not change. Would the east and west bound tracks have different measurements because of the long loop that the east bound makes and the west bound doesn’t?
Actually, the placement of the mile post explains all the confusion. [bow][8D]