Mile Marker's

With a 3 or 4 track mainline are the mile markers placed on each track ? or just each outside track ?.

I have a track chart to follow so i know where to place them roughly but this is for the Powder River Basin which has a lot of it that is Bi-Directional ( I think that is the correct term ).
Thanks for any help.
Cheers Mick.

In NSW the practice was to place the distance markers on the UP (towards Sydney) side of the track - defined as on the drivers side (left hand drivers seat). That way track workers would also know which direction was UP. Where a cross country line was involved (e.g. Parkes to Cootamundra, or Demondrille to Blayney) the UP direction was defined as the end closest to Sydney. Where dual track was involved, only the UP side track had the markers.

On the multiple-tracked mainlines I know of, I've seen mile markers on the outside only. Then again where I live, our tracks are at 4.5 meter spacing and narrower since they're some of the earliest railroads built in the US, and many of these were built to British standards of the railroads built at the same time.

Regarding the Powder River Basin. I've traveled out in that part of the country to Gillette, Wyoming, and then up through Montana and the Black Hills of South Dakota. Once the tracks leave the basin area, where the coal is loaded, the tracks quickly narrow down to double then single track for the rest of the way with periodic passing sidings. Things might have changed in the past couple of years, but this is how I remembered seeing it from the parallel Interstate 90 freeway.

John

The old NYC 4 track mains (now 2 tracked, CSX's Rochester Sub) near my area still have mostly the old cement markers which as far as I know were only ever on one side of the tracks. Most other railroads around here that were double tracked at one time (specifically thinking about the old Erie line, now NS's Southern Tier Line) were single tracked in the middle of the last century so I can't really use that as an example.

I feel it should be noted that at the time older mile markers were put in, measurement techniques weren't quite what they are today with accurate odometers and GPS, and this, along with minor realignments over the years, doesn't always mean mile markers are exactly at the "miles" - sometimes off by as many as 100 feet, which is now usually denoted in the maintenance charts.
In some cases there are even large jumps in mileage because of a major realignment that messed with the numbering - rather than renumber the entire route, they'd continue the numbering along the new alignment from one end until it reached the other end and just make the numbers at that point be non-continuous.
Just something to think about if people are trying to use their "1 mile consists" and spending hours getting the mile posts exactly placed, but then wondering why if you're doing a proto route the miles don't match at some point.

When because of realignment the total distance was shorter, did they signal the discontinuity by some special sign or signal? Or was 51.2 followed by 51.4, and leave it up to the observer to know that the missing value was not just over looked.

In the possibly rare case where the distance became longer than it was originally, how was that signed?

Besides the regular mileposts every mile (these were necessary because locomotives didn't have speedometers back in the day - one of the crew would actually time themselves between mile markers to figure out their speed), yes there would typically be markers of some kind to indicate the discontinuity, but what it would be would probably vary from RR to RR. The discontinuities I'm referring to would be more along the lines of going from mile 324 to 332, much larger than 2/10 of a mile.

I'm not sure what they would do in the instance that it was lengthened, I haven't encountered any major ones that I'm aware of. In smaller instances, they may "stretch" the miles a bit longer (just as they may "compress" them in minor shortenings).

There are situations where a double track line takes different paths for the two tracks.

For example, a line may be required to traverse a steep climb in the UP direction and a correspondingly steep descent in the DOWN direction. While this would not necessarily be a problem for the DOWN track, the UP track may be required to take a longer diversion such as a spiral around the hill with the result that there is a difference in the mileage (or "kilometre-age") between the UP and DOWN tracks. There is one such example here in NSW at the Bethungra Spiral on the Main South Line where there is a spiral on only one of the two tracks (I believe the UP track) which has two tunnels as well as the spiral.

Thanks for the reply's and help fella's, Not really the answer's i was after but i'll keep working on it.
Cheers Mick.

As I said with the 4-track NYC main through upstate New York, I'm 99% certain the stone mile markers were only placed on one side of the line entirely. Are you trying to model current or historic? If you want to know what they do currently, find a milepost that would be near a grade crossing and drive there with a pair of binoculars to look. Or check Google Streetview. Though in all honesty I doubt anyone driving your route would complain that your mileposts are really on the wrong side.

PS: 's is used primarily for possessive (ownership), not every plural word (multiples). (also replies, not replys). Sorry, just being a grammar nazi again.

ctclark1 said:

As I said with the 4-track NYC main through upstate New York, I'm 99% certain the stone mile markers were only placed on one side of the line entirely. Are you trying to model current or historic? If you want to know what they do currently, find a milepost that would be near a grade crossing and drive there with a pair of binoculars to look. Or check Google Streetview. Though in all honesty I doubt anyone driving your route would complain that your mileposts are really on the wrong side.

PS: 's is used primarily for possessive (ownership), not every plural word (multiples). (also replies, not replys). Sorry, just being a grammar nazi again.

Click to expand...

Yeah thanks Ctclark1 i was going to stick with the one side only idea but being that it's the modern era i am going for i thought a mile post each side would be more prototypical.

Some signal panels are labeled with the plate below it, mile distance, ie: MP 237.8

The Horseshoe Curve had 4 tracks, but only one cast iron milepost simply marked: "242" (which has been replaced by a simple sheet metal sign, one cheap metal sign post on the outside, #4 track).