RRD Mileposts (Was: 065)

[bth8446]

I almost bumped into it. But its far enough to the side not to be a danger.

Last year, they put in a concrete pad at the end of Hatboro station where I think they are going to put one of the new payement kisosk-y devices to tag-in/tag-out . . .
SO, what I was dodging was a sign placed right next to that concrete pad. the sign was attached to a newly sunk signpost. Its about 6 foot tall. And all it is, is a vertical
0
6
5
The numbers were slid into a slot meant for this applicaiton. the numbers are highly reflective displays. It was reminiscent of a mileage marker. The other one year old concrete pads
did not have any numerical designation, at the station. Just this one satellite concrete pad.

SO on my train ride I kept my eyes open, looking out for similar markings

Indeed it turned out to be mileage markers every 1/2 mile or so.
That point at the hatboro station is the 6.5 mile mark from . . . Glenside.
Just at the switches at glenside is a '000' triple zero marker.
This is all brand new, up and down the warminster line.

I continued to keep my eye out. The mileage markers are still in place (and aging) along the main rail

This is small time stuff, but it certainly raised my curiosity as to why they would put forth effort on such small time stuff.

Seeing the new signs made something clear. On most of the large beam structures holding up the catenary wiring are numbers. I now see that for the most part that numbers spray painted or posted with metal plates saying things like 29/6 pretty much represent the 29th structure in the 6th mile of this rail. I had noticed these numbers but didn't associated it with mileage. Only the mile markers made me aware of this, as I saw transitions as I passed the 5 mile mark and saw the postings on those metal beams switch to 23/4, and the next, 22/4, and the next 21/4 . . . you get the idea.

Some of you railroad pro's might know this like the back of your hand, but to me, a railroad greenie, its something I didn't know (and still may have a few misconceptions about).

Any idea what brougth on this action (new postings of the mileage along Warminster, and perhaps other lines)? Some railroad rule? Audit finding? . . .

[ExCon90]

I don't know either, but the mile markers are on the Media/Elwyn line now too.

[MACTRAXX]

BTH: On a recent visit I took notice to these new SEPTA RRD Mile Post Markers...

These mile markers look to be placed every 1/2 mile...

Mile markers on these routes date from Conrail days in the mid-late 1970s previously...

Yes-SEPTA Catenary poles are marked on a mile basis: 22/11 would mean the 22nd pole in the 11th mile...

[aem7]

The new mileposts signs you see are in whole mile and half mile increments and are part of the PTC wayside installation program. Train Dispatchers will be using whole mileposts as well as the half mile markers to input speed restrictions or work zones into the PTC computers. Start date is 12/31/15.

065 means milepost 6.5. Hope this helps.

[RDGAndrew]

Noticed SEPTA has put up reflective markers next to both tracks on the West Trenton line at Rydal Rd, with 1-2-5 in black vertically on a white background. Clearly 12.5 miles from Center City, but I'm wondering if it's a milepost or just a crossing identifier? Seems a milepost would just be at the full mile, not the 0.5, with the in-between distances marked on the cat poles. I cross the Warminster line en route to work and haven't seen them there yet.

[ExCon90]

See aem7's post of July 11. The markers have been showing up on the Elwyn line at 1/2-mile intervals. One question that occurs to me is that when a dispatcher wishes to enter a slow order into the system, will he be bound by the 1/2-mile markers, or will he be able to input something like "between 124 and 128," with the wayside markers just for reference, or would that have to be 120 and 130? If the latter, it would be just one more example of signaling "improvements" slowing things down.
(On the UP I have seen quarter-mile posts, but I can't remember just where; i.e., former UP trackage, or WP, or SP.)

[SCB2525]

In this case, the "improvements" are federally mandated.

[Limited-Clear]

You are incorrect about it slowing things down, it will actually speed things up, speed restrictions must use places that are identifiable, such as bridges with milepost location, stations or whole mile markers, now the half mile posts are going in restrictions will be more precise and you won't have such big restriction areas

[aem7]

Temporary speed restrictions (TSRs) will be sent to the train using the half mile posts at each end of the restriction. Road crossing that are out of service will use the road crossing's specific mile marker and will bring the train to a mandatory stop some 50 feet prior to the crossing. In layman's terms, it's a combination of GPS locations, digital radio signals and transponders located in the gauge of the rail.

[ExCon90]

You are incorrect about it slowing things down, it will actually speed things up, speed restrictions must use places that are identifiable, such as bridges with milepost location, stations or whole mile markers, now the half mile posts are going in restrictions will be more precise and you won't have such big restriction areas

I have seen slow orders stating simply umpteen feet east of milepost soandso, with no landmark mentioned.
Actually, what I was thinking of are the slow orders now in effect on the Cobbs Creek and Darby Creek viaducts. The present S and R boards are at either end of the viaducts; apparently that won't be possible under the new system. Will the S board now have to be at the preceding 1/2-mile point and the speed board a corresponding distance in the rear of that, with no resumption of speed after crossing the viaduct until the next 1/2-mile point?

[aem7]

I believe the S and R signs you are referring to are for possible flooding conditions. ( Special Instruction FS-1.) They have nothing to do with PTC.

[Limited-Clear]

He is referring to a speed restrictions in place over 2 bridges on the Elwyn line, and yes it would more than likely make that speed restriction between MPs with PTC, unless the bridge is listed in the system with its length, then the train will know by location where it is, the half MPs will probably be used more for immediate restriction that are found in track inspections, I'm sure we will find out soon, too much speculation right now

[jb9152]

You are incorrect about it slowing things down, it will actually speed things up, speed restrictions must use places that are identifiable, such as bridges with milepost location, stations or whole mile markers, now the half mile posts are going in restrictions will be more precise and you won't have such big restriction areas

Not going to help much, as PTC by nature will slow things down. Will get into the details, if desired, but it's a bit off-topic.

[Limited-Clear]

PTC enforces speed limits, it also stops engineers from getting too close to stop signals, the system unless butchered won't slow things down, now CSS on the other hand does slow things down with cab signals dropping to more restrictive signals further away, remember PTC is an overlay to CSS, running normally and PTC will pretty much stay quiet, Amtrak trains that are running in PTC territory aren't seeing massive slow downs, they still run ontime

[jb9152]

PTC enforces speed limits, it also stops engineers from getting too close to stop signals, the system unless butchered won't slow things down, now CSS on the other hand does slow things down with cab signals dropping to more restrictive signals further away, remember PTC is an overlay to CSS, running normally and PTC will pretty much stay quiet, Amtrak trains that are running in PTC territory aren't seeing massive slow downs, they still run ontime

In actuality, PTC speed enforcement will cause slow-downs versus wayside or CSS train control.

It's easier to see if there's a visual, but think of it this way - currently, an engineer knows a speed restriction is coming up because he/she knows the physical characteristics and has the bulletin(s) that show temporary slow zones. Or there may be a speed sign on the wayside in some places. When an engineer is familiar with the run, has a feel for the equipment, and has some experience, he/she will make a judgment about where to make the first reduction in order to be down to the required speed in time. With PTC, the system must, because of all the unknowns, assume that (exaggerating a little to make a point here) the brakes are not working very well, the rails are coated with Vaseline, and the engineer has no idea what he or she is doing. So, the enforcement point, at which the brakes will be applied automatically, will be moved further back, to compensate for all of the things that PTC cannot know with any accuracy. Then, there is a warning time requirement, so that before the engineer runs smack into the penalty brake application, there is an audible and/or visual warning, much like CSS. That's offset from the enforcement point by some reasonable distance, to give the engineer fair warning before hitting the penalty. Once that warning goes off 5, maybe 10 times over a week or two, the engineer, without necessarily being conscious of it, will begin to apply brakes just before the warning sounds. He or she may use a visual cue without even knowing it, like a certain tree, or a McDonald's or whatever, to apply the brake so as not to hear the annoying alerter. That will set the braking point back yet further. That's known as "engineer pre-action", and it's something that the LIRR has known about for a long time.

CSS is used in a very limited way to enforce civil speed restrictions. Because of the limitations of the speed codes, it's not the most efficient way to do it - you have a limited menu of speeds from which to choose. So, a 55 mph speed restriction has to become a 45 mph restriction because that's the closest lower speed. PTC will enforce to the actual mph, but because of all the safety margin included, the warning point, and the pre-action phenomenon, the effect will be to push the initial reducing brake application significantly further back than would happen without PTC.

Hope that was clear. Like I said, it's actually easier to draw.

Didn't mean to take this off topic! If the mods want, feel free to delete my post.