Mile markers & defect detection

Not quite sure on a couple of things, would anyone be able to explain the following for a moron like me?

With regards to mile post markers, are they placed exactly every mile? or are they put randomly? Is there a rule or set of rules regarding their location?
Also where would dragging defect detectors be placed? Is there a maximum speed that trains must pass over them?

Mile markers are not exact, at one time they may have. What you have to consider is that much of the existing roadbed has been realigned for whatever reasons. Realignments will cause the distances to be off. Some RR's have renamed "mile post" to "control points" that reference the numerical value of the mile post; MP 34.2 = CP 34.2.

Sometimes a mile marker will have a reference on where the start point location is, NY 29.1, the reference would be above the numbers.

John

Some US railroads place Hot Bearings detectors every 20 miles apart; while others use 30 or 40 miles spacing. It also depends on traffic density too. Lightly used lines may not have any form of wayside detectors. There are lots of variables as to how they are placed.

Dragging equipment detectors are like rules; they show up after somebody screws up. Draggers may be used prior to tunnels or major bridges or to protect a section of track that has had a rash of derailments.

When possible, trains try to avoid stopping over a detector as it may cause malfunctions or integrity failures.

Hi Eso,

In regards to the defect detectors, I've heard trains trip/roll over them as fast as 80mph for passenger trains and 70mph for freights.

Jordan

eso said:

Not quite sure on a couple of things, would anyone be able to explain the following for a moron like me?

Click to expand...

Keep in mind the practices on your railroads there in New Zealand may not match the practices in the US.

With regards to mile post markers, are they placed exactly every mile? or are they put randomly? Is there a rule or set of rules regarding their location?

Click to expand...

In the US, back in the days of telegraph / signaling poles along rights of way on most rail lines, mile posts were more common, but the mileage markers were less precisely placed. Although the railroad tried to place 40 poles to the mile, there were places where circumstances dictated that there be 38 or 42. The practice on that (and I would expect) on most US roads was that the pole nearest to an actual mile would be named that mile, so a pole located 35 feet from the actual mile locaton 321 might bear that mile marker. But then, in many instances, miles were too large a unit of distance, and the Rock Island marked the tenth (with a vertical sign containing one horizontal band), twentieth (horizontal bands), and thirtieth, (three horizontal bands) poles. Other track structures, such as highway grade crossings, bridges, and switches were also measured, and given more precise measurements, so that the highway crossing might be at milepost 347.32. For operating purposes, locations were given to the nearest tenth pole. If trackwork were being prepared for, or there were a slow order account bad track or other conditions, it would be delimited by tenth poles, so from 335 pole 20 to 339 pole 10. There was one exception to this. At various points around the railroad there were "measured" miles, which were marked by signs at the exact mile point. The purpose of these was to permit calibration of train speeds. The employees in those days were required to carry an accurate watch, and were required to be able to calculate the speed of the train by the number of seconds it took for the train to travel exactly one mile.

On many stretches of railroad in the US today, the lineside poles have been removed. But there is still a need for rail crews to know their location, so mile markers continue to be placed. These days they are on a shorter post, often a steel post like a fence post, and placed more accurately, so that the distance between two posts is more accurate than it was back in the days of lineside poles.

ns

Thanks guys, Exactly what I needed to know.

One last stupid question, where do the mile markers start from? Nearest yard? City? or something else like a fixed datum?

eso said:

Thanks guys, Exactly what I needed to know.

One last stupid question, where do the mile markers start from? Nearest yard? City? or something else like a fixed datum?

Click to expand...

They start at the beginning of the line. In the UK that would normally be from the company's principle station on a mainline, or the junction with the mainline for a branch.

Just for an example in regard to mileage and how it's measured. Up here CP rail has 2 main subdivisions in southern ontario, the Galt sub and the Windsor sub. The mileage of the galt sub starts from 0.00 at Toronto and increases to the west until London Ont mile point 114.6, and The Windsor sub starts 0.00 at London and increases to the west, until 24th street in Detroit which is mile point 115.00.

hope this helps some,
Jordan

eso said:

Where do the mile markers start from? Nearest yard? City? or something else like a fixed datum?

Click to expand...

In US practice, it was customary to begin counting mile markers at the beginning of the line, but there could be several "beginnings of the line" on a particular railroad, and sometimes the beginning of the line no loner started at zero. Further, "beginning of the line" usually was defined as where the line in question had it's earliest, or main connection with another bit of the same railroad. So, on the Rock Island, the Line from Chicago to Colorado Springs started numbering miles at La Salle Street Station in Chicago, and numbered miles all the way to Colorado Springs, from "0" at he bumpers to whatever the distance was to Colorado Springs. [When the Rock Island built into Colorado Territory, the state capital had not yet been chosen. CRI&P decided it was more likely to be Colorado Springs. They guessed wrong. After the state capital was established at Denver, the CRI&P negotiated entry into Denver over trackage rights.]. The line from Bureau Junction in Illinois, to Peoria IL, was a separate subdivision, and mileage started with 0 at Bureau Junction, and counted upwards to the end of the line in Peoria. The Rock Island had at least two other "Zero" milemarkers, one in Memphis, for the line between Memphis and Tucumcari NM, and one in Minneapolis, for the line from Minneapolis to Ft. Worth. There was one branch, though, where the mile markers started at5 3.7, This was caused when a relocation of the main line to which it connected meant that the new junction was at MP 3.7, and the milemarkers were not changed. There were also, in later years, branches which started at much higher mile markers, because the connection of the branch had been severed in favor of accessing remaining industires over trackage rights, so that there branches of a ten or twenty miles long where the milemarkers started at 47. When it was necessary to refigure mile markers, the railroad did not refigure any more than necessary. The realignment I mentioned earlier where the new junction on the branch was at MP 3.7, resulted in the subdivision including that branch being shortened by a few miles. Mileages were redone on the bit that was shortened, but starting at the next subdivision, the numbers were not changed, so that a Westbound train reached the subdivision point at milepost 357.3, and the next subdivision started at MP 361.

ns

History playued

In addition to mile markers, depending on the railroad, signals would be numbered according to their mile location.

So what do I do if the Defect Detector mentions a problem on a train? Does that even happen or is the DD just for show?

The fact that this thread has seen no posts (apart from this and the previous reply) for over 3 years suggests that nothing much has happened in this area. There are several defect detectors available on the DLS and, depending on your Trainz version, one is built-in. But there appears to be no "Defect Detector Rule" that would be necessary to produce a response, such as halting the train.

I just had a detector go off on my train. I programmed it so the Hotbox Sensitivity would be on High mode. I tested it by placing my train (a consist of one SD70 and about 14 tank cars) on the Southside of the crossing, while the detector was on the Northside. I saved the route, exited Surveyor and then went into the Session. When it began, I throttled up to Run 8. I got up to about 32mph in a 40mph limit zone when I was told by the detector (after the last car crossed over) that there was an Alarm. Then the mechanical voice said which axels were hot and it said "North Track" for some axels and then "South Track" for some other axels. I laughed. It was pretty good. But then I was like "Now what do I do?" I guess I'd have to just sit and wait until the axels cool of perhaps? I'm a "newbie" to this Trainz stuff.

I suspect that making the warning noises is all that these detectors do. The creator of the detector may not have built into it the ability to talk to other assets, such as a session rule, so that something can then be done about the warning. If this is the case then ignoring the warning will not cause any problems and it is all "just for show".

pware said:

I suspect that making the warning noises is all that these detectors do. The creator of the detector may not have built into it the ability to talk to other assets, such as a session rule, so that something can then be done about the warning. If this is the case then ignoring the warning will not cause any problems and it is all "just for show".

Click to expand...

Ok. Got it. Thanks.

jfriedrich said:

Just for an example in regard to mileage and how it's measured. Up here CP rail has 2 main subdivisions in southern ontario, the Galt sub and the Windsor sub. The mileage of the galt sub starts from 0.00 at Toronto and increases to the west until London Ont mile point 114.6, and The Windsor sub starts 0.00 at London and increases to the west, until 24th street in Detroit which is mile point 115.00.

hope this helps some,
Jordan

Click to expand...

Two questions: What about yards that are in towns? I set Yards in 3 towns. Do I have it start at 0 at Town A to Milepost 40 (Town B) and then start at 0 again at Town B to Town C which is roughly 41 miles away? Or are the starts and ends of the Mileposts to be done from city to city where the major terminals are? Also, I noticed Milemarkers on my Trackside Objects. When I place them down, do I manually program the number in or is it automatic when I place them down? How does that work exactly? Thanks.