John Baker
Electrolove,
For more than you ever wanted to know about full scale track gauges, try:
http://turksib.com/gauges/index-e.html
click on link
Caution - LINK SITE HAS PROVEN TO BE A CHANGEABLE TO SALES - ADVERTISING SITE - ORIGINAL INFO NOT ACCESSIBLE if link clicked directly.
(Edited Monday, 14 Aug 06, 9:38AM)
Chuck (found at 762mm and 1067mm, but not at 1435mm)
4 feet 8.5 inches is standard gauge.In curves, sometimes it is widened slightly (1/2" to 1") to get to trains thru without derailing.If it is more than say 2" wider, that is called wide gauge. Usually found at derailment sites. The rails spread, and down you go.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
rtpoteet1 wrote:Keep one thing in mind, however; gauge is not measured from the inside of one rail to the inside of the other rail; it is measured from the inside of one rail to the OUTSIDE of the other rail. More accurately - but this gets a little hard to measure - its from the center of one rail to the center of the opposite rail. That's because of the thickness of the top of the rail whatever its called. PICKY! PICKY! PICKY!
I have to disagree. NMRA standards diagrams clearly show inside of rail head to inside of rail head as the measuring point. The NMRA gauge measures the same way. I would want convincing proof the prototype does not do the same. Rail head thickness is not standardized in either the model or the prototype; it usually varies with rail height. Therefore, measuring gauge anywhere except inside rail head to inside rail head would be inconsistent with a single spec, and difficult to keep consistent. I do remember reading that modern prototype practice does not allow the gauge to get more than 1/2" wide because of increased wear and other problems.
my thoughts, your choices
Fred W
fwright wrote: rtpoteet1 wrote:Keep one thing in mind, however; gauge is not measured from the inside of one rail to the inside of the other rail; it is measured from the inside of one rail to the OUTSIDE of the other rail. More accurately - but this gets a little hard to measure - its from the center of one rail to the center of the opposite rail. That's because of the thickness of the top of the rail whatever its called. PICKY! PICKY! PICKY! I have to disagree. NMRA standards diagrams clearly show inside of rail head to inside of rail head as the measuring point. The NMRA gauge measures the same way. I would want convincing proof the prototype does not do the same. Rail head thickness is not standardized in either the model or the prototype; it usually varies with rail height. Therefore, measuring gauge anywhere except inside rail head to inside rail head would be inconsistent with a single spec, and difficult to keep consistent. I do remember reading that modern prototype practice does not allow the gauge to get more than 1/2" wide because of increased wear and other problems. my thoughts, your choices Fred W
I agree. It has to be from inside to inside. The width of the rail doesn't really matter as long as it is at least "enough", and would change the center to center measurement. The spacing of the flanges on the wheels and the didtance from inside to inside of the rails are the critical measurements.
Jeff But it's a dry heat!
electrolove wrote:What's the distance between the rails in the real world? And in HO scale? I know I can just measure my HO scale track * 87.1 but I want to know the exact distance.
cwclark wrote:there's also a story behind the 4' 8 1/2"...back when the country was young there were railroads popping up all over the place...each railroad would custom build their own locomotives, rolling stock, and track gauge....you can see the problem this caused...say you wanted to ship goods from one part of the country to another which might mean that you may have to ship it on four or five different railroads because one railroads track gauge was different from another's and each other's equipment wouldn't fit on each others rails ...can you imagine the cost and the time it took for loading and unloading the goods from one railroad to another and another and so forth until your goods were moved to it's final destination?...so to streamline the operation, ol' Abe Lincoln inacted a bill that would standardize the nation's rail gauge...the standard would be 4' 8 1/2"...the width between the wheels of the old Roman chariots....chuck
This is worth a look:
http://www.snopes.com/history/american/gauge.htm
"Keep one thing in mind, however; gauge is not measured from the inside of one rail to the inside of the other rail; it is measured from the inside of one rail to the OUTSIDE of the other rail"
Where do people come up with this rubbish?
Cheers
Roger T.
Home of the late Great Eastern Railway see: - http://www.greateasternrailway.com
For more photos of the late GER see: - http://s94.photobucket.com/albums/l99/rogertra/Great_Eastern/
Howdy:
If I may add my 2 cents worth, here is what I found on the Web regarding the origin of the 4'-81/2" standard:
From: Professor Tom O'Hare, University of TexasSubject: Mil. Specs
How Mil Specs Live Forever
The US Standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That's an exceedingly odd number. Why was that gauge used? Because that's the way they built them in England, and the US railroads were built by English expatriates.
Why did the English people build them like that? Because the first rail lines were built by the same people who built the pre-railroad tramways, and that's the gauge they used.
Why did "they" use that gauge then? Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing.
Okay! Why did the wagons use that odd wheel spacing? Well, if they tried to use any other spacing the wagons would break on some of the old, long distance roads, because that's the spacing of the old wheel ruts.
So who built these old rutted roads? The first long distance roads in Europe were built by Imperial Rome for the benefit of their legions. The roads have been used ever since. And the ruts? The initial ruts, which everyone else had to match for fear of destroying their wagons, were first made by Roman war chariots. Since the chariots were made for or by Imperial Rome they were all alike in the matter of wheel spacing.
Thus, we have the answer to the original questions. The United State standard railroad gauge of 4 feet, 8.5 inches derives from the original specification (Military Spec) for an Imperial Roman army war chariot. MilSpecs and Bureaucracies live forever.
Regards,
the goat
GearDrivenSteam wrote:I've always thought that the measurement was taken from the center of the top of the rails. Seems like that would make the most sense.
Do you know how they measure the gauge out in the field? I didn't think so because if you did, you wouldn't ask the above question.
They use a steel track gauge, that is placed between the rails. So much easier than centre to centre.
See my comment above about railfans not knowing how real railways work.
However, you do raise in interesting point regarding centre to centre. I have a theaory that we arrived at 4ft 81/2inches because the original rails were measured centre to centre. It was only later that they began to measure the inside gauge, hence the oddball 4ft 81/2".
Nothing to do with that old urban myth abpout Roman chariots and the width of horses rear ends.
Standards S-3.2 and 4.2 have what is called an abstraction or abstract inference to it. Standard S-3.2 (Trackwork: Standard Scale) sets the maximum track gage for HO-Scale at .672 inches/17.1 millimeters. Standard S-4.2 (Wheels: Standard Scale) sets the maximum check gage at .605 inches/15.37 millimeters. I will gee-go-guarantee you that if you build to minimum track gage (.649 inches/16.5 millimeters) and you use minimum check gage for your wheels and you do not use minimum flange widths you will, very shortly learn how to spell d-e-r-a-i-l-m-e-n-t-s-a-t-f-l-a-n-g-e-w-a-y-s.And that's all the rubbish I have for the day there, rogertra; certainly hope that I didn't use too big a words or too long a sentences. Before closing I do have to ask, which is better, Atlas or Kato?SEE DICK!SEE DICK RUN!SEE DICK RUN FAST.SEE ROGERTRA ASK, "WHAT DOES ABSTRACT MEAN? WHAT DO HISTORY MAJORS AND COMPUTER PROGRAMMERS DO? WHAT DOES THINKING ABSTRACTLY MEAN?"
This old CPR track spec diagram clearly shows gauge being measured inside the rails.
http://railways-atlas.tapor.ualberta.ca/cocoon/atlas/Charts-5-3-9/
(use the icons at the bottom of the diagram to expand the diagram or move the image around)
Regards
Ed
rtpoteet1 wrote: SNIP NRMA Gooblygook. SEE DICK!SEE DICK RUN!SEE DICK RUN FAST.SEE ROGERTRA ASK, "WHAT DOES ABSTRACT MEAN? WHAT DO HISTORY MAJORS AND COMPUTER PROGRAMMERS DO? WHAT DOES THINKING ABSTRACTLY MEAN?"
SNIP NRMA Gooblygook.
SEE DICK!SEE DICK RUN!SEE DICK RUN FAST.SEE ROGERTRA ASK, "WHAT DOES ABSTRACT MEAN? WHAT DO HISTORY MAJORS AND COMPUTER PROGRAMMERS DO? WHAT DOES THINKING ABSTRACTLY MEAN?"
What on Earth are you babbling about?
We were discussing how real railways measure gauge, "Between" the rails, not NMRA standards.
How was disussing what history majors and computer progammers? What have they got to do with a railway measuring gauge?
Wierd.
No, I didn't know how they were measured in the field. I didn't ask a question, either. I just said what would make sense to ME.
rogertra wrote: GearDrivenSteam wrote:I've always thought that the measurement was taken from the center of the top of the rails. Seems like that would make the most sense. Do you know how they measure the gauge out in the field? I didn't think so because if you did, you wouldn't ask the above question. They use a steel track gauge, that is placed between the rails. So much easier than centre to centre. See my comment above about railfans not knowing how real railways work. However, you do raise in interesting point regarding centre to centre. I have a theaory that we arrived at 4ft 81/2inches because the original rails were measured centre to centre. It was only later that they began to measure the inside gauge, hence the oddball 4ft 81/2". Nothing to do with that old urban myth abpout Roman chariots and the width of horses rear ends.
rtpoteet1 wrote: Standard S-3.2 (Trackwork: Standard Scale) sets the maximum track gage for HO-Scale at .672 inches/17.1 millimeters. Standard S-4.2 (Wheels: Standard Scale) sets the maximum check gage at .605 inches/15.37 millimeters. I will gee-go-guarantee you that if you build to minimum track gage (.649 inches/16.5 millimeters) and you use minimum check gage for your wheels and you do not use minimum flange widths you will, very shortly learn how to spell d-e-r-a-i-l-m-e-n-t-s-a-t-f-l-a-n-g-e-w-a-y-s.
Standard S-3.2 (Trackwork: Standard Scale) sets the maximum track gage for HO-Scale at .672 inches/17.1 millimeters. Standard S-4.2 (Wheels: Standard Scale) sets the maximum check gage at .605 inches/15.37 millimeters. I will gee-go-guarantee you that if you build to minimum track gage (.649 inches/16.5 millimeters) and you use minimum check gage for your wheels and you do not use minimum flange widths you will, very shortly learn how to spell d-e-r-a-i-l-m-e-n-t-s-a-t-f-l-a-n-g-e-w-a-y-s.
RT - AKA Purveyor of ...
I'm throwing the BS flag again. And, if you're a betting man I'll call your gee-go-guarantee for the price you name. If you actually lay a turnout using the maximum track gauge, I will guarantee derailments as the wheels consistently pick the frog with guard and wing rails set at the correct check gauge. For whatever reasons, the NMRA wheel gauge is narrower than the track gauge - they don't match as they should. In most scales/gauges, the discrepancy is about 1.5 scale inches, in HO it's actually more. Because of this, those in the know who handlay turnouts lay them to MINIMUM track gauge throughout. And these turnouts perform flawlessly. For futher discussion of the issue, see http://groups.yahoo.com/group/handlaidtrack/ and http://www.railwayeng.com/rrhints.htm Take a micrometer or calipers to your NMRA gauge for personal verification that the "track" and "wheel" gauges are different.
In the meantime, you lay your turnouts to maximum gauge, and I'll lay mine to minimum and we'll count our derailments...
yours in gauging accurately
HO! HUM!THINK I'LL START BUILDING MY NEXT SWITCHES TO YOUR STANDARDS INSTEAD OF NMRA STANDARDS! I HAVEN'T HAD A GOOD DERAILMENT IN MANY YEARS - EXCEPT ON COMMERCIALLY MANUFACTURED SWITCHES!TOMORROW I'M GOING TO MAKE A STATEMENT THAT THE EARTH IS ROUND. WHOSE GOING TO PICK A FIGHT WITH ME OVER IT????
rtpoteet1 wrote:Standards S-3.2 and 4.2 have what is called an abstraction or abstract inference to it. Standard S-3.2 (Trackwork: Standard Scale) sets the maximum track gage for HO-Scale at .672 inches/17.1 millimeters. Standard S-4.2 (Wheels: Standard Scale) sets the maximum check gage at .605 inches/15.37 millimeters. I will gee-go-guarantee you that if you build to minimum track gage (.649 inches/16.5 millimeters) and you use minimum check gage for your wheels and you do not use minimum flange widths you will, very shortly learn how to spell d-e-r-a-i-l-m-e-n-t-s-a-t-f-l-a-n-g-e-w-a-y-s.And that's all the rubbish I have for the day there, rogertra; certainly hope that I didn't use too big a words or too long a sentences. Before closing I do have to ask, which is better, Atlas or Kato?SEE DICK!SEE DICK RUN!SEE DICK RUN FAST.SEE ROGERTRA ASK, "WHAT DOES ABSTRACT MEAN? WHAT DO HISTORY MAJORS AND COMPUTER PROGRAMMERS DO? WHAT DOES THINKING ABSTRACTLY MEAN?"
Five out of four people have trouble with fractions. -AnonymousThree may keep a secret, if two of them are dead. -Benjamin Franklin "You don't have to be Jeeves to love butlers, but it helps." (Followers of Levi's Real Jewish Rye will get this one) -Ed K "A potted watch never boils." -Ed Kowal If it's not fun, why do it ? -Ben & Jerry
FYI, per the www.truthorfiction.com website, the roman chariot story is fiction. Here's the real deal according to them:
"Where did the four-foot, eight-and-a-half-inch standard originate? Gabriel says it was from a Englishman named George Stephenson. Carts on rails had been used in mines in England for years, but the width of the rails varied from mine to mine since they didn't share tracks. Stephenson was the one who started experimenting with putting a steam engine on the carts so there would be propulsion to pull them along. He had worked with several mines with differing gauges and simply chose to make the rails for his project 4-foot, eight inches wide. He later decided that adding another six inches made things easier. He was later consulted for constructing some rails along a roadway and by the time broader plans for railroads in Great Britain were proposed, there were already 1200 miles of his rails so the "Stephenson gauge" became the standard.Interestingly, the 4-foot, eight-and-a-half inch width has not always been the standard in the U.S. According to the Encyclopedia of American Business History and Biography, at the beginning of the Civil War, there were more than 20 different gauges ranging from 3 to 6 feet, although the 4-foot, eight-and-a-half inch was the most widely used. During the war, any supplies transported by rail had to be transferred by hand whenever a car on one gauge encountered track of another gauge and more than 4,000 miles of new track was laid during the war to standardize the process. Later, Congress decreed that the 4-foot, eight-and-a-half inch standard would be used for transcontinental railway."
Another excellent demonstration of why the distance is measured between the rails - ever see just how many variations in rail head profile there have been over the years? The width of the rail head is not a universal standard. The gauge is. That's why a loco that was built to run on fishbelly profile cast iron rail (eg - "John Bull") will happily run on modern rails.
Incidentally, standard gauge was originally 4'8" in Britain. The half inch was (as I recall) added some time in the 1820s-30s to prevent binding on curves.
I presume you're not designing rolling stock or track, then?
I tried to find AREA or ISO drawings, but they all charge for them. Perhaps people will take John Armstrong's word for it that it's between the rails?
http://www.sdrm.org/faqs/gauge/track-lg.gif
modlerbob wrote:In the 1:1 scale world the 4'-81/2" distance is from center of rail to center of rail, at least on the engineering drawings I work from.
Then you'll end up with track that no standard gauge rolling stock will be able to run on.
The gauge is ALWAYS measured inside the railhead. Dunno what engineering drawings you work from but I wouldn't want to be on any standard gauge track that originates from that drawing office.
I have worked on the steel gang and believe me, it's the inside measurement, every time, no exceptions, period!
selector wrote:Because the widths of the tread surface on the heads of rails varies over time and road, measuring to the centres, even in a road that has a particular pattern, will result in errors greater than if the measurement was taken at the flange surfaces of the heads, or the insides. Measuring to the insides is controllable with only one dimension, while dealing with track widths adds another order of EOM (error of measurement).
Exactly. I tried to say that, but it didn't work. I had a thought once about the 4 feet 8 and a half. I think I read that an early shot at wheel on rails put the flanges on the outside. It wasn't long before it was realized this was clearly the wrong way to go, so they flipped the flanges to the inside. Now the part I'm making up. Say this was England, and they started out with track that was pretty narrow (maybe a little under two inches), layed them with an outside gauge of a nice even five feet. When they flipped the wheels, they wouldn't have wanted to change the track, so by total happenstance, the onside gauge was on the order of 56.5 inches, and a standard was born. Please remember, I made this up, I have no basis for this except my own imagination, and some experience in making lemonade from lemons.