Talk:Standard gauge

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Contents 1 best gauge? 2 break-of-gauge 3 gauge 4 Accuracy of gauge 5 Ideal gauge 6 Standard Gauge (Rail gauge#Britain) 7 Metric

[edit] best gauge?

I understand the whole thing about interoperability...but what if, from the very beggining, everybody had used broad gauge? Wouldn't that have been better?

[edit] break-of-gauge

Perhaps this section should be moved to break-of-gauge?? --Peter Horn 17:26, 23 March 2006 (UTC)

[edit] gauge

While it is a shock to see one's work go through the wringer, Morven has re-edited the "Idea Gauge" article nicely so as to retain all its original essential material. :-)

Um, my Dad insists that standard gauge is 4' 8 5/8" and not 4' 8 1/2". He spent all his life overseeing the laying of track, but all I see everywhere is 8 1/2. Is his memory faulty or did some people jump to the conclusion that 5/8 = 1/2? --WiseWoman 23:54, 2005 Feb 26 (UTC)

The 1435mm are 56.5" while 56 5/8" would be about 3mm (about 0.2%) more. It cannot come from the difference of the different ft units; other ft units (where 1 ft does not equal 12") are either longer or much shorter (as far as I can tell). Perhaps the difference comes from another point: the standard gauge is 56 1/2", but in practice the tracks need to be slighter further apart to compensate for tolerances. The track distance may also change with temperature. --Klaws 11:36, 18 November 2005 (UTC)

On very sharp curves of say 200 metres or less, there may be "gauge widening" of say 12mm (1/2 inch). This helps prevent the flanges of the wheels biting into the rail and causing noise and wear.

Tabletop 00:21, 21 November 2005 (UTC)

No need to widen the gauge to 4' 8 5/8" on tangent track, because the measure from flange exterior to flange exterior is 4' 7¾" and back to back of the wheels is some 4' 5⅛" (N American practice). Peter Horn 00:01, 19 June 2007 (UTC)

There is a comment in the article that the relationship of standard gauge to the old Roman standard is legendary. However, it had been my understanding that early railway builders used rolling stock that was built similar to contemporary stage coaches and wagons. Builders used the same jigs and patterns for these early railway vehicles that they had in building the stage coaches and wagons. While these may have varied from 4'8.5", in general they used this "gauge" in order to allow the vehicles to use the ruts in roads, which were pretty consistent over the centuries from the Roman days.

[edit] Accuracy of gauge

How accurate must the gauge of the rails be laid to prevent derailment?

Well the rail head is about 50mm or 75mm wide, and the wheels are also about 50mm or 75mm wide.

Don't quote me, but I think that this means that the gauge could vary + or - 12mm and things might work OK, but don't quote me.

A gauge measured in inches seems to have a coarser tolerance than the same gauge measured in millimetres.

A separate issue is gauge widening on sharp curves. Where a curve is sharper than about 200m radius, the gauge may be widened up to about 25mm (1 inch) to allow for the fact that the wheels are not parallel to be rails but are at an angle.

Tabletop 06:35, 11 Apr 2005 (UTC)

I guess that faster trains need tighter tolerances than slower ones. For example, the maximum allowed speed for the ICE depends on the "quality" of the rails it's running on. The most important "quality" factor is of course the curve diameter, but it is also known that lateral movement is a big problem at higher speeds. I guess that was also the reason for the infamous "bistro hum" of the early ICE models, which was elimininated by a new wheel design, where lateral movement would be absorbed and damped (this new design was abondoned after the biggest train desaster in german history, where such a wheel was torn apart). --Klaws 13:00, 18 November 2005 (UTC)

Nitpick: It's not the biggest, it's #3 (or lower): 1939 two trains collided in Genthin, 278 killed. And 1967 in Langenweddingen 140 were killed when a train transporting petrol collided with an express, see List of rail accidents. - Alureiter 11:15, 24 January 2006 (UTC)

There weren´t a Standard Gauge in County Durham when Stephenson started building railways. For example the railway that passed just outside the windov of the room he was born in is wider. 5'½" if i remember correctly. The first gauge that Stephenson started building locos for was 4 and 8 [4 ft 8 in (1,422 mm)]. He stuck to it for convenience as he admitted under oath.

Votre tres humble etc. Stefan spett

Accuracy depends on the back to back distance between the wheels and the width of the grooves at switches and crossovers. Peter Horn 02:32, 21 May 2007 (UTC)

[edit] Ideal gauge

The big problem with 1435mm is not limited speed or limited cargo weight capacity, but passenger wagons. With the usual 2x2 seats (open interior) or 1x4 seat (2nd class cab layout), there remains very little width for center or side aisle. When the food cart is being pushed along the corridor that is really inconvenient for people. If the gauge was a bit wider, the waggons could be wider too and a lot more comfortable. Quite probably the decline of popularity in train travel over much of the world has something to do with the confined space standard gauge railway waggons offer to patrons.

This is not a problem with rail gauge because car body width is virtually independent from the rail gauge.

For instance, Soviet elektrichkas (rail gauge 1520 mm, only 89 mm wider than Stephenson's gauge) have 2x3 seat layout.--Achp ru 18:22, 20 June 2006 (UTC)

One of the more recent train networks is the japanese's Shinkansen. In 1960? They chose standard gauge track for their wide body width - 2x3 seating trains. This is annother example of where the loading gague:track gauge ratio is quite high, yet high speeds and reasonable stability can be acheived.

Perhapes broad gauge would be a major advantage, even necessary, for even bigger loading gauges. But such super wide trains would probably produce too much extra drag to be worth the greater capacity they would provide.

This is not to suggest that standard gauge is "the perfect gauge" only a specialised train engineer and economist could attempt to calculate the answer to that question, but it does prove that standard gauge is "good enough", for there is no significant need for broader gauges. Evan Roberts

This whole section seems a little pedantic to me. More importantly though, it dances around, but never makes, them most important point that everything is a trade-off. Narrow gauge has advantages (lower cost, tighter turns for low speed, lighter, lower material cost.) and disadvantages (less stable on soft ground, lower capacity, etc.) likewise with broad gauge. Regarding the size of the car, it is definitely not independent of the gauge. The cosine law's a bitch if your aspect rations stray too far from 1:1 or have significant overhang. Ask any mechanical designer (me) and he will tell you that the most efficient design (volume per pound) will require an approximately square car on a wheels spaced at least as wide as the car. Remember, weight is a very important factor in car design.

A good example of this trade off relationship is in Japan. JR and subways are narrow gauge to reduce materials, cost, allow navigating the narrow cities and mountains of japan etc. Standard gauge was chose for the shinkansen for larger cars (passenger comfort) and higher speed due to a more stable track. The cost was higher and the routes limited but even with the hit to interoperability (a very serious issue in Japan) they made this decision for a reason. So that seems to go against the article which emphases that all gauges are about as good. This needs to be fixed. jcp 04:15, 6 April 2007 (UTC)

...(less stable on soft ground, lower capacity, etc.) likewise with broad gauge. Oops...Broader gauges would be even more stable than standard gauge! That is apparently why 5 ft 6 in (1,676 mm) was choosen for the Bay Area Rapid Transit#System details. Peter Horn 00:21, 19 June 2007 (UTC)

Even though I understand nothing about railway gauges it seems to me that this section needs some work. I can learn more from the discussion page than from the article itself. Currently the article mentions that broad gauge leads to more stability, but most of the section gives reasons (or indications) why gauge is not so important, and certainly less important than interoperability. I would suggest that somebody who understands this stuff

• adds some quantitive statement about stability, such as "doubling the size of the gauge would mean that trains could go 50% faster", or "a 10% smaller gauge would necessitate 20% wider curves, assuming the same speed" or whatever the correct numbers are.
• adds remarks about the inherent disadvantages of broader gauges (such as cost, or possibly the limited weight an axle can carry). Why were the first railways not built with a gauge as wide as a street?

Thank you. --The very model of a minor general 15:38, 16 August 2007 (UTC)

[edit] Standard Gauge (Rail gauge#Britain)

Hi Peter,

It is beginning to look like the statements that 4 ft 8½ in (1,435 mm) was a de facto standard prior to the Liverpool and Manchester Railway are unsupported statements. Baxter (1966: P 56) states that there was no standard gauge for horse railways, but there were rough groupings. In the north of England none were less than 4ft. Wylam, built before 1763, was 5ft 0in; as was John Blenkinsop's Middleton Railway - the wikipedia article says 4ft 1in, and Baxter (1966: P 56) says the old 4ft plateway was relaid to 5ft so that Blenkinsop's engine could be used.

Baxter (1966: P 56): Others were 4ft 4in Beamish or 4ft 7.5in (Bigges Main and Kenton and Coxlodge). Stephenson favoured 4ft 8in for waggonways in Northumberland and Durham and used it on his Killingworth line. The Hetton and Springwell waggonways also used the gauge. Stephenson's Stockton and Darlington railway was built to 4ft 8in and used it for fifteen years before being changed to 4 ft 8½ in (1,435 mm).

Whishaw (1842): The Chester and Birkenhead railway, authorised on 12 July 1837, was 4ft 9in (page 54); The Eastern Counties Railway, authorised on 4 July 1836, was 5ft 0in (page 91); London and Blackwall Railway, authorised on 28 July 1836, was 5ft 0in (page 260); The London and Brighton Railway, authorised on 15 July 1837, was 4ft 9in (page 273); The Manchester and Birmingham Railway, authorised on 30 June 1837, was 4ft 9in (page 303); The Manchester and Leeds Railway, authorised on 4 July 1836, was 4ft 9in (page 319); the Northern and Eastern Railway,authorised on 4 July 1836, was 5ft 0in (page 363). The 4ft 9in railways were intended to take 4 ft 8½ in (1,435 mm) gauge vehicles and allow a running tolerance. The rest of the railways in England, excluding the Great Western Railway were 4 ft 8½ in (1,435 mm) gauge. I've not included Scotland, Wales or Ireland.

From this the so called standard gauge could be regarded as 4ft 8in to 5ft 0ft.

• Baxter, Bertam (1966). (The Industrial Archaeology of the British Isles. Stone Blocks and Iron Rails (Tramroads) Newton Abbott: David & Charles.

• Whishaw, Francis (1842). The Railways of Great Britain and Ireland: Practically Described and Illustrated. Newton Abbott: David & Charles Reprints. (published 1969) ISBN 0-7153-4786-1.

Pyrotec 20:13, 13 June 2007 (UTC)

Copy and paste from User talk:Peter Horn Peter Horn 23:46, 18 June 2007 (UTC)

Wylam was a 5 mile long colliery trackway running to pits near Wylam village. It opened in 1748, was rebuilt in 1808 and a tram engine used from 1812. (Baxter, 1966:P150).Pyrotec 08:09, 25 June 2007 (UTC)

[edit] Metric

Why does this article claim that standard gauge is 1435 mm? It is not. It is 4 feet 8.5 inches! Converting the correct length into Metric does not give an exact value (to one decimal place is 1435.1 mm) - so the Imperial system should be used. Yes, it is only a fraction different, but a fraction different is not the same.

As well as this, in the UK and US, Imperial is used mainly anyway, so a change is necessary.

In conclusion, it should say: Standard gauge is 4 feet 8.5 inches (appox. 1435 mm) Btline (talk) 14:08, 1 April 2008 (UTC)

Actually NO. You are correct that 4 feet 8.5 inches is appoximately 1435 mm and standard gauge was 4 ft 8.5 in. It appears that BR modified it to 1,432 mm. I'm not sure when this happened, but it was at least 10 years ago. The reference comes from Simmons, Jack and Biddle, Gordon (Edrs.) (1997). The Oxford Companion to British Railway History: from 1603 to the 1990s. Oxford: Oxford University Press.) ISBN 0-19-211697-5. Page 523 (under: "track gauge"). Yes I know that this is the 1st of April. It is definitely not an April Fools trick.Pyrotec (talk) 16:39, 1 April 2008 (UTC)

So you are saying that the track is now slightly narrower than 20 years ago? Hmmmmm - I can't see BR replacing all the track. It is easy to see that a lot of track has not been touched in 30 years! Also- why would an imperial using company, in an imperial using country switch? Btline (talk) 17:06, 1 April 2008 (UTC)

Check the reference; BR is (was) not a company and the UK is a metric country and has been since the 1960s (?), appart from road lengths, speed limits, bottles of milk and beer in glasses. Have you never read about market storeholders being prosecuted for selling, e.g. bananas by the pound, rather than the kilo? Think about it, they may not necessarily change the track spacings, just make the wheels 4 mm closer together. I will try and find another reference for you.Pyrotec (talk) 17:18, 1 April 2008 (UTC)

It was a major investment, but the EU demanded it. Harmonisation, you know. All the tracks were adjusted to make the gauge 3.1 mm smaller. The worst part was that the EU demanded that both tracks be moved by 1.55 mm, instead of just moving one track 3.1 mm. (Political compromise between the left-wing and right-wing factions - the left-wing faction wanted the left track moved, and - you know...) --RenniePet (talk) 17:20, 1 April 2008 (UTC) Just my feeble attempt at humor. --RenniePet (talk) 18:49, 2 April 2008 (UTC)

I should have guessed it was the EU! Btline (talk) 17:23, 1 April 2008 (UTC)

I suspect that the bit about moving each track (or should that be rail) by 1.55 mm is an April Fools joke. Moving one rail by 3 mm would suffice. The April 2007 version of the Railway Safety Standards Board Group Standard for track gauge is here [1]. The limits on straight track are 1426 to 1465 mm for up to 20 mph working, down to 1430 to 1450 mm for 95 mph and above working. The average appears to be 1440 mm; but check for yourselves. It seems that standard rail gauge is the width of the wheel flanges; and that the track is slightly wider, depending on whether the track is straight, or curved,the line speed, cant, cant deficiency, etc.Pyrotec (talk) 18:38, 1 April 2008 (UTC)

Look- I regard moving any rails as a definate' joke. Proof? Why can steam trains built in pre-60s still run? It seems all to be garbage, and I won't belive it until I read a source.

Well, surely all this boils down to is that the Metric system value is different every time you see a source. What is clear is that standard gauge is 4 feet 8.5 inches. This is what is understood in the UK, and prob much of the world! Why not just call it so! Btline (talk) 17:07, 2 April 2008 (UTC)

The online PDF document linked to above does make it pretty clear for the UK the standard gauge is 1435 mm.

"2.9 Track gauge

2.9.1 Nominal track gauge

2.9.1.1 New and relaid track shall be designed to give a nominal track gauge of 1435 mm."

--RenniePet (talk) 18:49, 2 April 2008 (UTC)

PS. My excuse for trying to be funny was not so much the date (1 April) but the fact that I, having an engineering background, find it very funny to be arguing about differences of +/- a few millimeters in the positioning of rails approx. 1.5 meters from each other. I'm guessing that in real life a variation of up to a couple of centimeters is considered to be OK. I mean, like, +/- 3 mm: you can hardly see it with the naked eye! --RenniePet (talk) 19:01, 2 April 2008 (UTC)

Sheesh, a millimetre is a much finer measurement than an inch. Do we have sources that say 4 feet 8.5 inches is an exact measurement? Maybe it's only norminal, maybe 1435mm is more accurate. Anyway, 3 mm is an acceptable safety factor and tolerance. --Kvasir (talk) 16:15, 3 April 2008 (UTC)

One eight of an inch in proper units.Pyrotec (talk) 16:18, 3 April 2008 (UTC)

I was just responding to btline's statement that "1435 mm" is not a correct representation of "1435.1 mm" even though the measurement is meant to be norminal than anything. --Kvasir (talk) 16:25, 3 April 2008 (UTC)

Woops. I agree entirely. Pyrotec (talk) 16:32, 3 April 2008 (UTC)

Look, it am still not buying this. Some tracks in the UK havn't been touched for years! And I come back to the main point - steam (i.e. 100 yr old) trains can still run on the mainlines. This provs that it is still 4 ft 8½. This exact figure is different to the mm value. Has some 1st April trickery been going on here? Btline (talk) 17:02, 3 April 2008 (UTC)

I'm beginning to wonder if your continued insistence that something is wrong is an expression of your sense of humor? :-)

In real life, the rails are never exactly the correct distance apart, no matter what "correct" is defined to be. Nor are the wheels on railway cars exactly the correct distance apart. There is a certain leeway +/- a centimeter or two which is considered acceptable, and everything works within these tolerances.

So you can proclaim that standard gauge is nominally 4' 8.5" or 1435 mm or 1432 mm, without batting an eyelid or modifying a single rail or boggie. These differences are so small (do you realize how little 3 millimeters is?) that it makes no difference in the real world. --RenniePet (talk) 19:08, 3 April 2008 (UTC)

I thought that even a small 3 mm distance could be too much. Btline (talk) 19:10, 3 April 2008 (UTC)

There is a difference between the perfect world and real life engineering, such as in civil construction. Accuracy to a centimeter is usually sufficient in areas like underground utilities and elevation in surveying. Next time you are at a rail crossing, you can see the rails have visible sag whenever the wheels run over an unsupported rail section. Built-in flexibility and tolerance are everywhere. It's not like building a watch where accuracy to a fraction of a millimeter would be required. --Kvasir (talk) 20:07, 3 April 2008 (UTC)

Why don't you read the RSSB Group Standards references? Do you really know more about the subject than they do! The tolerance on rail separation depends on line speed, cant, cant deficiency, whether the track is straight or curved, curve radius, etc. You were full prepared to accept that it was an EU directive, why are you unwilling to read the Railway Safety and Standards Board Ltd group Standard? Ring them up if you can't read pdf files.Pyrotec (talk) 19:26, 3 April 2008 (UTC)