How were loading gauges chosen?

[PMN1]

How was the loading gauge decided on during the building of the UK's railways?

 

[HSTEd]

Essentialy every company originally came to decisions on the smallest possible loading gauge they could get away with and still take the traffic they were aiming for.

Later on more standardised gauges were decided upon by the Railway clearing House but numerous gauges persisted that are only now being normalised as part of a programme begun by BR at WCML electrification and continued through to the present day.

 

[WatcherZero]

Its a tradeoff also between the volume and weight you can carry (wider tracks the better) and how far it takes to make a corner (the narrower the better).

 

[Joseph_Locke]

Its a tradeoff also between the volume and weight you can carry (wider tracks the better) and how far it takes to make a corner (the narrower the better).

WZ - OP implied loading gauges (e.g. vehicle size) not track gauge?

In the early years, the only passenger traffic that was considered was the landed gentry in their carriages lashed atop flat wagons. Given a platform height of 3' (a nice round number) plus the height of a typical horse drawn carriage (say about 9') plus a foot of forward thinking gives you the height, and the width is virtually a given for similar reasons.

Network Rail's suite ranges from W6A (though which most coaching stock, locomotives, non-container wagons and engineering trains will fit, to (currently) W12, which allows for square containers.

It is surprising that rail vehicles of today's proportions, designed to fit through structures designed and built 180 years ago, are still actually a usefull size; that said, the Hastings Line and Maryport & Carlisle are two of the many exceptions to this, at various points in time requiring special vehicles.

 

[yorksrob]

The Tonbridge - Hastings route had a much narrower loading gaugue than usual for many years as pirate builders had constructed four of the tunnels with too few layers of bricks lining them. The South Eastern Railway had to insert the missing layers, leading to a narrower than usual width.

The issue was solved in the mid 1980‘s when the line was singled through those tunnels.

 

[PMN1]

Given Brunel planned for carriages to have their wheels outside the the body of the coach, what loading gauge was he thinking of?

 

[Ironside]

Given Brunel planned for carriages to have their wheels outside the the body of the coach, what loading gauge was he thinking of?

I think that the wheels were widely spaced and placed on the outside primarily to maximise speed rather than for maximising loading guage.

To answer the OP it was initially loadingguage was build no larger than necessary to minimise costs, then as technology improved a larger loading guage became appealing.

I wonder what gauges would be chosen if the railways were to be built today, I suppose HS2 plans answer that.

 

[Murph]

I wonder what gauges would be chosen if the railways were to be built today, I suppose HS2 plans answer that.

I'm not sure that's really true. What already exists, and has been done before is pretty much always going to influence what is done next, when it comes to engineering. No matter how much emphasis is placed on doing a "clean slate" design, engineers will always remember (some of) what has gone before. There is also the fact that they will be considering how to maximise their investment in the design, so that will include considering how it can be used elsewhere (e.g. on existing HS lines across Europe).

 

[Ironside]

I'm not sure that's really true. What already exists, and has been done before is pretty much always going to influence what is done next, when it comes to engineering. No matter how much emphasis is placed on doing a "clean slate" design, engineers will always remember (some of) what has gone before. There is also the fact that they will be considering how to maximise their investment in the design, so that will include considering how it can be used elsewhere (e.g. on existing HS lines across Europe).

Good point, I had not thought of that.

 

[PMN1]

I think that the wheels were widely spaced and placed on the outside primarily to maximise speed rather than for maximising loading guage.

Oh I understand that, just wondering what size carriages and wagons on his track gauge would have been....not much different from pictures i've seen but hard to tell.

 

[edwin_m]

Good point, I had not thought of that.

Besides, adopting European loading gauge and other standards means that HS2 can order standard European trains and various other components, avoiding the costs and risks of using non-standard and bespoke designs.

The limiting factor on loading gauge is probably loss of stability in high crosswinds. Increasing the track gauge would allow a wider loading gauge for the same degree of stability.

I think the Stephensons had a pretty good idea, at least by the time of the Liverpool and Manchester, that all the railways would eventually join together. Either that or they just built each railway to the same standards they used for the last one. As the Stephensons and their pupils designed so many of the early railways (Great Western excepted) the later engineers would almost always have been extending one of the Stephenson routes or aiming to connect to one.

Hence all the railways in Britain (Great Western again excepted) ended up with moreorless the same loading gauge, give or take a few inches.

Another interesting question is how and why mainland Europe ended up with a loading gauge that is moreorless universal but bigger than the British one. I've read somewhere that it was due to state funding involving less penny pinching and lower population density leading to fewer structures being needed, but I'm not sure I buy that.

One would expect that the British engineers would have built more of what they knew, as they did with running on the left in France, and the others would have followed. Clearly something bigger was introduced at some stage, possibly after intervention of the state. But with the European countries being pretty fractious at the time I don't think they would have got together to agree standards, nor do I think the invasions that went on would have resulted in really wide scale forced adoption of the standards used by the invaders. Does this mean there was a lot of rebuilding later to make everything interwork?

 

[Manchester77]

Do we know what the IEP gauge will be called? Like the mark IIIs are C3 gauge (23 metre) so what will 26 metre be C5 or will it adopt a Wx style classification?

 

[Joseph_Locke]

Do we know what the IEP gauge will be called? Like the mark IIIs are C3 gauge (23 metre) so what will 26 metre be C5 or will it adopt a Wx style classification?

It will be called (as it already is) "IEP"

You're confusing vehicle kinematic envelopes (KEs) with "W" series infrastructure gauges. IEP (should such a thing ever come to pass) will have to be cleared to run on each proposed route seperately. A 26m vehicle will create large centre throws, which will preclude it from operating on some tightly-curved routes.

By the way, C3 isn't a gauge, just a set of guideline dimensions. There are no routes or vehicles officially classified in this way (no matter what the stencils on the coach ends say).

 

[Manchester77]

Thanks for clarifying I wasn't exactly clear on everything so thanks

 

[WatcherZero]

WZ - OP implied loading gauges (e.g. vehicle size) not track gauge?

Considered it was relevant when talking about initial choices of infrastructure design, carriages in those early days were about the same size as a horse drawn cart either with two end axles or a central pair of axles as they started off as horsedrawn rail carriages, it wasnt until 1874 that they started even using bogies at all rather than fixed axles. Having issues with loading gauge and longer vehicles clipping lineside structures pf earlier profiles came later.

 

[LNW-GW Joint]

Isn't the reason for broad gauge in Russia/Iberia because the local military were afraid of invasions?
Breaking the gauge was as much a defence as a technical policy.
Similar to the British military refusing to accept the early Channel Tunnel plans in the 1880s because it might make it easier for the French to invade.
The Irish case is very odd because you would have thought they would follow GB practice, and higher speed was hardly the issue.

I was surprised to find that early German and Austrian railways had left hand working, because they were designed by British engineers (Leipzig-Dresden, Vienna-Silesia Nordbahn etc) and the first locos came from Robert Stephenson in Newcastle.
Germany standardised on right-hand drive when it got organised, but Austria, while mostly right-handed, still has some left-hand routes.
Austria also had left hand drive on its roads until Hitler took over in 1938.

 

[Ironside]

Isn't the reason for broad gauge in Russia/Iberia because the local military were afraid of invasions?
Breaking the gauge was as much a defence as a technical policy.
Similar to the British military refusing to accept the early Channel Tunnel plans in the 1880s because it might make it easier for the French to invade.
The Irish case is very odd because you would have thought they would follow GB practice, and higher speed was hardly the issue.

I was surprised to find that early German and Austrian railways had left hand working, because they were designed by British engineers (Leipzig-Dresden, Vienna-Silesia Nordbahn etc) and the first locos came from Robert Stephenson in Newcastle.
Germany standardised on right-hand drive when it got organised, but Austria, while mostly right-handed, still has some left-hand routes.
Austria also had left hand drive on its roads until Hitler took over in 1938.

I think the Russian/Iberian guages were chosen for their own merits rather than defence but certainly defence was one of the key reasons for not changing at a later period. With the Irish rail I think it was again just a case of choosing a guage that was appropriate at the time, and being a island with no onward rail connections their has not been sufficient motivation to change them.

Interesting that Austria still has some left hand running track.

 

[talltim]

A lot of lines in the US were built to various broad gauges, and then standardised.
There too they have problems with differing loading gauges, with much work, especially in the east to allow double-stacks to run, but even before then there were lines that had limited clearances for the larger boxcars that came in the 40s and 50s

 

[Lockwood]

http://www.snopes.com/history/american/gauge.asp

Claim: The United States standard railroad gauge derives from the original specification for an Imperial Roman war chariot.

Seems relevant

 

[Wyvern]

http://www.snopes.com/history/american/gauge.asp

Claim: The United States standard railroad gauge derives from the original specification for an Imperial Roman war chariot.

Seems relevant

The joke when I was young was that it was the length of George Stephenson's walking stick.

The answer is probanbly more prosaic. It just happened to be the wheelbase of the wagons that were in use on Killingworth wagonway.

Elsewhere, however, wagonways varied greatly in their width. Many were constructed by Benjamin Outram, who generally built them at 4' 2",though one of his earliest., the Little Eaton Gangway was originally 3' 6" later converted to 4' 0"
--- old post above --- --- new post below ---
Even "standard" gauge lines varied in the beginning. Of the three meeting at Derby, the B&DJR was 4'9" since it was to join the London & Birmngham (4'8½") with a bit added "to allow for wheel play", the North Midland (a Stephenson line) was 4'8¾", while the Midland Counties (not a Stephenson line) was 4'8½"

 

[snowball]

I seem to remember reading something in the 1980s to the effect that BR civil engineers had recently reduced the track gauge from 1435 to 1432mm for reasons of their own (which I forget) without consulting the mechanical engineers.

 

[Gwenllian2001]

The joke when I was young was that it was the length of George Stephenson's walking stick.

The answer is probanbly more prosaic. It just happened to be the wheelbase of the wagons that were in use on Killingworth wagonway.

Elsewhere, however, wagonways varied greatly in their width. Many were constructed by Benjamin Outram, who generally built them at 4' 2",though one of his earliest., the Little Eaton Gangway was originally 3' 6" later converted to 4' 0"
--- old post above --- --- new post below ---
Even "standard" gauge lines varied in the beginning. Of the three meeting at Derby, the B&DJR was 4'9" since it was to join the London & Birmngham (4'8½") with a bit added "to allow for wheel play", the North Midland (a Stephenson line) was 4'8¾", while the Midland Counties (not a Stephenson line) was 4'8½"

What has any of this got to do with the Loading Gauge?

 

[Wyvern]

I was following on from this post.

http://www.snopes.com/history/american/gauge.asp
Seems relevant

 

[Trog]

I seem to remember reading something in the 1980s to the effect that BR civil engineers had recently reduced the track gauge from 1435 to 1432mm for reasons of their own (which I forget) without consulting the mechanical engineers.

I think it was the late 1960's early 1970's rather than 1980, that the gauge was changed from 4'-8 1/2" to 1432mm. Then in the late 1980's early 1990's it changed from 1432 back to 143 5/ 4'-8 1/2".


On loading gauge I seem to remember that the height used for British loading gauges was that needed to clear the chimney of an early locomotive called Royal George.

 

[TheEdge]

But with the European countries being pretty fractious at the time I don't think they would have got together to agree standards, nor do I think the invasions that went on would have resulted in really wide scale forced adoption of the standards used by the invaders

I think we often forget quite how bad Europe still was at that time. Napoleon was still cavorting around Europe at the start of the 19th century. Germany and Italy were yet to even come into existence and wouldn't until the second half of the century.

Saying that it would be interesting to know how and why 4' 8 1/2" spread out of the UK so comprehensively (to non colonial places)

 

[Yew]

Saying that it would be interesting to know how and why 4' 8 1/2" spread out of the UK so comprehensively (to non colonial places)

In most cases i imagine it would be because we built, advised or provided rolling stock for most early railways

 

[Joseph_Locke]

I think it was the late 1960's early 1970's rather than 1980, that the gauge was changed from 4'-8 1/2" to 1432mm. Then in the late 1980's early 1990's it changed from 1432 back to 143 5/ 4'-8 1/2".

Above and following are nothing to do with loading gauges, vehicle gauges, structure gauges or W gauges, but anyway:

Changing from 1435mm (4' 8.5") to 1432mm (4' 8.375") was an attempt to manage hunting (periodic lateral oscillation of rail vehicles at speed) at even higher speeds.

However, it was found that it just increased the frequency of hunting rather than reducing its effect, so we went back to 1435mm (4' 8.5") and revised the wheel profiles instead. 5F40 anyone?

 

[PMN1]

When railways were built in Europe, did they more or less copy the UK loading gauge and rebuild later on or were they bigger to begin with?

 

[Wyvern]

I dont know but there is point that many of Europe's railways were intended to facilitate the movement of troops and equipment, whereas the UK's were built to move goods mainly coal.
If a railway was seen as a national necessity, patriotism could be invoked to take them wherever the builders wanted to go.

Also Europe was able to see the problems Britain had and avoid them. Note how in the UK, the ECML is so much straighter than other lines.

 

[Manchester77]

When railways were built in Europe, did they more or less copy the UK loading gauge and rebuild later on or were they bigger to begin with?

A lot of Europe railways were destroyed during WWII so could be rebuilt to different standards