How were loading gauges chosen?

[edwin_m]

There were many trains across Europe even before WW2 so I think there was a lot of compatibility in structure gauges even then.

 

[PMN1]

Has anyone ever out a guestimate to the extra cost of building to a larger loading gauge from the start...for example how much extra it would have been to build to what became the UIC C gauge?

 

[SemaphoreSam]

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

Thaaat's it! Brunel's stick was longer than Stephenson's. Sam

 

[Joseph_Locke]

Has anyone ever out a guestimate to the extra cost of building to a larger loading gauge from the start...for example how much extra it would have been to build to what became the UIC C gauge?

Never compared new build directly, but other than the obvious increase in bridge materials for the higher soffit and wider spans, there would be little percentage difference except in tunnels. To build an electrification-ready UIC "C" single-bore tunnel with full structure clearances for all speeds would increase the cross sectional area by about 100%, compared with a typical one of my own era.

A subtle additional cost would be for the additional length of apporach works for bridiges over the railway, as UIC "C" is very much taller; this may have caused different alignments to be chosen in any case.

 

[Metrailway]

There were many trains across Europe even before WW2 so I think there was a lot of compatibility in structure gauges even then.

Indeed. What many in Britain call the 'Berne' gauge was standardised before WWI. The proper name for the loading gauge is PPI or Gabarit passe partout international which means pass everywhere international. The PPI gauge was a compromise between the loading gauges of the French railways (which had the most restrictive loading gauges in the Continent) and other railways such as VDEV members which had more generous loading gauges. There were still lines in France which did not meet the PPI gauge standard as late as the 1930s. PPI gauge had a width of 3150mm and a (central) height of 4280mm

A common misconception is that the London Extension of the GCR was built to 'Berne' gauge - this is false as the Extension railway was completed in 1899 whilst the Berne conference occured in 1912.

In 1922, the UIC was formed (the Big 4 were members) and soon after three loading gauge standards were produced: UIC A - slightly bigger than PPI, UIC B, and UIC C which were based on railways in central Europe. All UIC loading gauge standards have the same width: 3150mm.

 

[yorksrob]

A common misconception is that the London Extension of the GCR was built to 'Berne' gauge - this is false as the Extension railway was completed in 1899 whilst the Berne conference occured in 1912.

Was the GCR built to the equivalent of Berne Gauge, even though, strictly speaking, it didn't exist at the time ?

 

[edwin_m]

To build an electrification-ready UIC "C" single-bore tunnel with full structure clearances for all speeds would increase the cross sectional area by about 100%, compared with a typical one of my own era.

Leaving aside that you famously avoided tunnels whenever possible... how much of this difference is to do with the UIC C gauge and how much to do with the greater speed?

 

[Ironside]

Was the GCR built to the equivalent of Berne Gauge, even though, strictly speaking, it didn't exist at the time ?

I recal that it was, as the intention was to connect to a channel tunnel and therefore run trains directly onto the continent.

 

[pablo]

Wasn't Yerkes going to run his GC trains from Baker Street down the Metropolitan Railway out to the south-east? In which case, did he have plans to enlarge the town end of the Met?

There was one through carriage from Birkenhead to Paris via this route, so I recall. Wasn't there to view it at the time, mind you!

 

[Murph]

Wasn't Yerkes going to run his GC trains from Baker Street down the Metropolitan Railway out to the south-east? In which case, did he have plans to enlarge the town end of the Met?

There was one through carriage from Birkenhead to Paris via this route, so I recall. Wasn't there to view it at the time, mind you!

The Met eastbound from Baker Street was built fairly large to start with, although I'm not sure if that's sufficient for what you mention above.

http://www.railforums.co.uk/showpost.php?p=1378339&postcount=8:

The "A" stock was very wide , build to the "Met" gauge (remember Edgware Rd - Farringdon was broad gauge when built !) - this caused problems when towing them north for the refurb in the 1980's as a special gauging run had to be done.

 

[Wyvern]

Thaaat's it! Brunel's stick was longer than Stephenson's. Sam

Who?

 

[edwin_m]

Wasn't Yerkes going to run his GC trains from Baker Street down the Metropolitan Railway out to the south-east? In which case, did he have plans to enlarge the town end of the Met?

There was one through carriage from Birkenhead to Paris via this route, so I recall. Wasn't there to view it at the time, mind you!

If it was anyone it would have been Watkin, who was a big cheese in the GC, Met, South Eastern and the Channel Tunnel project. The Met between Paddington and Farringdon was built to broad gauge so the tunnels may be a bit wider.

 

[pablo]

I think you are right. My memory fades. Yerkes was the tube moghul. Watkin the Internationalist.

 

[Caertroia]

If it was anyone it would have been Watkin, who was a big cheese in the GC, Met, South Eastern and the Channel Tunnel project.

Edward Watkin. Also a director of the Compagnie des Chemins de Fer du Nord, builder of Paris Gare du Nord.

 

[Trog]

I recal that it was, as the intention was to connect to a channel tunnel and therefore run trains directly onto the continent.

I think you will find that the GC London Extension was built to a normal British loading gauge, to match the rest of their system.

 

[yorksrob]

I recal that it was, as the intention was to connect to a channel tunnel and therefore run trains directly onto the continent.

Ah cheers. Tearing it up begins to look even more short sighted !

 

[Metrailway]

Was the GCR built to the equivalent of Berne Gauge, even though, strictly speaking, it didn't exist at the time ?

Do you mean the same size as the loading gauge agreed in Berne in 1912? If so, no the GCR was not built to this loading gauge.

I believe there was a loading gauge conference (held in Berne) in the late 1880s/early 1890s and I believe an international loading gauge was agreed and came into force in 1891. However, I'm unsure whether it was ever implemented as I have read a French technical railway book (published in 1899) and it shows a loading gauge diagram of the same 1891 specification but it is labelled as 'proposed'. Then again, my French is very poor.

Assuming that there was an 1891 loading gauge specification, the GCR's London Extension did not meet the 1891 spec. I believe the 1891 spec was 3100mm wide and (central) height 4150mm.

But many French railways also did not make the 1891 spec. Many railways of the Compagnie des Chemins de Fer du Nord were initially built with British height platforms and as a result had a very similar loading gauge to many British railways. Any Channel Tunnel built in that era would have met the lines of Compagnie des Chemins de Fer du Nord. It may be possible that the London Extension loading gauge matched (or was very similar to) the Compagnie des Chemins de Fer du Nord loading gauge but without actually seeing loading gauge documents of the Compagnie des Chemins de Fer du Nord, it is impossible to confirm this.

The London Extension's loading gauge was 9ft 3in (~2819mm) wide and 13ft 5in (~4089mm) (centre) high (the arc begins at 10ft 5in) which was slightly more generous than most British railways of the era. For comparison W12 is ~ 8ft 6in wide 9ft 6 in height; C3 is ~ 8ft 12in wide 12ft 5in high (arc begins at 10ft 1.25in). If the London Extension still existed in 2013, it probably could have carried high cubed ISO containers on standard flats with ease.

Due to the very high engineering standards employed on the London Extension railway, the railway was built for future expansion to a four track railway. If there was a need to expand the London extension to a continental loading gauge, it would have been very easy to do so.

 

[Ploughman]

The London Extension's loading gauge was 9ft 3in (~2819mm) wide and 13ft 5in (~4089mm) (centre) high (the arc begins at 10ft 5in) which was slightly more generous than most British railways of the era. For comparison W12 is ~ 8ft 6in wide 9ft 6 in height; C3 is ~ 8ft 12in wide 12ft 5in high (arc begins at 10ft 1.25in). If the London Extension still existed in 2013, it probably could have carried high cubed ISO containers on standard flats with ease.

Do you really mean 9ft instead?

 

[Metrailway]

Do you really mean 9ft instead?

I rounded 11 7/8th in to 12in without thinking. :roll:

 

[yorksrob]

Do you mean the same size as the loading gauge agreed in Berne in 1912? If so, no the GCR was not built to this loading gauge.

I believe there was a loading gauge conference (held in Berne) in the late 1880s/early 1890s and I believe an international loading gauge was agreed and came into force in 1891. However, I'm unsure whether it was ever implemented as I have read a French technical railway book (published in 1899) and it shows a loading gauge diagram of the same 1891 specification but it is labelled as 'proposed'. Then again, my French is very poor.

Assuming that there was an 1891 loading gauge specification, the GCR's London Extension did not meet the 1891 spec. I believe the 1891 spec was 3100mm wide and (central) height 4150mm.

But many French railways also did not make the 1891 spec. Many railways of the Compagnie des Chemins de Fer du Nord were initially built with British height platforms and as a result had a very similar loading gauge to many British railways. Any Channel Tunnel built in that era would have met the lines of Compagnie des Chemins de Fer du Nord. It may be possible that the London Extension loading gauge matched (or was very similar to) the Compagnie des Chemins de Fer du Nord loading gauge but without actually seeing loading gauge documents of the Compagnie des Chemins de Fer du Nord, it is impossible to confirm this.

The London Extension's loading gauge was 9ft 3in (~2819mm) wide and 13ft 5in (~4089mm) (centre) high (the arc begins at 10ft 5in) which was slightly more generous than most British railways of the era. For comparison W12 is ~ 8ft 6in wide 9ft 6 in height; C3 is ~ 8ft 12in wide 12ft 5in high (arc begins at 10ft 1.25in). If the London Extension still existed in 2013, it probably could have carried high cubed ISO containers on standard flats with ease.

Due to the very high engineering standards employed on the London Extension railway, the railway was built for future expansion to a four track railway. If there was a need to expand the London extension to a continental loading gauge, it would have been very easy to do so.

Thanks for a very detailed and interesting explanation.

 

[PMN1]

A subtle additional cost would be for the additional length of apporach works for bridiges over the railway, as UIC "C" is very much taller; this may have caused different alignments to be chosen in any case.

Higher centre of gravity??