GCR Loading Gauge

[jfowkes]

Hi all,

I've read on other threads that contrary to received wisdom, the GCR was not built to "continental loading gauge". I'm wondering about the details of this.

I have specific questions, but please do discuss around the topic.

• Is this only because the meaning of that term has changed between when the GCR was built and today? i.e. it was built to what was considered continental gauge at the time? Or was it not even true then?
• Wikipedia says "Watkin's Great Central Main Line was designed to a continental European loading gauge" (emphasis mine).
  • Is this true? Was the design for a continental gauge, whatever the meaning of that was at the time? But the construction was different from design?
  • Should the wiki page for the GCR be changed? (one of the references for the above is a book about railway ghost stories, which doesn't fill me with confidence about its authority)
• Is it possible to determine what UIC gauge the GCR would have been equivalent to?

 

[swt_passenger]

AIUI the conference to establish the first generally understood “European gauge” took place some time after the GC was opened. It seems to have been built to a larger structure gauge than usual for GB at the time, but that doesn’t necessarily seem to be equivalent to a future continental standard.

I remember a uk.railway discussion about this many years ago, and the thread was full of dates, dimensions and comparisons:

https://groups.google.com/forum/m/#!msg/uk.railway/v8Ynb_0kNS8/Lw0V9B-J_zkJ

 

[Senex]

This gets discussed all over the place at regular intervals and there was indeed a massive discussion here not too long ago. In brief, as swt_passengers says, there was no such thing as a "European gauge" or "continental gauge" at the time. The MS&L London Extension was built to the then-current Board of Trade regulations which were considerbaly more detailed by the 1890s than they had been in earlier years and which did in some cases provide for more generous clearances than had been accepted in earlier construction.

 

[jfowkes]

Ah, sorry, I did search on here but failed to find anything particularly detailed. Thanks for the link to google groups.

 

[MarkyT]

Whether or not other structures were larger than earlier UK railways, the platforms would not have been compatible with anything continental.

 

[edwin_m]

Many years ago I was responsible for arranging testing in the UK of a UIC-gauge track recording coach destined for a Continental client. The GC would only have been able to do it by removing the platform copers temporarily (and charging us for the privilege). Nene Valley didn't require any special works although a couple of places were subject to severe speed restrictions due to tight clearances.

 

[Flying Phil]

One of the first steam locomotives on the GCR was the Norwegian "King Hakon" 2-6-0 (?) and that had to have the platform coping stones "shaved" in places to gain clearances for the cylinders.
There was a good article on the issue of "Continental Loading Gauge" and the GC in a recent issue of "Main Line" - the GC magazine.

 

[RLBH]

The GCR loading gauge wasn't significantly bigger than other UK railways, and actually smaller than quite a few. The only UK railways to achieve European loading gauge were the GWR's broad gauge lines, and perhaps the Dingwall and Skye Railway. The latter was designed to be able to move fishing boats between the East and West coast, so the original crossing loops (both of them) have a 'six foot' that's nearer fifteen feet, and I don't believe there are any overbridges on the line.

There's an interesting page on historical loading gauges here:
https://www.devboats.co.uk/gwdrawings/loadinggauges.php

 

[InOban]

Maybe not when built, but a quick check on Google maps shows the there are now two in Kyle, two near Duirinish, at least one in plockton, and I think another at Stromeferry. Indeed maybe the idea of boat movements would be between Strome and, actually I'm not sure where the boats would have been relaunched.

 

[RLBH]

Indeed maybe the idea of boat movements would be between Strome and, actually I'm not sure where the boats would have been relaunched.

The Dingwall and Skye railway only ran to Stromeferry. By the time the Kyle of Lochalsh Extension Railway came along to finish the job, the idea had been given up.

I imagine that the boats must have been planned to be relaunched at Dingwall - it's about half a mile from the station to the harbour, which wouldn't be excessive for a twice-a-year operation. A siding alongside the Dingwall Canal wouldn't be unreasonable, but one doesn't seem to have been provided.

 

[RPM]

In answer to the OP's original question re Wikipedia - it is wrong and it should be changed, although I see the offending paragraph has already been flagged up by Wikipedia as being potentially factually inaccurate.

The GCR "continental loading gauge" issue is clearly and demonstrably a myth, and yet it inexplicably remains a deeply held one amongst many people - especially those nescient dreamers who believe the GC main line should be reopened instead of building HS2.

 

[RLBH]

In answer to the OP's original question re Wikipedia - it is wrong and it should be changed, although I see the offending paragraph has already been flagged up by Wikipedia as being potentially factually inaccurate

The reliability of Wikipedia is neatly demonstrated by the fact that it's been flagged for at least three years, during which time someone has found original loading gauge drawings - which aren't considered an acceptable source as they were merely produced by the people who built the thing, not by an independent author.

 

[Taunton]

The GCR loading gauge wasn't significantly bigger than other UK railways, and actually smaller than quite a few. The only UK railways to achieve European loading gauge were the GWR's broad gauge lines,

I had always understood that although the broad gauge had a greater structural gauge width, it did not have the continental height - continental double deck vehicles do not fit on the Western, regardless of platform edges.

The GWR King locomotives were built right out to the limits of the structure gauge, and were particularly tight in places, including chimney height under bridges, and I believe there have been one or two incidents with them in recent times running on the national network where everything else gets through OK but they have grazed the underside of something. Actually, with 26^ diameter cylinders (but four of them) they do not stick out quite as much at low level as say a Hall, with (two) 30" cylinders. I can certainly remember seeing a Hall on Taunton shed with a cylinder cover grazed - it had probably been somewhere on the Southern!

Strangely much of the broad gauge passenger stock did not take advantage of this for body width, which can be seen in photographs to be as narrow as contemporaries, but with substantial continuous steps/running boards sticking out at the bottom for boarding from platforms, which were decidedly lower than current standards.

http://www.british-towns.net/england/southwestern/bristol/redcliffe/album/gwr-broad-gauge

It's a general fallacy in many non-specialist accounts that because it was a broad track gauge it followed that the stock is wider. The two are actually unconnected. You even find descriptions of Russian trains being "roomier because they have a wider track gauge". Such accounts normally overlook African railways of 3'6^ or even metre gauge with locomotives larger than anything in Britain.

 

[swaldman]

It's a general fallacy in many non-specialist accounts that because it was a broad track gauge it followed that the stock is wider. The two are actually unconnected. You even find descriptions of Russian trains being "roomier because they have a wider track gauge". Such accounts normally overlook African railways of 3'6^ or even metre gauge with locomotives larger than anything in Britain.

Japan also. Metre(ish?) gauge, and wide EMUs that one can see out of the front of. It's a weird feeling standing at one side looking forward and realising that the track is all the way over there ----> !

 

[RLBH]

I had always understood that although the broad gauge had a greater structural gauge width, it did not have the continental height - continental double deck vehicles do not fit on the Western, regardless of platform edges.

The GWR King locomotives were built right out to the limits of the structure gauge, and were particularly tight in places, including chimney height under bridges, and I believe there have been one or two incidents with them in recent times running on the national network where everything else gets through OK but they have grazed the underside of something. Actually, with 26^ diameter cylinders (but four of them) they do not stick out quite as much at low level as say a Hall, with (two) 30" cylinders. I can certainly remember seeing a Hall on Taunton shed with a cylinder cover grazed - it had probably been somewhere on the Southern!

It seems that really generous loading gauges on the GWR were exclusive to the broad gauge lines, and once they were converted to narrow gauge these clearances weren't preserved.

 

[edwin_m]

Wasn't part of the idea of the broad gauge so the wheels could be on the outside instead of underneath? Which would imply that the bodies were not much different from the width for standard gauge.

Later broad gauge stock was most likely built with gauge conversion in mind, so the body would have been the standard width anyway. Once platforms became higher, as someone mentioned above it would be necessary to have a similar distance between the platform edge and the nearest rail on the two gauges, so that platforms would work for dual-gauge track.

 

[Journeyman]

I don't know where the "continental loading gauge" thing came from, but it appears to have been stated in a book somewhere, and was interpreted to mean "equivalent to UIC/Berne gauge" by many people. As has been pointed out, the standards were not agreed for that until 1914, and up until then the various railways in mainland Europe had their own standards. Therefore, the author of whatever book it was may have meant that the GC conformed to one of the standards prevalent in Europe at the time it was built, and this may or may not be true, but it absolutely didn't correspond to modern European main line standards as we'd understand them now.

There's no doubt whatsoever that it was generous by UK standards, simply by being built quite late in the scheme of things, and there's no disputing it was built to very high specifications, but you'd certainly not be able to run a modern European train along it, and I doubt upgrading it would have been easy either. Apparently the use of island platforms would have made it easy to use much wider stock by moving the tracks slightly further away, rather than the more expensive option of rebuilding the platform edges, but I have no idea if the other structures and tunnels would have allowed this.

There was a bridge somewhere that was notorious for getting bashed by loco tenders, so that scuppers any idea it could take taller stock than normal.

Unfortunately this misunderstanding is now so common that it's given the GCML a mythical status it's never deserved. While I find the history of the line fascinating, I'm firmly of the opinion that it was almost always a white elephant and was never actually needed, then or now. It offered no significant advantages over any of the competing routes, and away from cities already linked by existing lines it only served small towns, many of which already had stations nearby. It was entirely driven by a strong personality and competitive railway politics. In later years, it was not unknown for trains to leave Marylebone without a single passenger on board.

Quite why we should be recreating a line that never justified its construction, I don't know.

 

[swt_passenger]

Apparently the use of island platforms would have made it easy to use much wider stock by moving the tracks slightly further away, rather than the more expensive option of rebuilding the platform edges, but I have no idea if the other structures and tunnels would have allowed this.

I’d also suspect that was a ‘reverse engineered’ explanation. It might not be the real reason why they were built that way, perhaps it was just generally cheaper, avoiding footbridges. Perhaps it allowed for easier four tracking at the same gauge. But whatever the real reason it helps justify the Continental gauge myth.

 

[Journeyman]

I’d also suspect that was a ‘reverse engineered’ explanation. It might not be the real reason why they were built that way, perhaps it was just generally cheaper, avoiding footbridges. Perhaps it allowed for easier four tracking at the same gauge. But whatever the real reason it helps justify the Continental gauge myth.

I agree - it doesn't seem very convincing, given there's no evidence that other structures were accommodating. I think the four-tracking argument is stronger, but of course was never required because the line was never that busy.

Quite apart from anything else, the GC main line was attached to lots of other railways, none of which were able to take continental stock. People have argued about the ambitions to connect the line to proposed Channel tunnels, but the suggestion was going via the Met and the SECR. The Met has a surprisingly generous loading gauge - LU's A stock was very wide by UK standards - but the SECR was incredibly restricted in lots of places, and a huge amount of gauge clearance work had to be done when the Networkers were introduced.

 

[grumpyoldman01]

Institution of Civil Engineers paper no: 3209 of 1900, entitled 'The Great Central Railway Extension: Southern Division', by Francis Douglas Fox, used to be easily available to study on the internet; a search just now suggests it is only available for a payment.

From memory, this probably answers many of the questions raised about the London Extension, for it gives diagrams showing cross sections of cuttings, embankments, tunnels, etc.

I seem to recall that Fox indicates somewhere in the paper that the tops of many embankments were wider than the minimum required; they had too much spoil and had to use it somewhere!

There's a GCR loading gauge diagram comprised in volume 2 of Dow's history of the railway; however, it dates from 1895, and therefore pre-dates the construction of the London extension.

Dow also quotes the internal dimensions of Catesby Tunnel; 27' wide and 25'6'' high, so quite generous; he quotes the internal width of the London tunnels as being slightly narrower, at 26'3'' wide.

The ICE's website also makes reference to a paper by a F W Bidder, the engineer for the northern division, but I've never been able to find that as a "free" document to browse.

 

[Journeyman]

Dow also quotes the internal dimensions of Catesby Tunnel; 27' wide and 25'6'' high, so quite generous; he quotes the internal width of the London tunnels as being slightly narrower, at 26'3'' wide.

How does that compare to a typical tunnel elsewhere?

 

[Taunton]

It seems that really generous loading gauges on the GWR were exclusive to the broad gauge lines, and once they were converted to narrow gauge these clearances weren't preserved.

Not necessarily; the large Kings were restricted to a few routes only, but some of these, such as Paddington to Wolverhampton, had never been broad gauge once away from the south-east, only standard gauge.

It's described that the GCR was the last main line built, and this drove the generous structure gauge, but ignores that the GWR subsequently built a very considerable amount of main line themselves in 1900-1914; Paddington to Banbury, the Badminton line, the Swansea District and Fishguard lines, Newbury to Taunton pieces. In aggregate I think the mileage will be not far short of what the GCR had built from Annesley to Quainton Road in the decade beforehand. These were the last true main lines built, and they had no broad gauge heritage. It would be interesting to compare their structure gauges to the GCR.

 

[edwin_m]

I’d also suspect that was a ‘reverse engineered’ explanation. It might not be the real reason why they were built that way, perhaps it was just generally cheaper, avoiding footbridges. Perhaps it allowed for easier four tracking at the same gauge. But whatever the real reason it helps justify the Continental gauge myth.

I believe it was simply about cost. Having one access off a road over or underbridge is cheaper than two accesses or a footbridge, and perhaps more significantly fewer staff are needed if they can supervise trains calling on either platform face without going more than few steps from the ticket office.

A few stations (such as Loughborough) did have extra tracks on the outside of the platform tracks.

 

[Flying Phil]

I believe it was simply about cost. Having one access off a road over or underbridge is cheaper than two accesses or a footbridge, and perhaps more significantly fewer staff are needed if they can supervise trains calling on either platform face without going more than few steps from the ticket office.

A few stations (such as Loughborough) did have extra tracks on the outside of the platform tracks.

Also the smaller stations - and their overbridges (Quorn, Rothley etc), were built to accommodate the extra two tracks - when the traffic levels increased......

 

[grumpyoldman01]

How does that compare to a typical tunnel elsewhere?

Sorry, don't know.

But HS1 (Section 2)'s Register of Infrastructure can be found at:

https://www.whatdotheyknow.com/requ.../HS1 Section 2 Register of Infrastructure.pdf

and on page 21 it suggests that the width of the London Tunnels is 11' 7'' (I think!).

Does this help?

 

[Chris125]

Strangely much of the broad gauge passenger stock did not take advantage of this for body width, which can be seen in photographs to be as narrow as contemporaries, but with substantial continuous steps/running boards sticking out at the bottom for boarding from platforms, which were decidedly lower than current standards.

Broad Gauge rolling stock was wider initially, but in later years it was designed with conversion to Standard Gauge in mind - the wide running boards being one result.

 

[edwin_m]

Sorry, don't know.

But HS1 (Section 2)'s Register of Infrastructure can be found at:

https://www.whatdotheyknow.com/request/24986/response/79568/attach/3/HS1 Section 2 Register of Infrastructure.pdf

and on page 21 it suggests that the width of the London Tunnels is 11' 7'' (I think!).

Does this help?

Probably not (but thanks anyway). Tunnels on HS2 will be wider for an evacuation walkway, and tunnels on high speed lines have a larger cross-section dependent on speed, crudely so that the air the train pushes along in front of it will be able to find its way past the train rather than creating a huge pressure wave. So the tunnel itself will be much bigger than the structure gauge.

 

[MarkyT]

Japan also. Metre(ish?) gauge, and wide EMUs that one can see out of the front of. It's a weird feeling standing at one side looking forward and realising that the track is all the way over there ----> !

3' 6" 'Cape' track gauge. Early routes (blue) have a structure gauge very similar to UK Victorian era standard gauge lines, no doubt due to British expertise employed in their development. The profile also displays the charateristic UK high platform cutout below sole bar and an 'arched' roofline. Later routes (grey) are a little taller and wider, still retaining the high platform cutout, while standard gauge Shinkansen routes (green) are larger still with a straight side down to near rail level and squared off at roof level.
https://upload.wikimedia.org/wikipe...ng-Stock-Gauge-in-Japan.svg.png?1532682389424

 

[kje7812]

Not necessarily; the large Kings were restricted to a few routes only, but some of these, such as Paddington to Wolverhampton, had never been broad gauge once away from the south-east, only standard gauge.

It's described that the GCR was the last main line built, and this drove the generous structure gauge, but ignores that the GWR subsequently built a very considerable amount of main line themselves in 1900-1914; Paddington to Banbury, the Badminton line, the Swansea District and Fishguard lines, Newbury to Taunton pieces. In aggregate I think the mileage will be not far short of what the GCR had built from Annesley to Quainton Road in the decade beforehand. These were the last true main lines built, and they had no broad gauge heritage. It would be interesting to compare their structure gauges to the GCR.

Restrictions on the Kings were mainly due to their high axle loading.
Also Paddington to Wolverhampton (original route via Oxford and Birmingham) was built as mixed gauge.