What if 7ft gauge had become the standard?

[kevinlms]

One things for sure, the LNWR would have been very unhappy. It and it's predecessors were very much against the broad gauge and went to a lot of effort to avoid break of gauge locations.

 

Not quite sure what the alleged advantage is meant to be, because the coaching stock and wagons, weren't really that much wider - certainly not the 2ft 3 1/2in the you might expect.

[Kris]

1 hour ago, phil-b259 said:

 

The issues with freight are generally HEIGHT not width!

 

There are a number of 'broad gauge' bridges that have had to be rebuilt to accommodate overhead wires or freight as a result.

 

Also you should note that the USA copes fine with standard gauge despite the loading gauge allowing grater widths (as well as height)

I accept that bridges etc might need rebuilding. My reasoning for more freight would have been the ability to side load given extra stability. 

[kevinlms]

5 minutes ago, Compound2632 said:

 

But it didn't work. It's abandonment was principally down to commercial pressures but there were sound engineering reasons why it was less successful in the long run than Stephenson gauge - the concept was not valid and much of the engineering detail was flawed - the baulk road being the prime example, being too rigid. But again, Brunel shouldn't take too much stick for that as early on everyone thought a rigid foundation was desirable - hence the stone blocks used on many early lines - until Locke showed that the more yielding road obtained with transverse timber sleepers gave a ride.

Brunel also made other mistakes with railways, the Atmospheric Railway was a huge diversion and many of the locos allowed to run on his track, were very ordinary to say the least.

The standard gauge railways, mostly spent their efforts in building better locos and gradually improving them.

At the same time, why would others take the first broad gauge locos seriously? Locos like Hurricane, were just a money pit. It needed Daniel Gooch to design conventional locos, before the GWR had decent locos.

[Curlew]

One consequence of broader gauges is that narrow gauge may become more likely for lightly used lines. Think of Ireland or India, for example. We may have ended up with 7ft and lots of 3ft gauge feeder lines.

[Titan]

15 minutes ago, Kris said:

I accept that bridges etc might need rebuilding. My reasoning for more freight would have been the ability to side load given extra stability. 

 

You can side load on standard gauge with no issue whatsoever. How do you think the channel tunnel works?  There were side loading vehicles for motorail services too.

[Compound2632]

4 minutes ago, kevinlms said:

At the same time, why would others take the first broad gauge locos seriously? Locos like Hurricane, were just a money pit. It needed Daniel Gooch to design conventional locos, before the GWR had decent locos.

 

Well, Robert Stephenson in the first instance, with Gooch as his disciple. 

 

3 minutes ago, Curlew said:

One consequence of broader gauges is that narrow gauge may become more likely for lightly used lines. Think of Ireland or India, for example. We may have ended up with 7ft and lots of 3ft gauge feeder lines.

 

... which were the first casualties of road competition in Ireland, the need for transhipment being the really weak point. I believe it's the case that the more important narrow gauge lines in India have been converted to Indian standard gauge.

[Titan]

42 minutes ago, Compound2632 said:

 

But before you can even consider such ideas, the validity of the premise is in question.

 

Well I managed to consider such ideas without questioning the premise so it has already been done, proving that it is not necessary to question it.  I found it quite easy not to question it too.

[Allegheny1600]

I was always under the impression (I don’t know where from) that the broad gauge allowed greater running speeds, it was only much later that the Stephenson gauge allowed similar speeds.

 

Had the 7’ gauge prevailed in the UK, would it have remained confined to the western parts of the nation or would the other companies have converted? (Probably not due to costs)

What about new railways being built? Possibly - if they had at least one BG connection.

 

One thing would have been very interesting, how would models have represented the broad gauge?

Probably doable in the original model scales but once you go smaller than 7mm, then what!?

 

Now to retire into my bunker!

John

[Compound2632]

2 minutes ago, Titan said:

Well I managed to consider such ideas without questioning the premise so it has already been done, proving that it is not necessary to question it.  I found it quite easy not to question it too.

 

Ah, but one should always question the premise of the question to expose the underlying assumptions.

[phil-b259]

25 minutes ago, Kris said:

I accept that bridges etc might need rebuilding. My reasoning for more freight would have been the ability to side load given extra stability. 

 

The experiences of the USA, etc proves this is totally unnecessary!

 

On the other hand the loading gauge (and distances between parallel tracks) DO have a big impact on freight carrying capability  and are the things you need to worry about - which have sod all to do with the track gauge.

 

Naturally if you have a narrow track gauge then you might also pick a narrow loading gauge and closely spaced parallel tracks to reduce land take and construction costs - but that doesn't mean a particular gauge in itself is the limiting factor.

[Steven B]

16 minutes ago, Kris said:

I accept that bridges etc might need rebuilding. My reasoning for more freight would have been the ability to side load given extra stability. 

 

The Channel Tunnel "Le Shuttle" trains side load sideways onto standard gauge wagons. Cars, coaches and HGVs all load from the side. BR's Motorail also used side loading. Several dedicated wagons were built such as this one:

https://www.departmentals.com/departmental/96453

Additionally, a number of Mk1 GUV were rebuilt to allow for side loading for the last gasp efforts to keep Motorail alive.

 

British work-shops were turning out locos to a range of gauges in the years that followed the birth of the railways so theoretically there was nothing to stop the first German or French railways for operating a larger gauge from the start - it's not as though there'd be through running from Liverpool-Manchester-Berlin!

 

A more interesting question is why gauges larger than 5'-5'6" never succeeded. Even in the likes of Russia or Australia where you have massive expanses of open space on which to build there's clearly some limiting factor. I'd guess that what we have now is the best compromise between axle loads and cargo volume. There's not much point in having a large volume (available from a larger gauge) to fill if you max out on axle loading.

 

 

 

Steven B.

[phil-b259]

1 minute ago, Allegheny1600 said:

I was always under the impression (I don’t know where from) that the broad gauge allowed greater running speeds, it was only much later that the Stephenson gauge allowed similar speeds.

 

Had the 7’ gauge prevailed in the UK, would it have remained confined to the western parts of the nation or would the other companies have converted? (Probably not due to costs)

What about new railways being built? Possibly - if they had at least one BG connection.

 

One thing would have been very interesting, how would models have represented the broad gauge?

Probably doable in the original model scales but once you go smaller than 7mm, then what!?

 

Now to retire into my bunker!

John

 

If the Government had not stepped in then in theory you could have got an 'Australian situation' develop with two gauges in use for a considerable period of time.

 

However unlike Australia the UK is a small country and there would be huge pressure from industry and politicians to standardise - and if it hadn't been done by WW1 I expect the Government would have forced the issue.

 

 

[phil-b259]

1 minute ago, Steven B said:

 

The Channel Tunnel "Le Shuttle" trains side load sideways onto standard gauge wagons. Cars, coaches and HGVs all load from the side. BR's Motorail also used side loading.

 

 

 

The Euro tunnel vehicle carrying wagons have jacking systems which are deployed at the terminals thus keeping the wagons (which are even wider than European loading gauge) steady as vehicles drive on and off.

 

Stock built for UK domestic use was much narrower and did not need this measure.

[kevinlms]

4 minutes ago, phil-b259 said:

 

If the Government had not stepped in then in theory you could have got an 'Australian situation' develop with two gauges in use for a considerable period of time.

 

However unlike Australia the UK is a small country and there would be huge pressure from industry and politicians to standardise - and if it hadn't been done by WW1 I expect the Government would have forced the issue.

 

 

The fact it took Australia a long time to think about standardising track gauge, was because each state had it's own government and many early decisions had to go via London!

[Titan]

I do wonder if a proportionately longer wheelbase for bogies would be required for higher speeds?  increasing the width of the rails with the same wheelbase would most likely increase the probability of bogie hunting, something that might not have been considered in the early days as it might not have been such an issue with the speeds of the time.  it might also have been an issue for conicity of the wheel treads.  A wider gauge means a greater difference in distance travelled for the same radius of curve, requiring more of a cone to accommodate it.  And a steeper cone angle is more prone to hunting. 

 

I suspect that the idea of higher speeds being possible was based on the idea of the width giving extra stability, but when standard gauge can handle cornering forces well in excess of passenger comfort, so much so that even on standard gauge tilt is required to take advantage of it, then any extra speed capability of broad gauge due to it's width is somewhat moot.

[kevinlms]

3 minutes ago, phil-b259 said:

 

The Euro tunnel vehicle carrying wagons have jacking systems which are deployed at the terminals thus keeping the wagons (which are even wider than European loading gauge) steady as vehicles drive on and off.

 

Stock built for UK domestic use was much narrower and did not need this measure.

Surely it's better for stock used day in day out, to employ a proper jacking system (automated?), rather than a 'once per day' operation for a relatively small number of vehicles.

[Titan]

2 minutes ago, kevinlms said:

Surely it's better for stock used day in day out, to employ a proper jacking system (automated?), rather than a 'once per day' operation for a relatively small number of vehicles.

 

On the Motorail vehicles I worked on jacks were not necessary, although when you are only loading comparatively light vehicles from passenger height platforms I suppose the offset load as they went on was pretty minimal.

[Flying Pig]

1 hour ago, Compound2632 said:

 

Try drawing out a force diagram.

 

Assuming we're interested in the centripetal acceleration needed to get the train round the curve and not the torque about the CofG needed to make the train fall over, I still can't see how it makes a difference.

[Titan]

7 minutes ago, Flying Pig said:

 

Assuming we're interested in the centripetal acceleration needed to get the train round the curve and not the torque about the CofG needed to make the train fall over, I still can't see how it makes a difference.

 

I can see it making a difference, a wider train is likely to be heavier per unit length, i.e. a broad gauge train of the same capacity is likely to be shorter - although that is assuming a bigger loading gauge as was the case in broad gauge days- - perhaps not so relevant now.  Therefore the track would be under a heavier load, but for a shorter time as the train passes.

Edited September 7, 2021 by Titan

[Compound2632]

3 minutes ago, Flying Pig said:

Assuming we're interested in the centripetal acceleration needed to get the train round the curve 

 

Well, that's provided by a combination of the coning of the wheels and the cant of the track; a greater proportion of the weight will be on the inner rail with, indeed, some transverse force on the outer rail. But these are relatively insignificant compared with...

 

5 minutes ago, Flying Pig said:

the torque about the CofG needed to make the train fall over,

 

... the transverse forces on the railhead as the train rolls, pitches, and bounces along the track, even on the straight.

 

(One does not see more robust rail fixings used on the outside of a curve.)

[Stubby47]

12 minutes ago, Titan said:

I do wonder if a proportionately longer wheelbase for bogies would be required for higher speeds?  increasing the width of the rails with the same wheelbase would most likely increase the probability of bogie hunting, something that might not have been considered in the early days as it might not have been such an issue with the speeds of the time.  it might also have been an issue for conicity of the wheel treads.  A wider gauge means a greater difference in distance travelled for the same radius of curve, requiring more of a cone to accommodate it.  And a steeper cone angle is more prone to hunting.

 

Would this have given rise to an earlier adoption of independent wheels, rather than a fixed axle ?

 

https://www.talgo.com/technological-principles

[kevinlms]

47 minutes ago, Titan said:

 

I can see it making a difference, a wider train is likely to be heavier per unit length, i.e. a broad gauge train of the same capacity is likely to be shorter - although that is assuming a bigger loading gauge as was the case in broad gauge days- - perhaps not so relevant now.  Therefore the track would be under a heavier load, but for a shorter time as the train passes.

Expanding your thoughts in a different direction.

 

As the London Underground has been built to standard gauge, how would the system be today, if 2 important differences had been made in the early days.

 

I give you 1/ Larger dimensioned trains, both in width and height - thus allowing more passengers to fit.

2/ Larger platform surfaces, which would stop the sometimes dangerous overcrowding of platforms, which causes stations to temporarily close.

 

I think these factors are far more important than track gauge.

[TheQ]

Selecting 7 ft gauge would not have meant rebuilding all the bridges etc. why? because 7ft is within the Loading gauge of 99% of standard gauge lines. Yes the track would have been wider but the loading gauge for the prebuilt lines would not have changed.. What may have needed changing would be platform edges, but that is a comparatively minor cost..

 

Ask Southern.. Their tiny tunnels are still 4ft 8.5 inches even though the loading gauge is much smaller..

 

So Mallard could still have been built same size.. just with, all inside cylinders..

 

So what else would have happened?

Less uneconomic lines would have been built due to cost,

GWR would have had a great advantage in their area with full size wagons,

Later some of the main lines, would have been expanded to the full Brunel Loading gauge, east and west coast main lines first.

 

PS I did seriously consider building a model railway on this premise..

..

Edited September 7, 2021 by TheQ

[Jeremy Cumberland]

29 minutes ago, kevinlms said:

As the London Underground has been built to standard gauge, how would the system be today

Well, the first line was built to broad gauge, and Baker Street circle line platforms are very little changed. I cannot really see it making a lot of difference in respect of fitting more people onto trains or space on platforms.

 

7 foot gauge tube trains would be bigger overall (but perhaps not wider, or not much at any rate) and of course tunnelling costs would be higher, because you would need a greater diameter to accommodate the track gauge, but perhaps the biggest change would be the increase in the minimum radius, which might have been a game changer, for cut and cover lines as well as tube lines. As other people have mentioned previously in this thread, the existance of a standard 7 foot gauge would make it more likely for other railways that could not accommodae the larger curves being built to narrow gauge, and I can easily imagine tube railways (where through running was not generally envisaged) being built to something like four foot.

[Mike_Walker]

When I did a PTS course at Crewe it was taken by an exile from Somerset.  Apart from myself, all the others were rookies to the rail industry so the course started by explaining what is meant by Up and Down then the tutor went on to explain Fast and Slow lines.  

 

He paused and explained that "in some parts of the country they don't use Fast and Slow but Main and Relief.  So why's that, Mike?"

 

Without pausing for thought I replied that "on the Great Western our Relief lines usually have higher permissible speed than the Fast lines up here in narrow gauge country so the term Slow seems inappropriate".

 

"Exactly" came the reply " if everyone had listened to Brunel we could have had high speed trains years ago without all this tilting malarkey"!   

 

And before anyone starts, yes, I know that's not strictly true but it caused us both a good laugh and left more than a few students completely perplexed.

Edited September 7, 2021 by Mike_Walker