ideal gauge

[martinvk]

Leaving aside the historical origins of standard gauge, the need to interface with existing infrastructure and if cost was not a factor, what would be an ideal gauge if railways were to be invented today? Would different uses influence this: regular passenger and freight, highspeed passenger and freight etc. 1.435m seems a rather arbitrary number, 4'-8.5" is hardly any better.

 

[johnwhelan]

I'd go with 7 feet or roughly the metric equivalent. It would offer better stability for high speed and for double stacked containers.

Cheerio John

 

[bendorsey]

The narrower the gauge the sharper the curves are that can be used. This is why much of Colorado originally used 3 ft gauge instead of std ga. A std ga RR couldn't get into the steep mountains to the gold and silver but a 3 ft gauge one could. Equipment is smaller, cost is a bit less, as is ride stability.

As for a choice for today it would depend on the level of technology at the time. If we could go directly to high speed rail then a wider gauge would be appropriate but if its a new invention that wouldn't normally be the case.

Interesting question tho,

Ben

 

[martinvk]

The matter of stability would appear to be related to the ratio of gauge width to the overall height of the equipment over the rails. As the width increases, the equipment can get taller without changing the tendency to tip over. So is it only because people and their goods have to fit that certain wagon sizes are preferred which in turn limits the range of desirable gauges?

As for sharper curves, is that not related to the overall shortness of narrow gauge cars compared to standard gauge? True they need a smaller ROW but that's a cost factor, not part of this equation.

 

[NIARTcar]

The height isn't necesarily the major determining factor of its stablity, it plays into the larger "center of gravity" concept, in short it depends on where the car's mass is located. In theory, any problems with instability due to small footprints (ie gauge) can be overcome by placing the majority of a cars mass in the most efficient place depending on the size of it's footprint. [Physics=Fun:hehe: ]

cheers,

 

[martinvk]

The height isn't ... , in short it depends on where the car's mass is located. ...[Physics=Fun:hehe: ]

cheers,

True, but if changing the center of gravity is advantageous for one gauge, it would also be for others. All things being equal, a stack of containers, or cargo of any height, would be more stable on a wider gauge than a narrower one.

Besides stability, are there any efficiency differences? Aside from the obvious greater tare mass, would tare mass scale linearly with increasing gauge? Would a larger wagon leave less of the bearing capacity of the rail available for cargo?

 

[NIARTcar]

True..... However, then it becomes a matter of how you want to transport said cargo, space efficiency, aerodynamic properties, etc...... ultimately it comes down to the railroads being able to pack more loads into less cars...... In theory, then narrow gauge users, would account for this advatage of packing efficiency, bu concentrating their loads in a specific region of the car rather than stacking, but as molecular theory tells us two molecules cannot occupy the same space (and frankly I like my bread not squished thank you ). So, depending on the relationships and effects that both train train length and height have on fuel consumption, I would assume somewhere within that data would be your answer. Greater length= more surface area= more drag; increase of height= exposed drag surfaces= more drag.... its also necesary to take into consideration the ability to streamline cargo. (which brings us back to load shape)

cheers

 

[Jananton]

Without the history of railways or, if we consider the best way for mass transport today, I wonder if tracks would be the choice. With advancing technology in mind I think some kind of frictionless transport would be the way to go. Allthough there would be some form of guidance, tracks in the way as we know it wouldn't come in the picture anymore. An interesting inbetween step was taken in the Paris Metro together with the Michelain tyre company three quarters on in the previous century. Metro trainz rode on concrete tracks, their bogeys guided by smaller horizontal wheels along concrete higher tracks at the sides. Today we could lose those wheels all together and use magnetic fields instead. This would also mean that the concept of locomotives would become redundant. Since the tracktion power would be by magnets in the concrete tracks instead of in the actual train.

Much too modern for me btw. I'll stick to steam instead.:hehe:

Greetings from nighttime Amsterdam,

Jan

 

[pommie]

Most rail cargo is by containers and they also travel by road, so the loading width is restricted by the road loading width, the only way to increase that traffic is to load two side by side, 10 foot (3mtr) gauge anyone :hehe:
Weight wise containers would never overtax rail, even double width and stacked due to their relatively light weight.
Heavy bulk cargo's do not even push the loading restrictions of SG before being to heavy, so no advantage going wider or higher there.
The only advantage I can see, for the railroad company's, in going wider and/or higher is for a more stable ride for passenger traffic and light bulk loads, wood chips, sugar beats etc, a lot of cost for what is really minimal traffic.
One big advantage for the average person if they went to a 10' (3mtr) gauge would be that the double stacked container trains would be either half as long or half the number of trains, good news for anyone using the level crossings

As an aside, going wider might be needed if ever they start using nuclear power in locomotive's

If starting out now a rail company would still be limited by the containers width and hight, so it would be around 5ft/1.5m or 10ft/3mtr, also I know you said cost was not to be factored in, but can you imagine how strong a bridge would have to be to support iron ore trains with a loading width of around 12ft, the current SG ore wagons are 200 tonnes gross, that would be over 400t without increasing hight, increase the hight and erm 1,000t wagons anyone.

Cheers David

 

[pommie]

Just had another thought the wider the gauge the more wear there is on a given curve, to explain, the wheel on the outside has to travel farther than the wheel on the inside, causing one or the other to slip (or break the axle), slip=wear and friction, and the axles will have to be stronger to be able to withstand the torque twist, more non-profit weight to drag around, so a more powerful locomotive is needed for a given load.
So on one hand (narrow) you have stability concerns and on the other (broad) increased wear and friction.

You would also have to factor in non rail infrastructure, while money is not a factor for you, it is for others, bridges going over the broader tracks would need to be a lot longer and stronger, meaning you have to explain to the roads department that their bridge building costs are going to skyrocket :hehe:

Cheers David

 

[cascaderailroad]

Well an 18" gauge track would have an awfully unstable center of gravity at 100+ mph, and the cars would be narrow, and not be able to be tall. And if you had a gauge larger than Broad Gauge, I am sure that the physics and friction would get kind of rediculous as well. As being that the English wagon wheel gauge history goes, it was carried over to trains. And science and physics calculates that the center of gravity and stabillity at somewhere abouts around 4' 8-1/2" is a stable gauge, in regaurds to physics.

I guess the main scientific reasoning is that a person is @ 6' tall, and passenger car inside heights must be @ 8' tall, making the outside car heights off the railhead @ 14' or more. now factor the width of a car so that it can carry people and cargo ergonomicly, and you could arrive at a stabillity factor where the ideal wheelbase gauge should be @ 5', so as to prevent tipping.

Four foot would be too small...and six foot would be too big. And the 17th century wagon-maker rocket scientists came pretty darn close to being right on the money. Imagine the Pueblo Colorado High Speed Test Track Facility testing the tipping charactoristics of high speed Engish horse drawn wagons on curves...The Queen would have been very displeased if her carriage tipped over on account of being too narrow, and a Caddilac or Hummer size English carriage would be much too cumbersome.

The Acme Super Train (on DLS) with it's super broad track gauge is rediculous...unless you were transporting extremely wide, not of this world cargo: like the Starship Enterprize parts, or small cruise ship width passenger trains.

 

[teddytoot]

Most rail cargo is by containers and they also travel by road, so the loading width is restricted by the road loading width, the only way to increase that traffic is to load two side by side, 10 foot (3mtr) gauge anyone :hehe:

See here. You will find other references to this project if you google.