Broad Gauge Railways - Good, Bad, or Indifferent?

[rbattelle]

After visiting a railroad museum recently, I had the occasion of a 10-hour car trip to ponder various railway-related trivia.



One of the things I got to thinking about was the broad gauge railway. Here and in the UK (and in most of the world) we run on the 4' 8. 5" gauge established by George Stevenson back in the early 1800s. Why 4' 8. 5"? Because that happened to be the width Stevenson used on his first coal mine rail, and he simply stuck with it. There is no engineering significance to the value. When locomotives were as small as "Tom Thumb", 4' 8. 5" was plenty.



Later (in the 1830s and 40s), Mr. I. K. Brunel built the Great Western Railway, which provided service primarily between Bristol and London. Brunel's gauge was 7' 0. 25", based on a rigorous series of calculations and experimentation that indicated this would be "the best".



In the end, Stevenson's gauge won simply on the basis of existing trackage. The 7' gauge seems to have been better - bigger locomotives (more power), smoother running, more stability.



Imagine how much less cramped passenger trains would be at 7'. Imagine how much more power could be achieved (an end to multiple-locomotive consists?).



Would it be practical to start a new railway company today with 7' gauge? Almost certainly not, but I can't help but wonder if it could be a success if sufficient investment in equipment were made to put the cost per ton-mile extremely low. I mean below standard gauge rail and far below truck freight.



Perhaps a better question is: if the broad gauge had not been legislated out of existence and had grown in direct open competition to the standard gauge, would it have eventually become the standard, with 4' 8. 5" trackage being either relegated to minor routes or eliminated altogether?



Put more concisely, would a broad gauge railway be more economical (in terms of cost per ton-mile) today than standard gauge railways are? If it were, what effect would this have on the US commercial transportation network?



I was just wondering if anyone else had any thoughts on the matter.



Ryan

 

[ACoyle]

Just an opinion here. At this point, the problem would be more physical than legal or practical. Sizes of tunnels, Amount of land available, the need to redo all the track. Also if Canada and Mexico did not do the same thing then we would not be able to cross the borders.



It does make sense that a wider guage would be more practical. It seems that it has jsut gone too far physically.



AC

 

[rbattelle]

Perhaps we "missed the boat", so to speak, on broad gauge rail. If, at the founding of the first US railway, we had chosen to break with the UK convention and adopt a wider gauge, today we could be operating with the broad standard.

Why did we choose to stick with narrow gauge? I assume it was because we came from the UK and that's what they were doing?

I mean, there's no such thing as a train that runs from Great Britain to the US coast, so starting with a clean slate means there's no need to adhere to any overseas standard.

Ryan

 

[TowPro]

I have read this several places on the internet about why 4'-8. 5"

The US Standard railroad gauge (distance between rails) is 4 feet, 8. 5 inches. That's an exceedingly odd number. Why was that gauge used? Because that's the way they built them in England, and the first U. S. railroads were built by English expatriates.

Why did the English people build them like that? Because the first rail lines in Europe were designed and built by the same people who built the pre-railroad tramways, and that's the gauge they used.

Why did "they" use that gauge then? Because the people who designed and built the tramways used the same jigs and tools that they used for building wagons, which used that same wheel spacing. Okay, why did the wagons use that odd wheel spacing? Well, when they tried to use any other spacing, the wagons were prone to breaking down on some of the old, long distance roads, because that's the spacing of the old wheel ruts.

So who built these old rutted roads? The first long distance roads in Europe were built by Imperial Rome for the benefit of their legions. The roads have been used ever since.

And the ruts? The initial ruts, which everyone else had to match for fear of destroying their wagons, were first made by Roman war chariots. Since the chariots were all made to certain specifications for or by Imperial Rome, they were all alike in the matter of wheel spacing.

Thus, we have the answer to the original questions. The United States standard railroad gauge of 4 feet, 8. 5 inches derives from the original specification (Military, as it were) for an Imperial Roman army war chariot.

But one "nagging" question still remains. Why did the design of the Roman army war chariots incorporate that specific wheelbase?

Answer:

Because the chariots were designed to be just wide enough to accommodate the back ends of two war horses.

So, the next time you are handed some odd ball specification and you assume that some horse's *** was responsible for coming up with it, you may be exactly right!

Now the twist to the story...

When you see a Space Shuttle sitting on its launch pad, there are two big booster rockets attached to the sides of the main fuel tank. These are Solid Rocket Boosters, or SRBs. The SRBs are made by Thiokol at their factory in Utah. The engineers who designed the SRBs would have preferred to make them a bit fatter, but the SRBs had to be shipped by train from the factory to the launch site.

The railroad line from the factory happens to run through a tunnel in the mountains. The SRBs had to fit through that tunnel. The tunnel is slightly wider than the railroad track, and the railroad track, as you now know, is about as wide as two horses' behinds.

So, a major Space Shuttle design feature of what is arguably the world's most advanced transportation system was determined over two thousand years ago by the width of a Horse's ***.

And you thought being a horse's *** wasn't important ??

 

[scootergmc]

I just wish we used the metric system...

 

[Vaughn MacKenzie]

TowPro what you posted is essentially true. I read that the gauge of the ruts caused by ancient Roman chariots is less than 1/4" wider than standard gauge. I've always thought it was a bit fascinating how the predominant worldwide rail gauge is an oddball number - 56. 5 inches or 1. 435 meters, LOL

rbatelle reasons why broad gauge never really took off (especially wider than 5-1/2 feet) . . . I think because curves had to be a challenge. The wide axles would not want to turn well and would tend to climb the rail if the curve is very tight and run right off the track. If you do a search or look up broad gauge on wikipedia it tells of a number of rail lines that have run or are running a broad gauge (usually less than 5-1/2 feet).

60% of the world's rail lines are standard gauge. The US had a number of odd gauges until it was standardized in June 1886. There was some 4-10" gauge in the east and RR companies had rolling stock with what they called "compromise trucks" which were wheel sets designed to ride on both gauges. Just imagine how the wheels would hunt and weave on standard gauge track. After a disastrous derailment they put the kebosh on that and it helped push the movement to standardize nationwide.

When the US converted in 1886 the RR companies worked like mad to pull up one rail, move it inward to the correct gauge, then spike it back down. The Pennsylvania RR did their entire system in 36 hours! Some didn't gauge theirs exactly right, they went for 4-9" which standard gauge equiment ran on OK. Over the years it was gradually converted to 4-8. 5" as rail lines were upgraded.

Here's another interesting tidbit - in the steam era it was common to run the gauge a bit wide on curves, and tight on the straightaways. This helped reduced hunting and weaving on straight track, and let steam engines with their long rigid wheelbases negotiate curves without wheel flanges fighting the rail.

Vaughn

 

[bmoeller]

Put more concisely, would a broad gauge railway be more economical (in terms of cost per ton-mile) today than standard gauge railways are? If it were, what effect would this have on the US commercial transportation network?

I don't much of a gain, other than more stability and wider payloads. You still couldn't carry more weight without building the rails heavier, or adding a third rail, and would the ties take it? They aren't that far apart as it is. Wider rail spacing would require wider ties, so that cost would be higher. The rail yards might need to be widened as well, to accomodate.

The possibility of wider loads may not help much, since the final destination would more than likely require the rest of the trip to be on a truck, unless they are lucky enough to have rails right to drop point. And, in the case of the fuel boosters, the tunnel might need to be taller, unless the tanks were eliptical.

 

[jwilliams3]

I think 4' 8. 5" system works great. Suprisingly after all this time it has kept up with the demand of the modern rail system. Perfectly sized for the contemporary cargo such as roadrailer and intermodal traffic.

 

[Vaughn MacKenzie]

What's cool is RR equipment from over 100 years ago that is set for or built to standard gauge runs perfectly on today's tracks. In the mid 1960s a restored locomotive that was built in 1855 pulled two vintage rail cars all over the eastern US, traveling on several different railroads and racking up approximately 15,000 miles.

 

[rbattelle]

I guess I'm a hopeless romantic when it comes to "bigger is better".

You guys are all right about the additional problems associated with wider gauge. I hadn't really considered the additional cost of the ties.

It is true, however, that Brunel's 7' gauge Great Western Railway was one of the finest ever built in terms of load capacity (for its day) and smoothness. And the trains were fast (for their day).

Ryan

 

[Royk]

In the end, Stevenson's gauge won simply on the basis of existing trackage. The 7' gauge seems to have been better - bigger locomotives (more power), smoother running, more stability.



Imagine how much less cramped passenger trains would be at 7'. Imagine how much more power could be achieved (an end to multiple-locomotive consists?).

As to the first part of the quote; You would need "bigger locomotives (more power)" to pull the bigger heavier train cars, would you not? Moot point. Smoother running is a function of track quality, not gauge, as far as I can see. More stability is questionable. Had the railroads stuck with broad gauge back in the day, when there was no premium on space, don't you think they would have made the "overhang" of the cars basically the same ratio of track width to car width as it is now? Thus it would again be a moot point.



As to the second part; Much of this goes back to my first part argument. According to a quick google search, today’s average car width is 10' wide, more than twice the gauge. With a 7' gauge, what makes you think the railroads would not have gone to the same proportions and made the cars 14' or more wide? True it would have been less cramped, but there goes the argument for stability. Remember, this is back in the beginning days. Have you ever seen any narrow gauge equipment (3' or less)? Narrow gauge equipment made towards the end of the narrow gauge days in the USA was pretty much standard gauge rolling stock on 3 foot gauge track. Moral of the story: Corporate types will eke out the most bang for the buck that they can.



An "end to multiple-locomotive consists?" Once again we go back to my first paragraph. If the trains are 30% wider, they are proportionately more heavy. Thus you need larger locos. If for example, theoretically one standard gauge loco can pull 10 standard gauge cars, wouldn't it stand to reason that one broad gauge loco would also only be able to pull 10 broad gauge cars?



I read an interesting story a few months ago. It was how one of the largest railroads of its day, the Erie Railroad, had been a staunch supporter, and user, of 6' gauge for a long time. They then literally overnight, regauged to standard.





Roy

 

[rbattelle]

If for example, theoretically one standard gauge loco can pull 10 standard gauge cars, wouldn't it stand to reason that one broad gauge loco would also only be able to pull 10 broad gauge cars?

I'm not sure about that. I don't believe the relationship is linear.



Even if you're right, and the ratio of locomotives to cars is a constant, you've still got a nice economy of scale going! Double the size of a railcar and you get 8 times the volume!



Container ships have proven that more volume = better economy. Why wouldn't the same apply to rail?



Ryan

 

[Royk]

I'm not sure about that. I don't believe the relationship is linear.



Even if you're right, and the ratio of locomotives to cars is a constant, you've still got a nice economy of scale going! Double the size of a railcar and you get 8 times the volume!



Container ships have proven that more volume = better economy. Why wouldn't the same apply to rail?



Ryan

You bring up some interesting points. I'm a bit daffy from lack of sleep right now but consider infrastructure. Rail and ties would have to be heavier-duty, price of real estate for right-of-way would double (thus incurring more tax as well as real estate cost), shop facilities would be larger, and tunnels and bridges don't come cheap.



If volume doubles, so does weight. If it takes four 2500 h. p. locos (10,000 h. p. ) to pull a train "x" number of tons, wouldn't it take eight 2500 h. p. locos (20,000 h. p. ) to pull a train "2x" tons? True, the locos would be twice as wide, but does that mean the additional width would provide to double the horsepower?



Roy

 

[TowPro]

What's cool is RR equipment from over 100 years ago that is set for or built to standard gauge runs perfectly on today's tracks. In the mid 1960s a restored locomotive that was built in 1855 pulled two vintage rail cars all over the eastern US, traveling on several different railroads and racking up approximately 15,000 miles.

I ride some of those eastern US rails every day. I ride on Septa, which uses tracks now owned by Amtrak, on a route between Philadelphia and Harrisburg. I think the section I ride was originally installed by Philadelphia and Columbia railroad in 1834.

Anyway, some of those track sections feel like the original tracks installed over 150 years ago! The oldest markings I have seen on the actual rails is 195X cast/welded into the sides of them, short sections on wood ties. They alternate the splices, and the rails “dip” at the splices so when you go down them the car just bounces back and forth. Some sections will even wake you up if your sleeping.