Struggling to get back into work this week, here’s a nice guest post from our good friend Warren S
I first read this in Rotary’s monthly magazine some years ago and thought it may be of holiday interest while we brace ourselves for the more important business of getting Aucklanders and the government favouring the early construction of the City Rail Link.
In the United States, the standard railroad gauge (distance between the rails) is 4 feet, 8.5 inches. That is an exceedingly odd number. Why was that gauge used? Because that’s the way they built them in England, and U.S. railroads were built by English expatriates.
Why did the English build them that way?
Because the first railway lines were built by the same people who built the pre–railway tramways, and that is the gauge they used.
Why did they use that gauge?
Because the people who built the tramways used the same jigs and tools that they used for building wagons, which used that wheel spacing.
So why did the wagons have that particularly odd spacing?
Well, if they tried to use any other spacing, the wagon wheels would break on some of the old, long distance roads in England, because that was the spacing of the wheel ruts. So who built those old rutted roads?
The first long distance roads in Europe (and England) were built by Imperial Rome for their legions. The roads have been used ever since.
And the ruts in the roads?
The ruts in the roads, which everyone had to match for fear of destroying their wagon wheels, were first formed by Roman war chariots. Since the chariots were made for (or by) Imperial Rome, they were all alike in the matter of wheel spacing.
The U.S. standard railroad gauge of 4 feet 8.5 inches derives from the original specification for an Imperial Roman war chariot. So next time you are handed a specification and wonder what horse’s ass came up with it you may be exactly right, because Imperial Roman war chariots were made just wide enough to accommodate the back end of two war horses.
Thus we have the answer to the original question.
Now for the twist to the story.
When we see a space shuttle sitting on its launching pad, there are two booster rockets attached to the side of the main fuel tank. These are solid rocket boosters, or SRB’s. The SRB’s are made by Thiokol at their factory in Utah.
The engineers who designed the SRB’s might have preferred to make them a bit fatter, but the SRB’s had to be shipped by train to the launch site. The railroad line from the factory had to run through a tunnel in the mountains. The tunnel is slightly wider than the railroad track and the railroad track is about as wide as two horses’ rumps.
So, a major 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 rump!
And as you can see engineering must always be subordinate to the best practicality!
[editor’s note: While the story is not entirely true, it’s not entirely false either. There’s a good run down of it here.]
Why is New Zealand not standard gauge?
Private enterprise and the Provincial governments were the initiators of railway in New Zealand but could not really command the capital necessary for extensive construction and in 1867 were forbidden by the Central Government to raise loans independently for railways and other public works. The European population at the time was only a quarter of a million and widely dispersed throughout the country. As a result of this capital raising restriction we avoided the multi-gauge Australian situation with its high cost trans- shipment problem at break-of-gauge stations.
And then in 1870 along came Julius Vogel who borrowed 10,000,000 pounds for railway construction and because of a hilly terrain the government settled on the 3 feet 6 inch gauge. These lines were built as cheaply as possible to facilitate settlement and development of land. They were expected to produce revenue quickly. High operating costs, low speeds and inconvenience in operation were secondary and accepted as necessary evils.
So, this is what we have and while standard gauge would be more desirable in the modern age it is not an impediment to an efficient metro system.
[editor’s note: I think that last point is extremely important. We often see comments on other sites that say we should have changed to standard gauge but for running a commuter/metro network it makes little difference. For example most of the Toyko Metro is run on the same gauge we use and that hasn’t stopped it from being one of the most used metro networks in the world.]
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Urban myth!
The wagons in Wales must have been narrow gauge!
The gauge was 5′ when the flanges were outside the rails and became standard gauge when moved to teh inside.
Yes it is a myth, not least because there are all sorts of track gauges in the early days of railway, and that loading gauge (the width, height and shape of the trains themselves) are different again depending upon where you are, even across systems with the same track gauge.
As the Snopes article says, the idea that most land vehicles are all roughly the same sorts of width isn’t particularly spectacular.
As for our narrow gauge, I believe the decision was made because it allows for tighter curvature which was important in our hilly terrain. Same decision was made in Japan and various other places.
Fun story though.
While its true that large sections of the commuter rail network in the greater Tokyo area (the lines of JR, Tokyu, Seibu and Tobu rail companies and subway operators Tokyo Metro and Toei) are linked by the use of 3ft 6 gauge track, standard gauge track links several other key parts of the rail network together – Keikyu and Keisei networks, allowing trains to run between Tokyo’s two airports – Haneda in the south and Narita in the north-east. Standard gauge is also used on several major subway lines – Ginza, Marunouchi and Oedo Lines.
Apart from Shinkansen lines, a lot of Japan’s countrywide rail network is 3ft 6, principally because of the mountainous terrain.
We didn’t completely avoid break-of-gauge issues: the original Canterbury railways were Irish 5′ 3″ gauge, converted over time to 3′ 6″, with breaks of gauge along both what are now the Main North and Main South Lines – and Auckland’s first railway was standard gauge (as were NZ tramways, with the very odd exception of Wellington)..
What’s probably more important track gauge is structure (or loading) gauge – while the two are related, a standard-gauge London tube train and a standard-gauge Eurotunnel shuttle or double-stack container train make an interesting comparison.
As further evidence, most of Auckland’s passenger fleet was built for standard gauge, and Gatwick Express Mark 2s also ended up operating in Ireland on a gauge 50% wider than those running here.
Yes all our tunnels have been an issue with the narrow loading gauge. Have had to be continually lowered or daylighted to to cope with the first diesels, larger wagons and taller containers. Last 10 years most bottlenecks were removed, only ones left are on the Northland line, including one longish tunnel built in very poor soils which is a main impediment to allow 9ft 6 containers on the Northland line.
Interestingly enough UK suffers from the same restrictions, with 9ft 6 containers still now allowed on some key lines.
Wellington’s tramways used 4 ft gauge because it permitted tighter curves through the narrow streets
Alphatron: I’d be interested in your source for that information: standard-gauge tramways elsewhere had very tight curves, and if tight curves were an issue it seems odd that on electrification the gauge was widened from the NZ main-line standard of 3’6″.
The narrow gauge is probably helped make it much easier to build the Johnsonville line (which was then not a terminus) and the Raurimu Spiral….
No issue with 3′ 6″ as is Brisbane, Perth and South African Suburban lines (cape gauge). Someone once tried to tell me that spending money on the Auckland suburban system was a waste of money as our gauge was to narrow – sigh!
with regards to speed Queensland run 160kmh on their 3’6″ track, and for weight South Africa run huge Iron Ore trains nearly 4km long, 30 tonne axle loads and 47 million tonnes a year.
And as mentioned above the commuter networks of Tokyo are one of the busiest in the world on 3’6″.
I believe Tokyo’s commuter rail network is now the busiest in the world with over 2.5 million passengers a day passing through Shinjuku station alone.
Mostly a matter of finance and how quickly it needed to be built, in Central Europe e.g. they built before and during WW1 very narrow track gauge of 700mm, as those were comparatively cheap to build
It seems that the prime reason NZ has 1067 mm gauge is that it was fashionable at the time plans were being made:
http://www.jrtr.net/jrtr31/f33_sai.html.
At that time the US had demonstrated that 1435 mm and 1524 mm gauge railways could be lightly built with tight curves and since then it has been demonstrated that 1067 mm track gauge is not a limitation to relatively high axle loadings, loading gauge, train speeds and train lengths.
I’ve heard that a reason NZ has narrower gauge than Australia, is that we bought our narrow gauge system off the state of Victoria, as they wanted to standardize on a wider gauge (different states in Oz had originally installed different gauge rails, and obviously that wasn’t going to work when they crossed state borders), and we wanted a cheap secondhand railway that would be good at laying through hilly country.
I find it a little hard to believe that they physically would have uplifted rails and sleepers and shipped those across the Tasman, as surely it would be easier to just move one rail over – but perhaps the rail cross section profile is different too? Can anyone shed any truth on this, or is it completely incorrect?
MFD – I’m not sure that I’d take too seriously an article that says “Early steam engines were huge” (no way!), or “Until the mid-1850s, a railway builder could only choose between standard gauge and broad gauge”, given the plethora of gauges in Europe, the UK and the USA at the time.
One thing not mentioned is that Edmund Morel, the father of Japanese railways, had worked on railways in NZ, and it’s likely that his NZ experience helped determine Japan’s adoption of 3’6″ as its standard gauge.
I don’t take much that I read on the interweb seriously. The main point is that the choice of NZ’s gauge was less for technical reasons and more a case of what was the fad of the time or personal preference. The oft-quoted theory that 1067 mm gauge permits smaller radius curves just doesn’t stand up to scrutiny. The minimum curve radius is largely a function of design speed and rolling stock wheelbase considerations. The US adopted all bogie rolling stock early (and hence short rigid wheelbases) and as a result was able to demonstrate tight curvature, particularly on industrial sidings. The ubiquitous “American” (4-4-0) locomotive type also had a short rigid wheelbase and was tolerant of poor quality track. Had NZ adopted 1435 mm gauge but with a rolling stock designs typical of US narrow gauge operations (eg loading gauge) it is doubtful that construction costs would have been any greater. My reading on the subject suggests that in NZ there was considerable opposition to American railway influence and purchases from Anglophiles in the early days in spite of clear technical superiority in some areas. It crept in over time.
Min. track radius is very much a function of track gauge. Since the axle is solid the outer wheel must travel further than the inner when negotiating a curve. That variance is accommodated and limited by the clearance of the inner rail edge to the wheel-flange and the coning of the running surface of the wheel at 1:20. Working outside these parameters causes the screeching one hears when negotiating curves tighter than the design limit and that screeching alse represents rail and wheel wear as one wheel alternately grips then slips at high frequency. The differential motional is directly proportional to track gauge therefore at 3’6″ gauge the vehicle can negotiate a radius 25% tighter than at 4’8.5″ before this limiting state is reached assuming standard track geometry is maintained.
“These lines were built as cheaply as possible to facilitate settlement and development of land. They were expected to produce revenue quickly. High operating costs, low speeds and inconvenience in operation were secondary and accepted as necessary evils.”
Looks like Julius set transportation policy for a long time to come….
Incorrect…and it starts with the premise that the gauge in NZ is less than that in Australia. Australia still has 3 different gauges in widespread use and one of those (used extensively in QLD, WA and TAS) is 1067 mm which is what is used in NZ. VIC standardised on Irish broad gauge. The person responsible for the decision was Irish.
Amazing a little knowledge is certainly a dangerous thing especially amongst the uneducated!