[sbuttgereit]

On the other hand....

"Unification to standard gauge on May 31 – June 1, 1886 [United States]

In 1886, the southern railroads agreed to coordinate changing gauge on all their tracks. After considerable debate and planning, most of the southern rail network was converted from 5 ft (1,524 mm) gauge to 4 ft 9 in (1,448 mm) gauge, then the standard of the Pennsylvania Railroad, over two days beginning on Monday, May 31, 1886. Over a period of 36 hours, tens of thousands of workers pulled the spikes from the west rail of all the broad gauge lines in the South, moved them 3 in (76 mm) east and spiked them back in place.[6] The new gauge was close enough that standard gauge equipment could run on it without problem. By June 1886, all major railroads in North America, an estimated 11,500 miles (18,500 km), were using approximately the same gauge. To facilitate the change, the inside spikes had been hammered into place at the new gauge in advance of the change. Rolling stock was altered to fit the new gauge at shops and rendezvous points throughout the South. The final conversion to true standard gauge took place gradually as part of routine track maintenance.[6] Now, the only broad-gauge rail tracks in the United States are on some city transit systems."

https://en.wikipedia.org/wiki/Track_gauge_in_the_United_Stat...

[PaulRobinson]

An impressive feat, that is unlikely unachievable on a modern train network.

The tolerances are just a bit tighter, the risks and liabilities are higher, and the workforce just isn't "there" - this is from a time when rail was a huge money earner and could afford to employ a huge number of people. Today? Not so much, pretty much anywhere in the World.

[Suppafly]

>The tolerances are just a bit tighter, the risks and liabilities are higher, and the workforce just isn't "there"

Sure, but they do it with big machines that ride down the rails now instead of lining up thousands of men with sledge hammers.

[crote]

There are no ready-made gauge changing machines, though. Not exactly a big market for those.

[mikewarot]

There are ready-made machines that pull up track, and replace sleepers... it shouldn't be a major project to allow it to change the gauge of the rail as it resets it.

[wkat4242]

Once Spain and Portugal move from Iberian gauge that market will increase a lot. Which is kinda inevitable with the added environmental pressure on flights.

[wyan]

It is taking decades to achieve though!

[reaperducer]

There are no ready-made gauge changing machines, though. Not exactly a big market for those.

So what? I'd there isn't a machine, you build one.

Large industries like mining and shipping and the military don't just stop because they can't buy a needed item off the shelf because there isn't a market for it. They build stuff all the time.

I worked in a factory for a few years, and can tell you that if industries followed your "can't do" attitude, commerce would stop.

[owenversteeg]

Yeah, in theory, but the vibes are different.

Let’s say you have a problem and the only way to solve it is with a thingamabob. The thingamabob doesn’t exist, so you need to make the first one. Unknown to everyone, the military, the O&G/mining industry, and the rail industries all try to build one at the same time. Do you think they all cost the same? What about the time to design and build them?

The oil and gas people will call up some machinists and engineers the same day. Time is money and they need the problem solved. It doesn’t need to look pretty. I don’t think anyone would disagree that they would be the first with a thingamabob. First one might break, they’d get Bob on a Cessna from the nearest machine shop with a replacement.

The military would have some meetings, which would spawn more meetings, and eventually put out some requests for proposals. They’d review the proposals and ten years later they’d have their thingamabob. No doubt it would be the most expensive.

The rail industry… the modern, passenger rail industry in wealthy western countries? There might be proposals, or designs or prototypes with large amounts of money spent, but I think it is reasonable to say the thingamabob would never actually be built and used. Look at CAHSR or Stuttgart 21 or Turin-Lyon.

[red_admiral]

Switzerland has some for narrow (meter) gauge to standard gauge. I think it's to make the Glacier Express run without changing train. Had a bit of teething problems at the start but seems to be working well now.

That's not a "change gauge for a 100-wagon freight train" scale operation, and it's not "off the shelf" tech, but we're fairly close I think?

[Suppafly]

>There are no ready-made gauge changing machines, though. Not exactly a big market for those.

I'm not a train guy, but I'm pretty sure the machine that lifts the track up and allows them to swap out the ties is like 95% of what would be needed for a gauge changing machine.

[hedora]

In the US, rail tolerances seem to be getting looser over time, and derailments are still uncommon.

I’d guess that overseas modern non-high speed trains could deal with it. The passengers might not put up with it though.

[sehansen]

There have been around 3 derailments per day in the US in the past few years: https://www.nlc.org/resource/interactive-rail-safety-map-see...

[fuddy]

A country that would put up with US rail is a big ask.

[panick21_]

Derailments are incredibly common in the US.

[mschuster91]

> this is from a time when rail was a huge money earner and could afford to employ a huge number of people.

Well, back then the US had freshly banned slavery, so there was an ample workforce that could be hired for dirt cheap.

The Soviets and the Wehrmacht pulled off similar feats in WW2, but back then the rails and sleepers didn't have to be built to last many decades, so in addition to loads upon loads of forced labor from concentration camps and gulags, the work effort was massively reduced because easier technology could be used.

[metadat]

Corresponding discussion:

The Days They Changed the Gauge (1966) - https://news.ycombinator.com/item?id=8371773 (2014, 15 comments)

And a related discussion:

Why BART uses a nonstandard broad gauge - https://news.ycombinator.com/item?id=32031131 (2022, 253 comments)

The BART discussion was where I first learned about the North American 2-day gauge change. A truly inspiring feat for so many engineers to come together across such a large amount of land area to Make It Happen.

[dehrmann]

Makes it even crazier that Bart would choose a non-standard gauge 75 years later. And now they're stuck paying for custom trains with less flexibility and longer lead times.

[wbl]

BART was always going to need custom trains for other reasons beyond track gauge. Electric third rail at those speeds isn't standard. 125kV pantagraph would mean big expensive tunnels and stations due to clearance requirements.

[badc0ffee]

Electric third rail at 130 km/h? The LIRR does it, with standard gauge: https://en.wikipedia.org/wiki/Long_Island_Rail_Road

I also don't know where you're getting 125kV from. Many trains throughout the world use 25kV, especially high-speed ones (actually high speed, like 200+km/h), but BART uses 1000V, which is closer to a typical subway system.

[fanf2]

Third rail lines south of London often run at 90mph and up to 100mph in places. BART’s top speed is 80mph.

[LargoLasskhyfv]

12.5kV?

[wbl]

Thank you!

[Gravityloss]

Amazing.

I wonder if one can do anything like this with the current concrete sleepers and thermite welded tracks.

[IAmBroom]

The welds could be cut and rewelded, obviously.

The sleepers are molded with preset widths, however, and would need replacement.

[close04]

Probably the biggest challenge is that there is way more rail traffic today and it's more tightly coupled in logistics chains and people's day to day lives. Disruptions are more expensive and harder to tolerate. And that's on top of the technical challenges, tolerances leave less room for error today.

[shaftoe]

(US centric assumption)

It might be easier to change today than it was in 1886. Back then, trains were really the only means of travel between cities. Today, there are less passenger trains than back then, though more freight (even with trucks and planes). But freight diversions/delays could be scheduled well in advance and have alternative means. Not to mention, since then we've developed variable gauge train tech. A subset of trains could run during the cutover.

It's likely more costly today, but less disruptive.

[MyPasswordSucks]

Passenger travel is easy mode. The economic consequences of disrupted freight dwarf anything you could imagine from disrupted passenger travel of equal duration. That's why the US has always strived to do a really, really good job with their freight rail system, and US freight is still to this day generally considered the best freight rail system in the world, even as passenger rail lags well behind.

Remember that freight is more than just moving pallets of finished goods to Amazon warehouses. It doesn't matter if you've given the cows a month's advance notice, if they don't have feed they're still going to starve; and no matter how many KPIs you dangle at the silos, they're only going to hold x amount of reserve grain.

[AlotOfReading]

Any competent shipper facing a train issue will just put the load on semis instead for 3-10x the price. Freight rail mainly exists as an low cost bulk carrier of convenience these days. Ships outcompete rail for bulk goods along inland waterways, and semis outcompete rail for network volume, ease of delivery, and adaptability to constraints.

[Reason077]

> "Today, there are less passenger trains than back then"

I don't think this is true in Europe. Certainly in the UK, passenger rail volume since the 2010s has set records higher than in any previous years, exceeding numbers that were last seen before WW2. Today there are fewer miles of track than there were in that era, but modern signalling technology allows more trains to operate safely on the same tracks, and modern trains run much faster on average.

As for freight, the US actually moves a significantly greater portion of its freight by rail than Europe does. Rail has around 40% modal share for freight in the US vs only 17% in Europe. One reason for this is that in Europe many lines are congested with passenger traffic, leaving few slots for freight trains to operate - except late at night.

[jabl]

> As for freight, the US actually moves a significantly greater portion of its freight by rail than Europe does. Rail has around 40% modal share for freight in the US vs only 17% in Europe. One reason for this is that in Europe many lines are congested with passenger traffic, leaving few slots for freight trains to operate - except late at night.

It's also that rail tends to be more competitive for long haul traffic, and the US operators have big trans-continental freight networks well suited to that. In Europe there's a sharp drop off in modal share as freight crosses borders. Each national railway operator is in practice fiercely protective of its own turf, and there are a lot of hurdles to overcome. So in practice cross-border freight is largely done with trucks instead.

Despite the EU commission wanting to get some competition going on the rails and better interoperability requirements etc etc. for at least the past 30 years, the operators are still in the "discussion about preparing to setup a committee to discuss interoperability" phase.

[crote]

> As for freight, the US actually moves a significantly greater portion of its freight by rail than Europe does. Rail has around 40% modal share for freight in the US vs only 17% in Europe.

Europe also has far more freight-friendly waterways. US rail is designed for dirt-cheap bulk transport for things like coal and grain. In most of Europe that's done by barge - but US geography doesn't really allow for that.

[Gravityloss]

Since it's only 90 mm, I wonder if one could add some sort of a 45 mm lateral adapter between the rails and the ties on both sides. At least for low speed track parts...

[Cthulhu_]

Probably not, but laying track or replacing sleepers is a very satisfying to look at, fully automated process.

[phkahler]

Imagine one short "train" whose tail is able to pull up one rail of the track behind it. Then another train whose front is an automated thingamajig to take the loose rail and nail it down a specific distance from the fixed rail. How much play there is in the loose rail depends on how far apart these two train are. Notice that the nailer runs on the narrow rails while the nail-puller runs on the wide ones.

[gosub100]

Even the wooden sleepers would have to be weakened by moving the spikes over. Unless the old holes were patched.

[nayuki]

> Now, the only broad-gauge rail tracks in the United States are on some city transit systems.

One such oddball is the TTC subway/streetcar gauge of 1495 mm in Toronto, Canada. https://en.wikipedia.org/wiki/Toronto-gauge_railways

[earnestinger]

Does it imply that, Toronto finally is one of United States cities with broad gauge rail tracks?

[noelrock]

So odd - was listening to an account of this in an Audiobook just yesterday - "Why Nothing Works" by Marc Dunkelman. Was essentially making the point that this sort of thing would be several magnitudes of difficulty harder to pull off today, and certainly wouldn't happen within that timeframe.