3105: Interoperability

Interoperability

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Title text: We're getting a lot of complaints from commuters who were routed onto a coaster, but the theme park patrons who spent hours stuck on an intercity line are also not happy.

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Explanation

This is one of 52 incomplete explanations: This page was created by a LOST ROLLER COASTER RIDER. Don't remove this notice too soon. If you can fix this issue, edit the page!

Black Hat gives a presentation regarding the existence of two standards: rail systems predominantly use the standard gauge of 143.5cm (or the virtually identical 4 ft 8½ in, in the US), and associated subway systems and their cars are built to match this standard. Meanwhile 'many' roller coaster tracks, and their cars, are said to use a 110cm gauge. The two standards are not compatible, without some additional engineering; subway cars could not travel on roller coaster tracks, and vice versa, even assuming you solved other issues.

However, Black Hat has professed to make changes to roller coasters such that they now conform to the subway standard (i.e. 143.5cm gauge). This seemingly is Phase One of a plan, for which there is a further phase to come. No details of Phase Two are forthcoming. But, at face value, it may superficially allow subway cars to ride on roller coaster tracks and/or roller coaster cars to ride through subway systems, apparently in the name of interoperability and compatibility. Black Hat's plans to quietly connect the two, leading to various unexpected surprises.

Cueball and Hairbun are the apparently unwitting audience to Black Hat's presentation, and one of them (from off-panel) objects by stating that interoperability isn't necessarily a good thing, recognising where the plan is heading. Black Hat suggests that it would be fine as long as passengers of such interoperable systems listened to the destination announcement, which certainly confirms the above speculative continuation of the plan.

The title text confirms that both reapplications of railcars are being used. There are commuters who find themselves traveling upon a coaster; their exact problems are not stated, but they could range from merely not reaching their intended destination to suffering unexpectedly extreme g-force, if not both simultaneously.

Furthermore, those expecting to experience a theme park ride were probably expecting exciting g-forces, and also to shortly return to no more than a short walk away from where they initially boarded, but find themselves outside the theme park, spending hours on an intercity line and not moving much at all. (Noting that a subway line would also not usually be expected to travel between cities, unless serving a conurbation, but at least the interoperability of subway rail and wider rail systems might be expected, so long as the appropriate infrastructure and track links can be made compatible.) Some part of this might be that the roller coaster cars will come to a stop (in the case of gravity coasters, where the cars aren't self-propelled), which may lead to the patrons being unable to leave the cars safely and will lead to the blockage of the route.

Transcript

This is one of 27 incomplete transcripts: Don't remove this notice too soon. If you can fix this issue, edit the page!

[A close-up shot of Black Hat from the shoulders up]

Black Hat: Compatibility and interoperability are so important.

[A zoom out reveals that Black Hat is standing in front of and pointing at a diagram showing a commuter subway car and a roller coaster car, and the tracks they both run on. Standing next to him are Cueball and Hairbun]

Black Hat: For example, most subway rails are 143.5 cm apart. But many roller coasters use a narrower 110 cm gauge.

[This panel shows only Black Hat]

Black Hat: For the last few years, our company has been quietly retrofitting roller coasters to use 143.5 cm tracks.

[Black Hat now has his fists raised]

Black Hat: Soon, we can begin phase 2.

Voice from off-panel: Maybe interoperability is actually bad.

Black Hat: If you listen to the destination announcement while boarding, you'll be fine.

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Discussion

Well, it is not interoperability that would be the potential problem, but potential interconnectedness. Some systems are just not meant to be connected to the rest of the network 87.55.169.172 (talk) (please sign your comments with ~~~~) 21:48, 20 June 2025 (UTC)

Black Hat isn't in a "just not meant to be" kind of mood. Kev (talk) 23:03, 22 June 2025 (UTC)

There will be more interoperability concerns than the track gauge. Such as the up stop wheels. And side wheels. Henke37 (talk) 21:55, 20 June 2025 (UTC)

> "two standards: US rail systems predominantly have a 143.5cm gauge" Why cite "US"? 4 ft 8+1⁄2 in was developed in England. The US got confused and Abe Lincoln is credited with ordering first 5' (won't work) then 4 ft 8+1⁄2 in (most US rails were so close to 4'8.5" that they mostly changed in a weekend). Rest of world used UK or US machines, or copied them, with the main exceptions fading away over a century. (Well, Australia was still jacking cars mid-route when I was young.) https://en.wikipedia.org/wiki/Track_gauge#%22Standard%22_gauge_appears The width of two horses' asses, a Roman chariot, is often cited as if pre-industrial mechanics standardized. --PRR (talk) 05:39, 21 June 2025 (UTC)

I 'cited' the US, for simplicity. Being British, yes (like many things) it was invented/established here, but Randall typically goes by US expectations of rail-gauge (actually 143.51cm, due to being still exactly US Customary Units-based, whilst the UK is sufficiently metricised). There'll be readers in non-trivially large parts of the world where the comic mismatches their local standards, and rather than go into the whole Stephenson-and-onwards thing (noting that Brunel had a point about wider being better for at least some reasons!), I'd just "americanize" it directly. It was a direct replacement for some "(in this instance)" insertions that sort of implied that track gauges could be different from those mentioned, but seemed neither to explain the worldwide variation nor account for pretty much all railway(/railroad) track in the US, especially 'subway' systems, definitely was this (give or take a tenth of a millimetre).

Though I spent some time rephrasing things (for example, mentioning the US Customary thing, then removing it because – again — basing it on Randall's own directly cited value of exactly 1435mm (but in cm) seemed more in the spirit of things). Possibly I didn't neaten it down as much as I might, had I not tried to shoehorn those later-removed snippets in.

Had also thought to provide links to the roller coaster gauge (also presumed to be "those RCs that Randall considers standard", but had a hard time tracking anything down. I actually found many places with a different quoted track-width. (e.g. 120cm, unless that was maybe outside-to-outside vs. 110cm inside-to-inside, with the perfectly valid possibility of the coaster-rails being each 50mm tubing, and thus actually is the same? More research needed!) Closest I could find was something about "woodie / <some germanic name I forget>" systems being 110cm, in a search-engine summary of a reddit article, with a partial URL given (as part of that SE-Summary, cut off with ellipses). But visiting that reddit, I couldn't find the original full text, and I got a browser warning on trying to go to the base 'quoted' URI (long-expired and now cybersquatted by a dodgy page-redirection thing?), so eventually gave up on that and concentrated on other little changes/restructurings that I felt improved the article flow (rightly or wrongly).

Anyway, that is a boiled down why-and-wherefore of how it ended up said the way it was said (probably been re-edited, by the time you read this). Far too much background material to add to the article, I think, or even try to shove in Trivia (except maybe the 4'8.5"==1435.1mm thing?), but might interest the true connoisseur of such thought processes and tangential information who reads this bit... ;) 82.132.216.63 08:52, 21 June 2025 (UTC)

...I tweaked it myself (on top of the intermediate edit that I won't argue with). Not sure I'd have used the word "predominantly" for 'only' 55% of global track, if writing it fresh this morning. Definitely predominant for the US, though. Considered "mostly", etc, of course... 82.132.216.63 09:17, 21 June 2025 (UTC)

You likely know 0.1mm's tiny by standard gauge standards though right? Especially for subways I don't know if you'd notice at 10,326kph like that rocket sled. How fast would you have to go on 1435.1 track in a train designed for 1435 or vice versa before you'd notice? 2600:387:15:4B36:0:0:0:8 01:55, 22 June 2025 (UTC)

I do know that it's a tiny difference, and probably largely irrelevent, being a matter of a tad below 741 parts per million. But the US standard is an exact 'imperial'/US Customary measurement (before whatever 'allowable tolerances' are considered), and the non-US version of 'the same' standard is a similarly exact but subtly different metric standard. There are people who either care about these sorts of things, or could raise valid concerns if their future questions about the discrepancies aren't pre-empted. 92.23.2.228 17:09, 22 June 2025 (UTC)

As a coaster and rail nerd, it's basically impossible to actually do this (and not just for the obvious safety problems). The engineering between a rail line and a coaster track (and the wheels that run on them) are completely different. Rails have an I-beam shaped cross section and are fixed to the ground, and trains use steel wheels that have flanges on the inner side keeping the cars from running off the track. Steel roller coaster tracks have a circular cross section and the cars have wheels that are (usually) polyurethane, with additional sets of wheels on the side and running under the track (upstop wheels) keeping them from flying off when pulling Gs. Even if you corrected for any track spacing and shape difference somehow, a roller coaster train would immediately slam its upstop wheels into the ground and stop if you tried to transfer it onto a regular grounded rail line. Likewise, since roller coasters don't have flanges, they often have support beams crossing the inner space between the rails, so a train trying to navigate a coaster track would slam its flanges into the support beams and either immediately derail or else start shearing the entire track apart, if it didn't already derail from the wheel flanges not having any grip on the circular coaster rails. Optimore (talk) 07:07, 21 June 2025 (UTC)

Resolving such issues would be part of Phase 2. --81.96.108.67 07:32, 21 June 2025 (UTC)

I'm looking forward to Phase 3, where the passengers who got on a subway car, then travelled from a Metro station to a roller coaster to an intercity line get to go into a railgun. Kev (talk) 22:57, 22 June 2025 (UTC)

Why does the explanation repeatedly and pointedly mention "subway systems" when the comic doesn't mention subways at all (but rather intercity train lines)? Sophon (talk) 01:15, 22 June 2025 (UTC)

Panel 2: "For example, most subway rails are 143.5 cm apart." Are you using a different definition of "at all"? Intercity lines are only mentioned in the title text. --Coconut Galaxy (talk) 11:28, 22 June 2025 (UTC)

Randall's Late :(--Darth Vader (talk) 06:45, 24 June 2025 (UTC)

Yes a lot late. Long time since that happened when not in relation to April Fools Day. --Kynde (talk) 07:23, 24 June 2025 (UTC)

It's well into Tuesday morning Eastern and still no comic! I hope he's OK. Barmar (talk) 12:47, 24 June 2025 (UTC)

It’s currently 10:00 AM in EST, and there’s no new comic. Something’s wrong here. Any theories on why he hasn’t uploaded yet?AH24Ammit (talk) 14:03, 24 June 2025 (UTC)

Don't worry, even if that were the case we wouldn't know:

Thanks to new revisions to my site and work by Derek, I now have automated posting -- if I go missing for a few weeks, as long as I've got enough comics in the queue no one will notice

—LiveJournal#Comics only posted on xkcd.com

--FaviFake (talk) 12:58, 24 June 2025 (UTC)

”Don’t worry”?? He’s effectively saying he could by now have been missing for weeks! Jacobus-nl (talk) 16:51, 24 June 2025 (UTC)

He got on one of the retrofitted roller coasters and died because he didn't wear a seatbelt. Rest in peace. 2601:647:8500:1E09:C94A:11D6:D03D:8E55 21:13, 24 June 2025 (UTC)

8PM EDT, and no comic. I'm thinking of asking for my money back. -- Dtgriscom (talk) 00:07, 25 June 2025 (UTC)

Will it break Garden's record or is there a longer break on xkcd that Randall took? TomtheBuilder (talk) 00:58, 25 June 2025 (UTC)

Longest break THATS NOT APRIL FOOLS?--me, hi (talk) 02:06, 25 June 2025 (UTC)

The next comic finally showed up at 10:56 PM EDT, June 24. Do we want to add a "comics that were late" category? (Seems ungrateful...) -- Dtgriscom (talk) 09:34, 25 June 2025 (UTC)

Should this comics trivia section be moved to the next comic (the one that was actually late)? --Darth Vader (talk) 14:19, 25 June 2025 (UTC)

Obviously it couldn't (without maybe confusing things) appear there before it had a comic page to be generated. Yes, ultimately it might be worth transplanting the note over, but knowing about the Wednesday release (potentially some time after midnight Wed/Thu), perhaps even waiting until the Friday appears (could be Saturday early-AM) might be useful before we go too far into definitive statement/fan-guess territory. As is knowing whether Randall might be visiting some remote territory that severely skews his already flexible sense of timing, as well as keeps him away from a handy internet connection during the normally expected upload periods... ;) 82.132.244.34 16:04, 25 June 2025 (UTC)
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