An Interview With the Guy Behind That Viral Railroad-Gauge Tweet Thread

“It’s only a bit of fun at the end of the day.”

A horse's rear end and railroad tracks.
Photo illustration by Slate. Photos by Manuel-F-O/iStock/Getty Images Plus and DONGSEON_KIM/iStock/Getty Images Plus.

On Friday, a 59-year-old solicitor from Cork, Ireland, named Bill Holohan posted an 11-part thread on Twitter about the history of railway gauges, which is the distance between rails. In the thread, Holohan contends that the standard railroad gauge in the U.S.—4 feet, 8.5 inches—derives from the way that rail lines were built in England, where engineers based the width of their railroads on the spacing of road ruts in Imperial Rome, which were in turn designed to accommodate the size of horses’ rear ends. Holohan then writes that one of the first manufacturers of spaceship rocket boosters in the U.S. built them to ensure that they would fit into train tunnels, which are slightly wider than the standard rail gauge. Based on these suppositions, Holohan concludes with a pithy line: “Ancient horse’s asses control almost everything and…. CURRENT Horses Asses are controlling everything else.”

The thread went viral and currently has more that 50,000 retweets and 125,000 likes. Ryan Reynolds even retweeted it. Yet many Twitter users quickly pointed out that the some of the facts in the thread weren’t quite right, and the framing may have been misleading. As one critic wrote, “Nope, nope. This is bollox. It’s been debunked so many times.” In fact, Snopes probed this narrative back in 2001, noting that people have been telling similar tales about rail gauges since at least 1905. The fact-checking site ultimately rated the narrative as a “mixture” of true and false. Snopes concludes that it’s true that “standard U.S. railroad gauge is similar in width to the wheel spacing of Roman chariots,” but that the “similarity is based much more on coincidence and inherent physical limitations than a direct line of imitation.” The site also notes that the standardization of railway gauges in the U.S. is mostly an artifact of the Union winning the Civil War and rebuilding Southern railways to match those in the North.

I spoke to Holohan on Tuesday to get his take on the attention that his thread received and on the controversy it sparked. The interview has been condensed and edited for clarity.

Aaron Mak: I wanted to get a sense of when you made this connection between railroads and Roman chariots in the first place.

Bill Holohan: I first put out that posting on Facebook about two years ago, and nobody took any notice of it whatsoever. But it had crossed my consciousness again on Friday evening because I was traveling down from Dublin to Cork, my home. Something on the radio prompted the thought to go through my head in connection with the space rockets. I looked it up on my computer and posted it on Twitter. And for some strange reason, the thing just exploded.

What do you make of the reaction to the post?

To tell you the truth, I stopped looking at it because there’s a few thousand comments. There were people debunking the post, and then there were people debunking the debunkers. I didn’t have the time, the energy, or the inclination to get involved in following all of it. But it’s very interesting to see the reaction. Some people are getting very excited with joy, and other people are getting agitated and annoyed. If it amuses people, that’s probably the most important thing.

I mean, do you think the challenges to it are valid?

I sent you the list of the sources that I had to try and check as much as possible. [Editor’s note: Holohan sent me the links he used to check his thread. I’ve not been able to verify whether they settle any of the larger controversies conclusively.] You know, somebody posted about how the Southern states had a different way for gauges, therefore suggesting that all American railways weren’t built to the U.K. standard. Fair enough. If they feel agitated enough to post about that, that’s fine. And I’m open to correction. We all learn new things every day. And so, what the hell?

Did you have thoughts on the Snopes article that people were posting in response, which noted that similarities between Roman chariot tracks and U.S. railroad tracks were more of a result of “coincidence and inherent physical limitations?”

Well, it could be coincidence, but then, you know, such a remarkable coincidence. It could be that somebody had this in the back of their mind, forgot they had it in the back of their mind, and simply measured it out accordingly. Who knows? It’s lost in the midst the time, unless you can get a direct thing from some Roman war builder to an English train carriage–maker to whoever is setting down the first rails in the U.S. Who knows?

While we were setting up this interview you had written in an email that while you “always strive to achieve accuracy, if it amuses people, then at the end of the day that’s as much benefit as anything else.” So the point was to amuse?

Oh, absolutely. I mean I put out a posting almost every single day, and usually it’s something historical. But I always try and put a little bit of a kink in it, as opposed to simply reciting historical facts, to make it interesting or something that’s worthy of comment. Now, I didn’t expect to get that kind of reaction.

The exact historical accuracy isn’t as much of a focus, necessarily?

Well insofar as I can, or as anybody can. When the issue is history, you try to be accurate, but obviously the further back you go, the more difficult it is to get verifying sources. Now, as I say, if you want to go and measure the rocks between the tracks in Pompeii, which is probably one of the best preserved in the world, and measure them against the English railway gauge and some of the American ones, it’s coincidentally the same gauge. Is that purely coincidence? Possibly.

Why do you think people got so “agitated,” or in a frenzy, over this?

Hard to know. I’ve heard the expression “keyboard warriors”—you know, people who would vent online in a way that they might not do face to face. I don’t know why people get so agitated.
It’s only a bit of fun at the end of the day.

Have any of your other tweets gotten this much attention?

No, no, I wouldn’t expect that it’ll ever happen again. I’m not going to try and build a career based on Twitter posting.

Future Tense is a partnership of Slate, New America, and Arizona State University that examines emerging technologies, public policy, and society.