Floppy disks aren't dead yet as this San Francisco train line relies on three of them to run every morning

Close-Up Of Two Floppy Disks Against Yellow Background
(Image credit: Javier Zayas Photography via Getty Images)

The sound of a crunching floppy disk drive may well be the soundtrack to a large part of my misspent youth. Please insert disk four of five. Oh you've lost it? No games for you, little Andy. No games for you.

Putting my childhood trauma aside for a moment, it turns out that floppy disks may not be quite as dead as we thought. Incredibly, San Francisco's Municipal Transportation Agency is still reliant on three 5.25-inch floppies to load the software required to run the central servers for its Muni Metro light rail line each morning, which in turn controls the system that allows trains to run in automatic mode while in the subway system. (via Ars Technica). Totally reasonable, that.

The good news is, the SFMTA is attempting to update the system to remove its reliance on decades old technology. The bad news, however, is the initial planning took place in 2018, and due to some covid-related delays, it's planning on completing the project in, err, 2029-2030. 

Grand. Anyways, to the SFMTA's credit, it's been highlighting exactly why a floppy disk-based train control system is a bad idea in this modern day and age, which seems rather obvious but let's go there anyway. As Jeffery Tumlin, the director of transportation for the agency rather succinctly puts it:

"The system is currently working just fine, but we know that with each increasing year, risk of data degradation on the floppy disks increases and that at some point there will be a catastrophic failure."

And when it comes to train incidents, the term "catastrophic failure" really is enough to raise the hairs on the back of your neck. The system first came into usage in 1998 and was expected to last 20 to 25 years, meaning that it passed the upper margin of that time frame last year. The lifespan of an individual floppy disk itself is difficult to estimate, but is said to have an upper range of around 10-20 years when stored correctly, and Sony, the last diskette maker, ceased production in 2010.

Still, this wouldn't be the first time critical systems were revealed to be relying on outdated floppy disk technology in recent years. Boeing was still found to be updating at least part of its now-retired 747 fleet in 2020 with 3.5 inch floppies, while the US nuclear arsenal relied on a floppy drive-based computer system up until 2019.

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While planes in the air and nuclear weapons in…well, wherever the US is keeping them these days can both absolutely be described as critical systems capable of causing chaos in the event of a glitch, so are trains, so here's hoping that the disks can hold out until the system is eventually replaced.

In the meantime, the humble floppy continues to survive in the most unlikely of places, and in this case, seems to be clinging on to relevance for another few years at least. Some tech just refuses to die, and for that alone, I salute you, floppies. Now, where did I put that last Frogger diskette?

Andy Edser
Hardware Writer

Andy built his first gaming PC at the tender age of 12, when IDE cables were a thing and high resolution wasn't. After spending over 15 years in the production industry overseeing a variety of live and recorded projects, he started writing his own PC hardware blog for a year in the hope that people might send him things. Sometimes they did.

Now working as a hardware writer for PC Gamer, Andy can be found quietly muttering to himself and drawing diagrams with his hands in thin air. It's best to leave him to it.