By Jessica Saia

Observant frequenters of MUNI trains may have noticed a large, bolted down box of what looks like sand underneath the sideways-facing seats. The front has a gauge indicating how full the compartment is at all times, so while we know it’s “gauge-level” important, what is it for?

Everyone knows that MUNI operators share a deep, childhood-rooted love of sand; what you might not know is that their union quietly negotiated a mandatory 22-minute “sand playing” break for every six hours of work back in 2011. Each driver turns on the “SORRY, NO PASSENGERS” sign and just goes to town with their provided shovels and buckets about halfway through their shift. Inevitable moments of getting lost in the sheer joy are responsible for 38% of all train delays.

Ah, I’m kidding, and the reality is way less dreamy.

The sand is used to help the trains brake on steep hills, or after rainy weather when the tracks get slippery. It is dumped ahead of the wheels to give extra traction so that the driver doesn’t overshoot the stop. Sand is used in this fashion on SF’s cable cars, F-line streetcars, and the larger N-line style trains. Check the tracks at any downhill stop and you’ll find piles of it in the street. I know, because I live right by the N tracks near Church and Market and find that the piles of sand add a fun, additional layer of cyclist danger to the absolute clusterfuck that is the Duboce and Steiner intersection.

The more you know!

Photo by Russ Davis, who emailed us with this burning sand-question.