I’ll be the first to admit that I have a sweet tooth as devilish as the next person. But if I were to see a 25-foot tidal wave of straight molasses cascading through the narrow streets of Boston’s North End at 35 miles per hour, needless to say, I’d freak out. That was the scene on this fateful day in Boston history, 95-years ago, when The Hub was subjected to what’s been since referred to as the Great Molasses Flood.
On January 15, 1919 with weather not so dissimilar from that which we’ve experience here in Boston post-Polar Vortex – mid-40 degrees in the throes of winter – the Purity Distilling Company’s 50-foot tall molasses tank, roughly 90-feet in diameter and containing as much as 2,300,000 gallons of collapsed upon itself, spewing the thick, sugary sweetener out into The Hub.
So destructive was the molasses that, as noted by Scientific American, it “crushed freight cars, tore Engine 31 firehouse from its foundation and, when it reached an elevated railway on Atlantic Avenue, nearly lifted a train right off the tracks.”
Unfortunately the catastrophe resulted in the deaths of 21 while injuring 150. Continues Scientific American, “About half the victims were crushed by the wave or by debris or drowned in the molasses the day of the incident.” The rest perished from fatal injuries and infection within the subsequent weeks.
But how did such a tragic event occur in the first place?
The answer lies within the properties of molasses. First, though, it’s important to note that the tank itself was structurally unstable, with a number of reported leaks and inadequacies having been reported.
As for the molasses itself, due to fermentation having taken place inside the tank, which was filled nearly to the brim, a pressurized quantity of CO2 formed and, combined with the unusually warm weather atypical of January, increased the strain from within. The tank became, essentially, a ticking time bomb and eventually burst, emitting a deadly wave of thick fluid that is not only impossible to swim in – due to a significantly higher density and viscosity compared to, say, water – but settles into a gelatinous state, trapping those caught in the wake.
As for that whole “slow as molasses” bit, keep the following in mind;
A wave of molasses does not behave like a wave of water. Molasses is a non-Newtonian fluid, which means that its viscosity depends on the forces applied to it, as measured by shear rate. Consider non-Newtonian fluids such as toothpaste, ketchup and whipped cream. In a stationary bottle, these fluids are thick and goopy and do not shift much if you tilt the container this way and that. When you squeeze or smack the bottle, however, applying stress and increasing the shear rate, the fluids suddenly flow.
While today it might be fun to joke about how Boston was once submerged in a flood of molasses for weeks on end, it was a deadly occurrence and we remember those who were unfortunately lost.
But, if you happen to be in the unusual predicament where you’re being chased a 25-foot tall blob of sweet syrup, please don’t think you can outrun it.
