Solving a Mystery: Behind the Deadly ‘Tsunami of Molasses’ of 1919
A tank containing millions of gallons of molasses erupted in Boston in January 1919, killing 21 people and destroying buildings in the North End. Credit Associated Press
“A dull muffled roar gave but an instant’s warning before the top of the tank was blown into the air,” The New York Times wrote in 1919. “Two million gallons of molasses rushed over the streets and converted into a sticky mass the wreckage of several small buildings which had been smashed by the force of the explosion.”
“Wagons, carts, and motor trucks were overturned. A number of horses were killed. The street was strewn with debris intermixed with molasses and all traffic was stopped.”
It was January. The place was Boston. And when 2.3 million gallons of molasses burst from a gigantic holding tank in the city’s North End, 21 people were killed and about 150 more were left injured. The wave of syrup — some reports said it was up to 40 feet tall — rushed through the waterfront, destroying buildings, overturning vehicles and pushing a firehouse off its foundation.
For the past 100 years, no one really knew why the spill was so deadly.
But at a meeting of the American Physical Society this month, a team of scientists and students presented what may be a key piece of the century-old puzzle. They concluded that when a shipment of molasses newly arrived from the Caribbean met the cold winter air of Massachusetts, the conditions were ripe for a calamity to descend upon the city.
By studying the effects of cold weather on molasses, the researchers determined that the disaster was more fatal in the winter than it would have been during a warmer season. The syrup moved quickly enough to cover several blocks within seconds and thickened into a harder goo as it cooled, slowing down the wave but also hindering rescue efforts.
“It’s a ridiculous thing to imagine, a tsunami of molasses drowning the North End of Boston, but then you look at the pictures,” said Shmuel M. Rubinstein, a Harvard professor whose students investigated the disaster.
When the molasses arrived in Boston’s harbor, it was heated by just a few degrees. The warmer temperature made it less viscous and therefore easier to transport to a storage tank near the waterfront.
When the tank burst two days later, the molasses was still probably about four or five degrees Celsius warmer than the surrounding air, said Nicole Sharp, an aerospace engineer and science communications expert who advised the Harvard students. (She runs the website FYFD, through which she explains the principals of fluid dynamics to people outside academia.)
Harvard students performed experiments about how molasses would behave in cold temperatures to understand the deadly 1919 molasses spill in Boston. By ROSA BONILLA, GRACE KOSSIA AND EMILY WOOLWAY on Publish Date November 25, 2016. Photo by Rosa Bonilla, Grace Kossia, and Emily Woolway. Watch video of experiment HERE
The students performed experiments in a walk-in refrigerator to model how corn syrup, standing in for the molasses, would behave in cold temperatures. With that data in hand, they applied the results to a full-scale flood, projecting it over a map of the North End. Their results, Ms. Sharp said, generally matched the accounts from the time.
“The historical record says that the initial wave of molasses moved at 35 miles per hour,” Ms. Sharp said, “which sounds outrageously fast.”
“At the time people thought there must have been an explosion in the tank, initially, to cause the molasses to move that fast,” she added. But after the team ran the experiments, she said, it discovered that the molasses could, indeed, move at that speed.
“It’s an interesting result,” Ms. Sharp said, “and it’s something that wasn’t possible back then. Nobody had worked out those actual equations until decades after the accident.”
If the tank had burst in warmer weather, it would have “flowed farther, but also thinner,” Mr. Rubinstein said.
In the winter, however, after the initial burst — which lasted between 30 seconds and a few minutes, Ms. Sharp said — the cooler temperature of the outside air raised the viscosity of the molasses, essentially trapping people who had not been able to escape the wave.
About half the people who were killed “died basically because they were stuck,” Mr. Rubinstein said.
A firefighter who survived the initial wave managed to stay alive for nearly two hours while he waited to be rescued, they said, but he drowned.
“Men and women, their feet trapped by the sticky mass, slipped and fell and were suffocated,” The Boston Globe wrote in 1968. “The stronger tried to save others, and many of them died for their heroism.”
The exact cause of the tank’s failure has never been known. Last year, a team of engineers using modern methods to analyze the century-old disaster blamed poorly designed steel tanks.
Ronald Mayville, a structural engineer who worked on that study, told The Boston Globe that the tank’s walls were at least 50 percent too thin and were made of a type of steel that was too brittle.
The project at Harvard grew out of Mr. Rubinstein’s class Introduction to Fluid Dynamics, which asks students to create a final project. “Choose an interesting project and make an appealing video,” he said.
Mr. Rubinstein and Ms. Sharp said they would like to eventually build an entire course around the disaster, where students could apply what they learn in other classes to understanding not just why the molasses behaved the way it did, but also what other forces shaped the events of that day in 1919.
The Boston molasses disaster, Mr. Rubinstein said, is “a beautiful story for teaching.”
If you still haven't had enough, check out this book:
Dark Tide: The Great Boston Molasses Flood of 1919 by Stephen Puleo
From Publishers Weekly
In this volume, Puleo, a contributor to American History magazine, sets out to determine whether the collapse of a molasses tank that sent a tidal wave of 2.3 million gallons of the sticky liquid through Boston's North End and killed 21 people was the work of Italian anarchists or due to negligence by the tank's owner, United States Industrial Alcohol. Getting into the minds of the major players in the disaster-USIA suits, victims, witnesses, North End residents, politicians-he re-creates not only the scene but also the social, political and economic environments of the time that made the disaster more than just an industrial accident. While the collapse's aftermath is tragic, the story itself is not exactly gripping. More interesting are the tidbits of Boston's and America's history, such as the importance of molasses to all U.S. war efforts up to and including WWI, which Puleo uses to put the tank collapse in the context of a very complex time in U.S. history. The most striking aspect of this tale is the timeliness of the topics it touches on. Describing Americans being persecuted because of their ethnicity, a sagging economy boosted by war, and terrorism on U.S. soil that results in anti-immigration laws and deportations, Puleo could just as easily be writing about current events as about events in 1919.
Overall, this is another piece in the jigsaw puzzle that is Boston's long and rich history. Photos.
Copyright 2003 Reed Business Information, Inc.
Copyright 2003 Reed Business Information, Inc.
From The New Yorker
In January, 1919, a fifty-foot tank filled with molasses exploded, sending waves of viscous goo through waterfront Boston and killing twenty-one people. Were Italian anarchists to blame or was it negligence by the tank's owner, the United States Industrial Alcohol company? Such matters form the crux of Puleo's account, which is narrated with gusto (and sometimes too much gusto: one victim has molasses "clinging to his private parts, like an army of insects that just keep coming"). Molasses was a vital commodity at the time, used in rum manufacture (the tank was full to the brim to cash in on pre-Prohibition demand), and it had been important in the production of First World War munitions.
Puleo overreaches in claiming the story of the flood as a "microcosm of America"—an almost obligatory conclusion in this sort of history—but his enthusiasm for a little-known catastrophe is infectious.
Copyright © 2005 The New Yorker
You can get it on Amazon.com for a penny plus shipping.