Courtesy of Dark Tide and Boston Fire Department Archives A week later, with the almost-full tank weighing 26 million pounds and the gas inside putting extra pressure on the steel walls, it ruptured.ĭamage from the Great Boston Molasses Flood in 1919. People reported hearing the tank whining and groaning. Puleo said that seven days before the flood, on a day with a low of 2 degrees Fahrenheit, a new shipment dumped more than half a million gallons of molasses into the poorly built tank.Īs warm molasses from the ship mixed with cold molasses in the tank, it triggered a fermentation process that produced gas. In 1918, in an effort to shield the leaks and avoid costly fixes, Jell even had the steel-colored tank painted brown, to camouflage the oozing molasses. Profits from the war were pouring in as steadily as molasses was leaking out of the tank. 'It should have been very straightforward.' Building the tank, Mayville explained, is 'a relatively simple calculation that most engineers could do in that day.'Įven though workers alerted USIA to the leaks, the company remained unperturbed. 'The stress in the tank is directly linked to the fluid inside,' he said. Mayville analyzed the flood using today's engineering tools and suspects the tank might have been designed for water instead of molasses. Ronald Mayville, a senior principal at the engineering firm Simpson Gumpertz & Heger in Massachusetts, has studied the molasses flood in his spare time. 'The tank starts leaking on Day 1,' Puleo said. Instead of filling the entire tank with water after it was finished to test for leaks, he only put in six inches of water. People were trapped, with witnesses described trying to breathe while stuck, gasping for their lives and simultaneously trying to avoid inhaling too much.įrom the beginning, Jell sidestepped safety precautions. As molasses flooded the streets, it slowed but became thicker and stickier, and still difficult to escape. Many survivors had broken backs and fractured skulls.ĭuring the second stage of the flood, 'the inertia runs out as the molasses spreads - that's when viscosity starts to matter,' Sharp said, referring to a liquid's resistance to flow. People's bones were crushed, their bodies thrown onto buildings and train cars. 'When the initial wave came through, it just pulverized everything,' Sharp said. When the tank broke and the molasses exploded, there was no outrunning it. The inertia is so much more powerful than the forces that can be moved by the viscosity.' 'The fact that the molasses is extremely viscous doesn't matter for the first 60-90 seconds. When the tank ruptured, all that potential energy became kinetic energy. The tank, piled so high with molasses, stored a large amount of potential energy. 'Molasses is 1.5 times heavier than water. Sharp said the flood could be broken down into two stages, with the first called 'The Tsunami.' 'I found that the initial wave could have moved at that speed,' she said. Sharp decided to look into the science behind the flood, along with a team of scientists at Harvard.

Great boston molasses flood plaque