There are many disasters that happen all too often in today’s world. The great molasses flood was one for the ages. This unique disaster happened at a time when construction regulation was lax or non existent. Today we are going to talk about how a sticky situation quickly grew dire for hundreds of people in Boston. 



The date was January 15, 1919. It was a mild winter day for Boston. The thermometer hovered around 40 degrees Fahrenheit and there was no snow around. Boston’s North End neighborhood was a picture of activity. The neighborhood was close to the docks so it became a sort of industrial center in the town. It was here that a company known as US Industrial Alcohol had a massive steel tank designed to hold 2,500,000 gallons of molasses. They were able to ferment that molasses and quickly turn it into alcohol that was used in the war effort to make dynamite and other explosives.



Around 12:30pm workers began taking their lunch breaks when the ground began to rumble. The next several hours brought chaos to the area as people tried to make sense of what had just happened. Before we talk about the flood of molasses, I want to talk about this steel tank.



The Great Molasses Flood: Tank Failure



This disaster happened at a time when it was notoriously difficult to hold a business accountable for their mistakes. The U>S. Industrial Alcohol Co. cut corners in how they constructed this tank. The tank was not designed to hold that much molasses. 



Growing up I was an amateur aquarium enthusiast. As my fish tanks increased in size, the thickness of the glass or plastic also increased. It is basic engineering. The steel tank that U.S. Industrial Alcohol Co. built to store their molasses was designed to hold 2.5 million gallons of molasses. It was 50 feet tall and about 90 feet in diameter. The steel walls ranged in thickness from .31 inches to .67 inches. These were far too thin to support the weight of a full tank of molasses. 



USIA also cut corners in other areas. They didn’t do full testing for flaws and imperfections. Simply filling the tank with water first would have revealed several flaws with the tank. In addition to the thin walls, they had a rivet design that leaked. The first cracks in the tank originated from these rivets. 



Leaky Rivets and Brittle Steel



It was a known fact that this tank leaked. Kids showed up to the site with cups to gather molasses that was leaking from the tank. Molasses was poured into the tank 29 times before the tank failed. Only four of those filled the tank to capacity. The fourth time the tank was filled to capacity happened two days before the catastrophe. 



The raw steel used to construct this tank had fundamental flaws. It had been mixed with too little manganese. This meant that the steel would get brittle when it cooled below 59 degrees Fahrenheit. As I mentioned previously, the temperature the day of the disaster was 40 degrees. A perfect storm had been put in place. A tank that was not designed and properly engineered to hold this amount of liquid. To recap, metal is brittle, tank is full, and it is a busy time of day. The stage was set for what was to come next. 



Rapid Emergency Response



Growing up I moved slow. I’m sure for my parents it was maddeningly slow. On more than one occasion my mom said that I was moving about as fast as molasses in January. After this episode, I’m going to view that as a compliment. 



Molasses is not like water. If you tip over a bottle of molasses, it takes a second for the syrup to come out. If the molasses is cold, it moves even slower. However,