This memo is a failure analysis report on the Boston Molasses Disaster. On January 15, 1919, an industrial storage tank ruptured, causing 9 million litres of molasses to spill out onto the streets of Boston. The following sections of this report document the events leading up to and during the disaster, the causes that led to the failure, and the lessons that can be learned as a result.
2. Description
The tank in question was owned by United States Industrial Alcohol Company (USIA) and located at 529 Commercial Street in Boston’s densely populated North End (see Figure 1) (Dyrud, 2009, para. 12).
Only two days after the completion of the tank, 700 000 gallons of molasses were deposited into the tank. Loud rumblings sounds and leaks were immediately observed. Many complaints were made to the company, but they were categorically ignored. In 1918, however, they had the previously …show more content…
Causes of the Failure
The tank stood 15 m tall, 27 m in diameter on a cement foundation on top of concrete stacks. It consisted of “overlapping steel plates stacked into seven overlapping rings”, and was secured with rivets. After the explosion, MIT Professor C.M. Spofford, in a report to the City of Boston, observed that the plates weren’t thick enough to meet safety standards. Furthermore, he stated that not enough rivets were used, and as a result, the sides of the tank could only withstand 18 000 psi of stress. On January 15, it was subjected to over 31 000 psi. Additionally, the unexpected rise in temperature that winter day (-15.5°C two days before to 4.4°C) caused the molasses to expand and increase the internal pressure. Consequently, the tank became overstressed and gave way, launching rivets and plates in all directions (Puleo, 2001, p. 63).
On another level, the failure was also the result of a profound lack of engineering expertise during the construction of the tank, lack of safety protocols taken, and ignorant greed from the company.
3. Lessons to be