The Great Molasses Flood

Fluid Dynamics

The Great Molasses Flood was a catastrophic event influenced by the unique properties of molasses. Gary Arndt explains that molasses is a shear thinning fluid, meaning it becomes less viscous under pressure, allowing it to flow more easily. This property, combined with the heat from a recent shipment, significantly reduced its viscosity, contributing to the disaster 1.

Molasses is a non-newtonian fluid. It does change its viscosity based on the stress applied.

--- Gary Arndt

Once the tank burst, the molasses flowed rapidly like water, but as it spread and pressure decreased, it thickened again, trapping people and causing devastation 2.

   

Weather Impact

Environmental conditions played a crucial role in the Great Molasses Flood. A sudden warm front in Boston caused temperatures to rise dramatically, leading to thermal expansion of the molasses within the tank 1. This, combined with the addition of warm molasses from a ship, increased the pressure inside the tank to catastrophic levels.

The temperatures went from two degrees Fahrenheit to 40 degrees Fahrenheit in one day.

--- Gary Arndt

The resulting explosion released a massive wave of molasses, which traveled at 35 mph, causing widespread destruction and loss of life 1.