Flooded in history
BOSTON — Almost 100 years later a nagging question remains how did the Great Molasses Flood happen?
A group of about 20 people taking part in the Whitman Reads project centering on Stephen Puleo’s book, “Dark Tide: The Great Molasses Flood of 1919,” travelled to Boston Friday, April 24 to hear a presentation on the latest theory and visit the site of the disaster. The community reading program concludes tonight with a second visit by Puleo at 6 p.m., in the Whitman Library.
Ronald Mayville, a senior structural and metallurgical engineer with the Waltham firm of Simpson, Gumperts & Heger, outlined his research — which is pointing to metal stress on a low-manganese type of steel used in the tank, as well as design flaws.
The type of steel, which becomes brittle in cold conditions, used in the molasses tank that collapsed on Jan. 15, 1919 was also used in building the Titanic, which sank in the icy north Atlantic April 14-15, 1912.
Puleo points to court documents from the prolonged post-molasses flood litigation which also blame design flaws for the disaster.
“When I moved to this area nearly 30 years ago, one of the first things I thought of was, ‘This is Boston. This is where the molasses tank failure occurred,” Mayville said during his luncheon talk at La Famiglia Giorgio restaurant in the North End where the disaster claimed 21 lives and caused extensive damage.
At the time he took his wife and some friends all over the North End waterfront, unable to find the site now graced with an historic marker.
“I’m an engineer and I work in the area of failure,” he said. “This has been something of interest to me for a long time.”
He said the molasses tank failure is a common subject of study in college courses dealing with the strength of materials.
Like Puleo, Mayville uses the 25,000 pages of court testimony in his research. As a project done in his spare time, Mayville is about 8,000 pages through.
Archival material left to Lehigh University, once owned by a consultant who was among experts testifying at the trial, has also been valuable, Mayville said.
“You can have your own molasses tank already broken,” he said of online directions available for building a model. “I have one. We keep it on our fireplace mantel.”
Mayville’s interest is in using modern research techniques, such as finite element analysis, to learn why the tank failed — he believes progress is being made.
He is currently working on a computer animation of how he believes the tank collapsed, which in effect presents a graphic illustration of Puleos’s desciption of observances reported by Suffolk County Medical Examiner Dr. George Burgess Meredith in the days following the disaster:
“Steel plates from the tank’s wall lay broken and partially submerged in molasses,” Puleo wrote. “But McGrath saw that the tank’s large circular roof lay right-side-up atop the concrete foundation, in sharp contrast to the violence and destruction on the waterfront. It was as if the molasses had spewed out in all directions from under the roof, carrying the tank’s walls in all directions, but the roof had settled gently onto the ground below.”
Molasses is 1.5 times heavier than water, which also played a role, according to Mayville. While the tank had been filled to capacity several times before, at least once to a higher level than on Jan. 15, 1919, that also contributed to the ultimate failure.
“You know the famous paper clip [example], if you bend the paper clip back and fourth enough times it will break, that’s known as fatigue,” he said. “I believe something like that was happening as well.”
Another of his hypotheses is that the reputable firm that built the tank may have designed it for water.
“That’s a big mystery to me, how they could have made such a big mistake,” he said.
Welding, which was known at the time, was not widely used. The tank, again like the Titanic, was assembled with riveted joints.
“Today I would say bolts and welding is stronger,” he said. “But [rivets] was the technology of the day.”
Rivets reinforcing the outside of the manhole on the tank roof were insufficient, Mayville argues. He points to “herringbone” marks in the steel that indicate where a fracture started — in this case the manhole.
“The way they made the rivet holes in those days was to actually punch through the metal,” he said. “If you didn’t do it carefully, and sometimes if you did, it tended to damage the material around the edge of the hole — sometimes even leaving cracks.”