rightlibrary.blogg.se

There was a major fracture that went up to the manway, one underneath,” he says.

“We know that for the fracture of brittle steels, the herringbones make little arrows that point back to the location where the error started.

And when the remains of the tank were inspected, Mayville relates, there were herringbone patterns leading across the metal to the top and bottom of the manway. In addition to the stress concentrated around the hole of the manway opening, the outer part of the hatch was riveted to the steel in such a way it created a great deal of stress on the top-most rivet hole. The tank was also pierced with a hatch called a manway. Add to that, any time you cut a hole in a sheet of metal under tension, stress builds up around the hole. But it is possible that in their haste, the tank’s builders did not take this step. To compensate, you usually shave off that layer, so only the metal surrounding it is full-strength. When you punch holes in steel to thread rivets through, it makes the surface of that metal around the hole brittle. One of them concerns the tank’s rivets, which probably made that machine-gun-like sound when they popped free. And by poring over 20,000 pages of testimony from the trial, Mayville has found a few telling details. He makes his living doing the kinds of tests and calculations required to make sure such structures built today are safe. Over the last few years, Ronald Mayville, a Boston-based structural engineer, has been investigating what exactly went wrong in more detail, using modern techniques. At the time, one of many experts who testified in the case noted that the walls of the tank were thinner than the plans called for and used fewer rivets than would have been standard. Ultimately, however, the US Industrial Alcohol Company was found liable for the disaster, after six years of litigation. There was much speculation at the time that the tank might have been blown up by Italian anarchists. The curving sheets of steel that had made up the tank were borne along on the tsunami of viscous liquid sugar, crashing through everything that stood in their way. “The buildings seemed to cringe up as though they were made of pasteboard,” the Globe wrote. It picked people up and slammed into the elevated rail tracks nearby with such force that the metal crumpled. “Once the low, rumbling sound was heard no one had a chance to escape.” A wall of molasses reported to be 25-feet-high (7.5 metres) came heaving away from the collapsing tank. “The explosion came without the slightest warning,” the Boston Globe reported the next day. Then, at 12:40pm, there was a sound like machine gun fire and a terrible wrenching groan. North End was going about their business as usual. But on 15 January 1919, all hell broke loose. The tank’s presence had been uneventful for the four years since it had been built. Local children flocked to sneak a treat from the drippage, but it made at least one of the company's employees nervous. As Stephen Puleo, author of the book Dark Tide, says, it leaked dripping sticky black goo from its riveted seams. The tank had been built in a bit of a hurry. The molasses came from the West Indies to be converted into industrial ethanol by the tank's owner, the US Industrial Alcohol Company, who had been selling it for use in munitions for the Great War. But there have been moments when all was not well, and the results have been shocking – for instance, when what appear to have been design failures led to one of the oddest man-made disasters of the last century: The Great Molasses Flood of 1919.Īn enormous steel tank containing 2.3 million gallons (8.7 million litres) of molasses was a familiar landmark in Boston’s North End, looming above a playground, a fire station, and private homes. That subway tunnel will keep its shape that bridge will stay up that elevator to the 39th storey isn't going to plummet earthwards, unless you ask it to.Įngineers tasked with ensuring public safety do a remarkably good and thorough job. As we go about our daily lives, we have a fairly reasonable expectation that the objects around us will continue to maintain their structural integrity.