On this date in 1921, one of the worst industrial disasters in history occurred in Oppau, Germany. A fertilizer stockpile in a chemical plant exploded, killing an estimated 500-600 people and injuring thousands; in addition to destroying 80 percent of the buildings in the town around it. The blast, the equivalent of one-to-two kilotons of TNT, left a football field-sized crater that was 60 feet deep.
The factory, owned by the German company BASF, manufactured ammonium sulfate and ammonium nitrate fertilizer and stored 4,500 tons of the products mixed together in a tower silo. The problem started because ammonium nitrate is more hygroscopic—i.e. it absorbs more water from its surroundings—than ammonium sulfate. As a result, the two substances would bind together and form a solid clog in the silo, making it difficult to remove either of them. Workers struggled to break up the mess with pickaxes—a dangerous proposition, since it brought the risk of being buried alive in a cave-in. So instead, as this BBC article details, someone decided to drill holes in the fertilizer pile and insert strategically-placed charges of dynamite. It was a method that had been used successfully many times with ammonium sulfate. What plant officials didn’t realize was that the other fertilizer, ammonium nitrate, had different properties. When it is exposed to the force of a detonating charge, it rapidly and violently decomposes into oxygen and other gases. (That’s the reason that domestic terrorist Timothy McVeigh, who blew up a federal building in Oklahoma City in 1995, chose to use an ammonium nitrate-based fertilizer bomb.)
And with that, here are the science and technology stories of the day.Space Shuttle Discovery rolls out to launch pad for the last time today. The workhorse spacecraft has spent the equivalent of a year in orbit.
Earth’s highest coastal mountain is moving. Columbia’s Sierra Nevada de Santa Marta is rotating, which will create a new geological basin.
Arctic bacteria hibernate for as long as 100 million years. Now, that’s a nap for you.
Proposed law would empower federal agents to shut down music and movie piracy web sites worldwide. Some in Congress think national sovereignty has become obsolete in the Internet age, apparently. We’ll see what other countries think of that.
Lasers can make molecules super-cool. This breakthrough may hasten the development of nano-scale computers.
Giant spiders cast web over river, using super-material. It’s the strongest silk ever discovered.