In late 2014, thousands of manhole explosions were reported in New York City. This is a serious problem: manhole covers weigh 50 pounds, and can do real damage to cars or pedestrians when they’re rocketing through the air. The explosions are caused by exposed wires underground, which release flammable gasses when their insulation deteriorates. This gas is then sparked by another wire and BOOM!
And as those who work in city infrastructure have begun to notice, cold winters accelerate the problem. Why? The salt on the roads in winter worsen the situation by corroding wire insulation at a faster pace. The more exposed wires, the more likely an explosion becomes.
Enter Massachusetts’ Electric Power Research Institute. which is working on a solution. It has spent years getting to the bottom of this disruptive phenomenon by intentionally causing explosions in its “Manhole Event Area,” full of built-to-scale replicas of underground electrical systems in San Francisco and New York.
One possible answer to this problem involves the placement of sensors underground to warn of gas build up. Crews would be alerted to clear the gas before an explosion occurs. Another would be to develop fancy latching manholes which could raise slightly in the case of an explosion, releasing the underground pressure without flying off the ground. With luck, in not too long, exploding manholes will be a thing of the past. In the meantime, have fun worrying about something new!