A lost helium balloon caused hours of delays for Dutch rail travelers last week when it shorted out electric power for lines running through Schiphol Airport. Nearly all regional and long-distance service from the south passes through the airport’s station.
Helium balloons are generally made of mylar, which is an aluminized polyester; its aluminum coating can conduct electricity, which is exactly happened when the wayward balloon drifted up and contacted several of the overhead power lines.
In a little-known rule, bringing helium balloons onto train platforms is banned, but apparently little enforced; they are even sold in the airport as gifts for arriving passengers.
