The youth, who was described by his teachers as a technology buff and an ‘exemplary student' trespassed in tram depots to gather the information needed to perform the prank.

"He studied the trams and the tracks for a long time and then built a device that looked like a TV remote control and used it to manoeuvre the trams and the tracks," a Lodz police spokesperson told a polish Newspaper.

"He had converted the television control into a device capable of controlling all the junctions on the line and wrote in the pages of a school exercise book where the best junctions were to move trams around and what signals to change."

Problems with the signalling system on Lodz's tram network were noticed when a driver attempting to steer his vehicle to the right was involuntarily taken to the left, according to reports. As a result, the rear wagon of the train jumped the rails and collided with another passing tram.

"He treated it like any other schoolboy might a giant train set," said Lodz police.

"It was lucky nobody was killed."