--FILE--Passengers walk into or out of a crowded Metro train at a subway station in Beijing, China, 8 August 2013. European-made equipment which collects fares on the Beijing subway may be advanced, but is proving seemingly incapable of coping with Chinese passengers in a hurry. Several times a year, engineers have had to fly in from Germany to deal with various operational glitches, in particular the jamming up of the system, according to a manager with the company. Our technical experts were puzzled why the machines, which have worked perfectly in Europe for years, failed in China all the time, he said, declining to be named due to business sensitivities. In Europe, passengers keep a certain distance from each other and feed their tickets into the machine only after the person in front has passed through. But in China, impatient passengers follow closely behind each other and often insert their ticket before the gate opens for the person in front. Our German engineers assumed there would be two to three seconds between two tickets, but in China even half a second seems too long, he said.