For much of WWII, the Netherlands were in the hands of the Nazis. As a result of this, one of the tram lines in Amsterdam's tramway network was used to deport Jews and, therefore, the number has never been used again. This was line 8 and was in use from 1905 to 1942. Other lines were also discontinued after the war, including lines 6, 14, 22 and 23, although 14 is now in use as a bus route.
There have been a lot of tram lines discontinued over the years. There are 12 line numbers that have been in use in the past that are no longer used, and a total of 27 have been used. Those all numbered 1-27, while 30 is used informally by the Electric Tramway Museum Amsterdam. Numbers 28 and 29 have never been used.
