A gap in the public transport network had to be closed in time for the 2004 Olympics in Athens. The project involved connecting up the metro between the new Eleftherios Venizelos International Airport and the city center. The underground work was performed by an EPB machine (S-188) with a diameter of 9.46 meters. Ring for ring, it constructed a 3.5-kilometer-long tunnel for metro line 3 in the east of the city. During the tunnelling process, the TBM had to advance at overburdens between 6.5 and eight meters, before finally reaching its destination after only 13 months.