and on 28 March 1998, line 16 (Moillesulaz–Cornavin) was put into operation. On 14 December 2003, line 13 was extended from Cornavin to Nations. The following year, on 11 December 2004, line 15 entered service; it ran on a new route from Lancy-Pont-Rouge via Acacias to Plainpalais, and continued from there via Cornavin station to Nations. From 10 December 2005, this new section was also served by line 17, which ran from Plainpalais to Eaux-Vives station. Due to the increased need for rolling stock resulting from the network expansions after 2000, more trams were procured. Initially, the TPG ordered 21 Flexity Outlook Cityrunners from Bombardier Transportation for delivery in 2004-2005, with an option on another 17 vehicles; the option was exercised at the end of 2007. On 13 May 2006, upon the entry into service of a new section between Palettes and Lancy-Pont-Rouge, the ring link was completed, and with it the first phase of the network's expansion. The new ring link section facilitated the extension of line 15 and line 17 to Palettes and Bachet, respectively. From the day the ring link was completed, the four tram lines operating on it, lines 12, 13, 15 and 17, no longer terminated there, but changed their numbers at designated stops: line 12 became line 17 at the Bachet stop, and line 13 became line 15 at the Palettes stop. In 2009, there was another alteration in the way the lines serviced the ring link: line 12 began switching to line 15 at the Palettes stop, line 13 started to reverse at the Palettes loop and line 17 was redirected to turn around at the Lancy-Pont-Rouge loop. TCMC and TCOB construction (2007–2011) The next network expansion phases included the Tram Cornavin–Meyrin–CERN (TCMC) project, the construction of which began in early 2006, and the Tram Cornavin–Onex–Bernex (TCOB), for which the Swiss Federal Council awarded the concession in January 2007. The first section of the TCMC, between Cornavin and Avanchet, was opened on 8 December 2007. Initially, it formed part of the extended line 16 (Moillesulaz–Avanchet) and the new line 14 (Bachet–Avanchet). On same date, line 17 was extended, from Eaux-Vives station to the disused Chêne-Bourg station, and thus revived scheduled services on the short local branch line, including its terminal loop, after a long absence. The first TCMC section was built in a double track configuration. However, the absence of any balloon loop