The Siemens Nexas is a class of electric multiple units manufactured by Siemens Transportation Systems for the suburban railway network of Melbourne, Australia between 2002 and 2005. The design of the trains was based on the Siemens Modular Metro. History In March 2000 M>Train ordered 62 Siemens Nexas trains to fulfill a franchise commitment to replace its fleet of Hitachi trains. The original order was for 62 3-car sets, with an option for an additional ten 3-car sets. In December 2002 just before the first was delivered, National Express handed the M>Train franchise back to the Government of Victoria, thus the first Siemens Nexas trains were delivered to the government. All passed to Connex Melbourne in April 2004. The option for ten additional trains was exercised in August 2005, with the last of these delivered in January 2006. Siemens Rail Services was contracted to provide maintenance of the trains for a period of 15 years (subject to refranchising) at Newport Workshops. With the refranchising of the network to Metro Trains Melbourne in 2009, this maintenance arrangement was retained for an initial three-year period. The first entered service on 21 March 2003 with the last delivered in January 2006. Braking issues In late 2006 the trains suffered a number of braking discrepancies while in service; 14 trains overshot platforms in the space of three days. The 15 units involved in these overshoots were withdrawn from service for checks, and instructions were issued to the drivers to minimise further occurrences. By mid-January 2007, a total of 24 three-carriage trains had been impounded for testing after 20 further incidents of over-running stations since 22 December 2006. On 13 January 2007, Connex stopped running the Siemens Nexas trains as 3-car sets until the braking issue was resolved, with the result that all services (including evenings and weekends) were operated by 6-car trains. On 29 January 2007, Connex cancelled 37 peak-period services until further notice, due to the shortage of operational trains. By 1 February 2007, 38 three-car sets were withdrawn due to continuing braking failures, meaning that more than half of the Siemens Nexas fleet (or around 10% of the total fleet) was out of revenue service. Amidst the media reporting an escalating problem with the risk of the entire fleet potentially having to be suspended, Siemens issued a statement on 31 January 2008 saying that they believed there had been no evidence during