Sydney Trains M set

The Sydney Trains M sets or Millennium trains are a class of electric multiple unit operated by Sydney Trains in Sydney, New South Wales, Australia. The fourth generation trains entered service from 1 July 2002 after short delays due to electrical defects. The trains can operate over the entire suburban network, but currently only operate on T2 Inner West & Leppington, T3 Bankstown, T5 Cumberland, T6 Carlingford, T7 Olympic Park and T8 Airport & South lines.

The M sets replaced the 1960s Tulloch trailers and provided extra capacity on the CityRail network.

Design
The Millennium train, like the entire Sydney Trains fleet and electric NSW TrainLink fleet, is a double decker. It is a four car consist, with the middle two cars being non-control motor cars and the two outer cars being driving control trailer cars fitted with the pantograph. The Millennium train is equipped with an AC drive system, whereas the Tangara has a DC drive system. The sets usually operate in eight-car formations with two four-car sets combined.

While the Millennium train concept is an evolution of the Tangara concept (manufactured by A Goninan & Co), the Millennium train introduced new features such as internal electronic destination indicators, automated digital voice announcements for upcoming stops, a return to reversible seating, surveillance cameras, wider stairways, a new safety yellow colour scheme, and push-button opened internal doors. The Millennium Train also introduced crumple zones to absorb impact in a collision. Interiors were designed by Transport Design International.

The Millennium train features Scharfenberg couplers.

Delivery
The cars were constructed by EDi Rail at Cardiff Workshops. The contract included a 15-year maintenance agreement with EDi Rail to maintain the trains at a specialised maintenance centre at Eveleigh. During testing and initial revenue service, they ran as four car sets, with eight car sets commencing service towards the end of 2002 after further testing. All 35 four car sets were delivered by October 2005.

The initial order signed in October 1998 was for 81 carriages, in December 2002 an option was taken up for an additional 60. In February 2017, Sydney Trains exercised an option to extend Downer's maintenance of the trains for a further 10 years.

Criticisms
The Millennium trains were criticised for having several technical problems and causing problems with the CityRail network; they were referred to in the media reports as The "Mi-lemon" and "Millenni-Bug" as a result. Some of the problems were caused by insufficient power supply on the overhead to cope with the power demands of the more technologically advanced trains causing them to shut down. Software bugs also contributed to the trains' poor reliability.

The Millennium trains were withdrawn from service in April 2003 while the problems were being rectified and a full audit was carried out. They were subsequently reintroduced into service in June 2003 and have since been operating on the T2 Airport, Inner West & South, T3 Bankstown, T6 Carlingford and T7 Olympic Park lines. After the new timetable was released on 26 November 2017, M sets began as 4-car services on the T5 Cumberland line on both weekdays & weekends, along with a few 8-car Waratahs.

External Carriage Camera Trial
In late 2008 some trains were fitted with external cameras atop of carriages near the doors, testing their use for the then-future Waratah trains. These cameras were subsequently incorporated into the final design of the Waratah train.

Lines serviced
The Millennium trains typically operate on the following lines:
 * T2 Inner West & Leppington Line: Leppington or Parramatta to City Circle via Granville
 * T3 Bankstown Line: Liverpool or Lidcombe to City Circle via Bankstown
 * T5 Cumberland Line: Leppington to Richmond
 * T6 Carlingford Line: Clyde to Carlingford (weekends/public holidays only)
 * T8 Airport & South Line: Macarthur to City Circle via Airport or Sydenham