X'Trapolis 100

Since their introduction to the suburban network in 2002, the trains operated only on the former Connex Melbourne Hillside Trains network (which consisted of the Burnley and Clifton Hill group lines), and did not run revenue services elsewhere operated by M>Train on the Bayside Trains half of the system, despite the two networks merging in 2004.

On 22 October 2014, the operation of X'Trapolis 100 trains was expanded to include lines on the former Bayside Trains network with the Frankston line being cleared for their operation and initially running two weekday morning-peak services.

On 20 November 2016, X'Trapolis 100 trains were expanded to full-time running on the Frankston line and began operating services on the Werribee and Williamstown lines the same day.

Although Melbourne's trains operate as either one or two 3-car units, it was not until September 2007 that the X'Trapolis 100s were permitted to operate as single-units in revenue service.

The trains have power-operated doors that open when a button on the door is pressed and are closed by the driver or closed automatically after approximately thirty seconds.

The X'Trapolis 100s are currently the only suburban trains in Melbourne with external destination displays on the sides of the carriages with this feature only seen on the diesel powered Sprinter and VLocity rail motors.

Several trains were given names: Croydon West (primary school that won a naming contest), Don Corrie (deceased railway employee),[28] Flash, Flinders Flyer, Iramoo (primary school that won a naming contest), Melbourne Rocks and Westernport. X'Trapolis 100 863M-1632T-864M-897M-1649T-898M was the first Melbourne train to receive the new ‘Metro’ livery in November 2009, in preparation for the launch of the new suburban operator.[29] When the Connex livery was retired in place of the current Metro design, the Iramoo name (shown on units 851M and 852M) was erroneously written as Imaroo. This spelling is still unchanged as of August 2018.

In November 2018, X'Trapolis 100 trains’ operations were expanded to the Flemington Racecourse line.

As part of its 2009 franchise agreement, Metro Trains Melbourne was required to modify the 3+2 seating layout in all original X'Trapolis 100s to have 2+2 seating, providing efficiency in passenger flow and more standing room.

Later orders of X'Trapolis 100s were delivered with this modified layout.[30][31] Passengers on the Lilydale/Belgrave Line came to refer to trains made up of these cars as the 'Kosky Express' in reference to the late Lynne Kosky MLA who had been accused, as Transport Minister, of indifference to the needs of the eastern suburb's populace in pursuing policies which resulted in a reduction in the number of seats available on the 40-km trip into Melbourne by train.[32]

Mechanically, these trains are very different from the previous generation Melbourne trains. The X'Trapolis 100 was the first EMU in Melbourne to have computer-controlled traction, braking and safety systems. A continuous electrical circuit runs along the length of the train, which, when energised allows the train's emergency brakes to release. The circuit will be de-energised by a number of events, such as the driver releasing a vigilance control, applying an emergency brake or passing a signal at stop. This will cause the train to apply all brakes.

On 26 September 2009, 872M crashed into a car between Croydon and Mooroolbark, derailed on impact and destroyed an overhead power stanchion. The Ford Fairmont had crashed down the embankment onto the tracks and was abandoned prior to the train collision.

On 12 May 2010, an almost brand new 9M overran a siding in Ringwood, derailing and crashing into the siding fence. The train had entered service less than a month prior.

On 24 March 2011, 920M overran the dead-end platform at Macleod, crashing into the fence at the end of the platform. Prior to the accident, the platform had recently been washed and the soapy water had ended up on the tracks causing a complete loss of friction. Additionally, it was found that the end-of-line baulks (two wooden sleepers placed across the rails in lieu of a buffer stop) were also defective; the train wheels simply pushed them along the rails.

On the morning of 11 November 2015, an individual later identified as a then Metro employee gained access to the cabin of an X'Trapolis 100 6-car set stored at the depot of Hurstbridge station and drove it into a derail block, causing it to be derailed. 927M received the most damage in the incident from ploughing into an adjacent X'Trapolis set, whilst other carriages and track equipment were damaged. All carriages are expected to be back in revenue service after being repaired.[33][34]

On 6 February 2016, 9M derailed its trailer car (1305T) just before Rushall station city-bound,[35] where the track is a very tight 30 km/h bend. The South Morang line was partially suspended while the car was placed back onto tracks.

On 9 November 2018, a Lilydale-bound service, led by 959M, uncoupled in running shortly after departing Croydon Station, splitting into two 3-car units, with the trailing unit coming to a stop under emergency braking. The subsequent investigation found that a wiring error during a modification to the train's low-note whistle on 959M, combined with a deterioration of insulation resistance in the uncouple solenoid connector of 882M (the leading car of the trailing unit), resulted in an error circuit forming which resulted in the unintended coupling.[36]

Unlike their Australian peers, Merval's cars do not have intermediate cars, they only consist of two cars with a cabin, one motor (which has the pantograph) and another trailer. They can also operate as double units, forming convoys of 4 wagons, but always smaller than the Australians.

The door system is the same; Automatic doors that are activated by pressing a button on the door and are closed by order of the driver or after two minutes. Each car has 3 passenger doors per side, which gives a total of 6 accesses per single car and 12 per double convoy.

Each car has a single pantograph that delivers energy to the motor car from the catenary available throughout the network.

Due to the lack of a catenary, the trains do not operate beyond the Limache station, although the possibility of extending Merval's service to La Calera is being analyzed.

Contrary to what was done in Australia, Merval announced a reduction in seat capacity of its trains, to be implemented between October and December 2014.  This reduction seeks to increase train capacity to meet the growing demand of passengers. Although exact figures were not provided, a reduction of approximately 46 seats per train is expected, to be homologated to the 96 that the X'Trapolis Modular has, a model of which 8 units will arrive in 2015 to reinforce Merval's service.

In a pioloto plan between state copper company Codelco and Alstom, 1 car was modified to include antimicrobial copper in the handrails and contact areas.  The modification, which included the removal of handles and panels, is part of the search for new uses for copper that Codelco carries out as part of its market development plan.

However, months later, the copper railings were removed and the car returned to its original condition.