HKL Class M100

The HKL Class M100 is the first and oldest class of metro trains in use on the Helsinki Metro. One train consists of two individually numbered cars. A total of 42 car pairs (84 cars in total) were manufactured between 1977 and 1984.[2][3]

HKL class M100
A refurbished M100 train, July 2011
Interior of a M100 carriage
In service	1982–present
Manufacturer	Valmet, Strömberg
Assembly	Tampere, Finland
Constructed	1977–1984
Refurbished	Talgo Oy, Otanmäki (2007–2009)
Number built	84 cars (42 pairs)
Successor	M200
Formation	4 cars per trainset (until 2016 also 6 cars per trainset during rush hour)
Fleet numbers	101–184
Capacity	65 seats (per car, one train consists of two cars)
Operator(s)	Helsinki City Transport (HKL)
Depot(s)	Roihupelto Depot[1]
Line(s) served	Helsinki Metro: M1, M2
Specifications
Train length	44.2 m
Width	3.2 m
Height	3.7 m
Doors	3 pairs per side
Maximum speed	100 km/h

Up to six pairs can be combined into a 12-car train formation, however due to the relatively short length of the platforms (especially on the new Länsimetro extension), at most only two pairs (giving a 4-car formation per train; and prior to the Länsimetro opening in 2017 three pairs resulting in 6-car formations could also be seen during rush hour) can be combined for passenger service. Longer combinations are used in maintenance operations. Any Helsinki metro train types can be combined mechanically, such as for towing.

The first three units (cars 101–106) were constructed as prototypes in 1977 and have some minor technical differences compared to the later units. The prototype units are no longer in active use.

The M100 trains underwent its first round of refurbishment in 2007–2009, at the Talgo Oy (now Škoda Transtech) rolling stock works at Otanmäki. In 2017, the City Council of Helsinki decided to refurbish class M100 and class M200 trains in order to extend their lifetime for another 10 years. The renovation will start in late 2019 and will be completed by government-owned VR Kunnossapito Oy. It is planned to delay acquiring new metro trains for the potential automation of the metro system, due to the decision to cancel the contract to automate the Helsinki Metro in 2015. The prototype trains (101–106) will not be renovated.[4][5]