Editing X 2000 (section)

== Background and development ==
[[File:X2000.jpg|thumb|An X&nbsp;2000 in original livery at [[Copenhagen Central Station]] in September 2005|left]]The X2 was developed to address the challenges posed by [[Rail transport in Sweden|Sweden's railway network]], which features numerous sharp curves (like in almost all countries) due to the country's geography.<ref>{{Cite web |title=Sweden: Renewable wins the train race - Nordic Investment Bank |url=https://www.nib.int/cases/sweden-renewable-wins-the-train-race |access-date=2025-02-10 |website=www.nib.int |language=en}}</ref> At the same time, Sweden’s low population density made the construction of dedicated high-speed rail lines impractical before 1990.

To overcome these constraints, the X2 was designed as a tilting train, allowing it to maintain theoretically 15 % higher speeds while navigating curves. Tilting trains can comfortably travel through curves up to 15 % faster speeds than conventional non-tilting trains, without the need for significant infrastructure changes.<ref>{{Cite web |title=Train Tilting Systems {{!}} Curtiss-Wright Defense Solutions |url=https://www.curtisswrightds.com/products/motion-control/industrial/train-tilting-systems |access-date=2025-02-10 |website=www.curtisswrightds.com |language=en}}</ref>

The X2 project began in 1969 as a collaboration between [[Kalmar Verkstad]], [[Statens Järnvägar]], and [[ASEA|Asea]]. Testing started in the 1970s.<ref>{{cite news |access-date=2018-02-12 |title=Därför gick SJ:s miljardsatsning till gamla X2 |lang=sv |newspaper=Ny Teknik |url=https://www.nyteknik.se/fordon/darfor-gick-sj-s-miljardsatsning-till-gamla-x2-6400824}}</ref>

In the late 1960s, an [[SL X1|X1]] multiple unit was modified with a [[Tilting train|tilting carbody]] on new Asea bogies with pneumatic cylinders. Later, an [[SJ X5|X5]] train was adapted for high-speed tests designated X15, featuring hydraulic tilt cylinders. X15 data informed X2 development, and an X2 prototype car (X15-4) was tested in the same trainset. In August 1986, [[SJ AB|SJ]] ordered the first X2 trainsets from Kalmar Verkstad and Asea.

Manufacturing introduced new welding and structural techniques, producing a rigid, collision-absorbing body with reduced corrosion and maintenance needs.<ref>{{cite web |title=Stainless steel in X2000 was a sustainable investment |url=http://www.svenskverkstad.se/rostfritt-stal-i-x2000-var-en-hallbar-satsning |accessdate=2018-06-14 |language=en-US}}</ref>

The X2 influenced later trains, including the [[SL C20|C20]] (Stockholm metro), [[Bombardier Regina]], [[Øresundståg#Rolling stock|X31]], the [[NSB Class 71]] in Norway, and the [[Alstom Movia|Bombardier Movia]] series.[in what way?]

The X2 entered commercial service on 4 September 1990 between [[Stockholm]] and [[Gothenburg]].<ref>[http://www.banverket.se/sv/Sveriges-jarnvagsmuseum/Huvudrubriker/Om-Sveriges-jarnvagsmuseum/Historia.aspx ''Sveriges järnvägsmuseum'']</ref> Production ended in March–April 1998.