Editing Multiple unit (section)

=== Weight reduction ===  
An advantage of multiple unit trains is that they can be engineered to be lighter than [[locomotive]]-hauled trains with separate carriages, using [[lightweighting]] techniques to reduce energy use, track wear, and operating costs.<ref>{{cite web |title=Around the Bay Rail Study |url=https://docslib.org/doc/4837599/3-0-diesel-multiple-unit-assessment |website=Docslib |access-date=20 January 2025 |pages=3-1/28 |language=en}}</ref><ref>{{cite web |last1=Middleton |first1=B. |title=Economic viability of diesel light rail cars. |url=https://trid.trb.org/view/477353 |access-date=20 January 2025 |date=August 1997}}</ref> The term "light-weight train" was first used in the 1930s,<ref name="DLWT1934">{{cite book |last1=Eksergian |first1=R. |title=The Design of Light-Weight Trains |date=10 February 2023 |pages=667–701 |url=https://asmedigitalcollection.asme.org/fluidsengineering/article-abstract/56/7/667/1157761/The-Design-of-Light-Weight-Trains?redirectedFrom=PDF |access-date=3 April 2025}}</ref> with early designs such as the 1934 ''[[M-10000]]'' and ''[[Pioneer Zephyr]]'' in the United States, and Germany’s 1932 ''[[Flying Hamburger]]''.<ref name="ICC1936">{{cite book |title=New Types of Light Weight Passenger Trains: Statement No. 3639. File No. 68-E-4. |date=1936 |publisher=Interstate Commerce Commission |url=https://books.google.com/books?id=ttvNAAAAMAAJ |access-date=1 April 2025 |language=en}}</ref>

Modern light-weight multiple units typically use fewer [[bogies]] and distribute [[traction (engineering)|traction]] equipment across the train, improving [[energy efficiency in transport|efficiency]] and axle loading.<ref name="MDIPM">{{cite book |last1=Fuchs |first1=Christoph |last2=Golenhofen |first2=Franziska |title=Mastering Disruption and Innovation in Product Management: Connecting the Dots |date=7 September 2018 |publisher=Springer |isbn=978-3-319-93512-6 |page=45 |url=https://books.google.com/books?id=41ptDwAAQBAJ |access-date=1 April 2025 |language=en}}</ref> However, they require particular design attention for [[bridge]] loading and [[crosswind]] safety,<ref name="LCA&ACE">{{cite book |last1=Caspeele |first1=Robby |last2=Taerwe |first2=Luc |last3=Frangopol |first3=Dan M. |title=Life Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision: Proceedings of the Sixth International Symposium on Life-Cycle Civil Engineering |date=15 October 2018 |publisher=CRC Press |isbn=978-1-351-85756-7 |url=https://books.google.com/books?id=ECB0DwAAQBAJ |access-date=1 April 2025 |language=en}}</ref><ref name="TSCC1966">{{cite book |last1=Chilton |first1=E. G. |title=Rail gauge and rapid-transit train stability |date=December 1966 |pages=135–145 |url=https://ieeexplore.ieee.org/document/6593097 |access-date=3 April 2025}}</ref> and often include [[noise, vibration, and harshness|noise and vibration]] mitigation systems.<ref name="IFAC1999">{{cite book |last1=Persson |first1=Per |last2=Lago |first2=Thomas L. |last3=Claesson |first3=Ingvar |title=Active vibration reduction in a light weight high speed train bogie |date=1 July 1999 |pages=8764–8768 |url=https://www.sciencedirect.com/science/article/pii/S1474667017574959 |access-date=3 April 2025}}</ref>

Examples from the 21st century include the lightweight ''[[Talgo]]'' sets used in [[Spain]] and exported to [[Germany]] and [[Denmark]],<ref name="RS2024">{{cite web |last1=Batrak |first1=Oleksandr |title=Talgo Unveils New Danish Passenger Car and German ICE L Locomotive at InnoTrans 2024 |url=https://www.railway.supply/en/talgo-unveils-new-danish-passenger-car-and-german-ice-l-locomotive-at-innotrans-2024/ |website=Railway Supply |access-date=1 April 2025 |date=24 September 2024}}</ref> India’s modern ''[[Vande Bharat Express]]'' units,<ref name="MRN2023">{{cite web |title=Alstom And Medha-Stadler Consortium Bid To Make100 Lightweight Vande Bharat Train |url=https://metrorailnews.in/alstom-and-medha-stadler-consortium-bid-to-make100-lightweight-vande-bharat-train/ |publisher=Metro Rail News |access-date=3 April 2025 |date=25 February 2023}}</ref> and the upcoming ''TELLi'' fleet for [[SNCF]] regional lines in [[France]].<ref name="SNCF">{{cite web |title=Revitalizing rural rail lines with TELLi |url=https://www.groupe-sncf.com/en/innovation/local-mobility/telli |website=SNCF Group |access-date=20 January 2025 |language=en |date=12 March 2024}}</ref>