:British Rail Class 398

{{Short description|Future electric multiple unit to work in South Wales}}

{{Use dmy dates|date=January 2019}}

{{Use British English|date=March 2017}}

{{Infobox train

| background = #AE0000

| name = British Rail Class 398
Citylink

| image = TfW Rail 398027 at Abercynon 16 April 2025.jpg

| imagealt =

| imagesize =

| caption = Class 398 on test at Abercynon in April 2025

| interiorimage =

| interiorimagealt =

| interiorcaption =

| stocktype =

| service = Planned for 2025{{cite web |title=Key performance indicators for customers|url=https://tfw.wales/about-us/transparency/key-performance-indicators/customers#:~:text=We%20expect%20that%20the%20Class,also%20improving%20our%20service%20performance. |access-date=2 October 2024 |publisher=Transport for Wales }}

| manufacturer = Stadler Rail

| assembly = Stadler Rail Valencia SAU

| factory = Valencia, Spain

| family = Citylink

| replaced = {{ubl|{{brc|150}}|{{brc|153}}}}

| yearconstruction = 2020–present{{cite news |title=Trains for Wales under construction |url=https://www.railwaygazette.com/uk/trains-for-wales-under-construction/57931.article |access-date=7 December 2020 |work=Rail Business UK |publisher=DVV Media International |date=2 December 2020 |archive-url=https://web.archive.org/web/20201202120522/https://www.railwaygazette.com/uk/trains-for-wales-under-construction/57931.article |archive-date=2 December 2020 |location=Sutton}}

| yearservice =

| refurbishment =

| yearscrapped =

| numberconstruction = 36

| numberbuilt =

| numberservice =

| numberpreserved =

| numberscrapped =

| formation = 3 cars per unit

| fleetnumbers = 398001–398036

| capacity = 252
(126 seated, 126 standing)

| owner = SMBC Leasing{{cite magazine |title= Time to take stock as the 'bubble' bursts…|magazine=Rail Magazine |issue=989|date=9 August 2023 |pages=42–47}}

| operator = Transport for Wales Rail

| depots = Taff's Well{{cite news |title=Taff's Well metro depot construction started by Transport for Wales |url=https://www.railway-technology.com/news/taffs-well-metro-depot-tfw/ |access-date=28 January 2023 |work=Railway Technology |publisher=Verdict Media |date=20 January 2020}}

| lines =

| carbody = Stainless steel

| trainlength = {{cvt|40.07|m|ftin|0}}

| carlength =

| width = {{cvt|2.650|m|ftin}}

| height =

| floorheight = {{cvt|915|mm|in|0}} at doors

| platformheight =

| entrylevelorstep =

| doors = Double-leaf sliding plug
(1 per side per vehicle)

| wheeldiameter = {{cvt|740|mm|in|0}}

| wheelbase =

| maxspeed = {{convert|100|km/h|0|order=flip|abbr=on}}

| weight =

| axleload =

| traction =

| traction motors = 4 × TSA TMR 42-31-4,
each of {{cvt|150|kW|hp|0}}{{cite web |title=Stadler Rail Citylink for Keolis CVL Cardiff, Wales |url=https://www.tsa.at/tsa_referenzen/stadler-rail-citylink-for-keolis-cvl-cardiff-wales/ |publisher=Traktionssysteme Austria |place=Wiener Neudorf |access-date=28 January 2023}}

| poweroutput = {{cvt|600|kW|hp|0}}

| tractiveeffort =

| transmission =

| acceleration =

| deceleration =

| aux =

| powersupply =

| hvac =

| electricsystem = {{25 kV 50 Hz}} overhead

| collectionmethod = Pantograph

| uicclass = Bo′+2′2′+Bo′

| bogies =

| minimum curve = {{cvt|25|m|ft|0}}

| brakes =

| safety =

| coupling =

| multipleworking = Within class

| gauge = {{track gauge|uksg|allk=on}}

| notes = Sourced from {{cite book |title=Citylink Tram Train, Transport for Wales |date=September 2022 |publisher=Stadler Rail Group |location=Bussnang |id=CTTWB0922e |url=https://www.stadlerrail.com/media/pdf/cttwb0922e.pdf |access-date=28 January 2023 |archive-url=https://web.archive.org/web/20220920170439/https://www.stadlerrail.com/media/pdf/cttwb0922e.pdf |archive-date=20 September 2022 |url-status=live}} except where otherwise noted.

}}

The Class 398 Citylink{{cite tweet |author=Transport for Wales Rail |user=tfwrail |number=1201451939856355328 |date=2 December 2019 |title=Our Metro tram-trains, which will run on the Treherbert, Aberdare and Merthyr lines from 2022, will be Class 398 }} is a fleet of 36 tram-train multiple units being built for Transport for Wales Rail by Swiss rolling stock manufacturer Stadler Rail.

The units will be equipped with traction battery packages, allowing them to operate over non-electrified sections of track in addition to those with {{25 kV 50 Hz}} overhead supplies.