UK-based train operator South West Trains has begun operating new 10-car regular passenger trains between Windsor and Waterloo.
The move forms a part of the delivery of a multi-million-pound investment programme to improve rail services on the busiest commuter rail network in the country.
The 10-car passenger trains will be used to operate 14 different train services between London Waterloo and Windsor every weekday.
Around 98 carriages will further be launched to provide passengers with extra space during peak times of travel between the two points, over the next one year.
The Department for Transport will redesign Waterloo and the surrounding area to enable the introduction of more additional trains.
UK Rail Minister Stephen Hammond said: "We are investing record amounts into transforming our railways and it is great to see this investment delivering real benefits to passengers, local businesses and the economy.
"These much-needed carriages will provide a welcome boost to commuters through additional trains and services, allowing more people to travel on these vital commuter routes."
Platform 20 of the former Waterloo International station is slated for re-opening for full passenger services from 19 May.
Meanwhile, plans are being made to deliver a short-term solution to re-open Platforms 21 and 22 of the Waterloo International Terminal later this year.