The Great Western Main Line (GWML) is a main line railway in England that runs westwards from London Paddington to Bristol Temple Meads. It connects to other main lines such as those from Reading to Penzance and Swindon to Swansea. Opened in 1841, it was the original route of the first Great Western Railway which was merged into the Western Region of British Railways in 1948. It is now a part of the national rail system managed by Network Rail with the majority of passenger services provided by the current Great Western Railway franchise. The line has recently been electrified along most of its length. The eastern section from Paddington to Hayes & Harlington was electrified in 1998. Work to electrify the remainder of the route started in 2011 with an initial aim to complete the work all the way to Bristol by 2016, but in that year the section through Bath to Bristol Temple Meads was deferred with no date set for completion because costs had tripled.
