Editing Great Western Railway (section)

===Engineering features===
[[File:Brunel's Railway Bridge at Maidenhead - geograph.org.uk - 94793.jpg|thumb|right|alt=A wide tree-lined river on the left has a green bank in the right-foreground and is crossed by a low two brick-arched bridge. A tree in the middle of the river obscures part of the bridge.|[[Maidenhead Railway Bridge]]]]
More than 150 years after its creation, the original main line has been described by historian Steven Brindle as "one of the masterpieces of railway design".{{sfn|Brindle |2006|page=269}} Working westwards from Paddington, the line crosses the valley of the [[River Brent]] on [[Wharncliffe Viaduct]] and the [[River Thames]] on [[Maidenhead Railway Bridge]], which at the time of construction was the largest span achieved by a brick arch bridge.<ref>{{cite book |last= Owen |first= Professor J.B.B. |editor= Puglsey, Sir Alfred |title= The Works of Isambard Kingdom Brunel |year= 1976 |publisher= [[Institution of Civil Engineers]] |location= London |isbn= 0-7277-0030-8 |chapter= Arch Bridges | pages=89–106 }}</ref> The line then continues through [[Sonning Cutting]] before reaching Reading<ref name=Track>{{cite book |last= Chapman |first= W.G. |title= Track Topics |year=1935  |publisher= Great Western Railway |location= London | pages=51–52 |oclc=3226302 }}</ref> after which it crosses the Thames twice more, on [[Gatehampton Railway Bridge|Gatehampton]] and [[Moulsford Railway Bridge|Moulsford]] bridges.<ref>{{cite book |last= Clifford |first= David |title= Isambard Kingdom Brunel: The Construction of the Great Western Railway |year= 2006 |publisher= Finial Publishing |location= Reading |isbn= 1-900467-28-3 | pages=129–171 }}</ref> Between Chippenham and Bath is [[Box Tunnel]], the longest railway tunnel driven by that time.<ref>{{cite book |last= Swift |first= Andrew|title= The Ringing Grooves of Change |year= 2006 |publisher= Akeman Press |isbn= 0-9546138-5-6 | pages=215–249 }}</ref> Several years later, the railway opened the even longer Severn Tunnel to carry a new line between England and Wales beneath the [[River Severn]].<ref name=Walker/>

Some other notable structures were added when smaller companies were amalgamated into the GWR. These include the [[South Devon Railway sea wall]],<ref>{{cite book| last = Kay| first = Peter| title = Exeter&nbsp;– Newton Abbot: A Railway History| publisher = Platform 5 Publishing| year = 1991| location = Sheffield| isbn = 1-872524-42-7 | pages=93–108 }}</ref> the [[Cornwall Railway]]'s [[Royal Albert Bridge]],<ref>{{cite book| last = Binding| first = John| title = Brunel's Royal Albert Bridge| publisher = [[Twelveheads Press]]| year = 1997| location = Truro| isbn = 0-906294-39-8}}</ref> and [[Barmouth Bridge]] on the [[Cambrian Railways]].{{sfn|Chapman|1935|pages=225–228}}