The main line or mainline (American English) of a railway is a track that is used for through trains or is the principal artery of the system from which branch lines, yards, sidings and spurs are connected.
It generally refers to a route between towns, as opposed to a route providing suburban or metro services. For capacity reasons, main lines in many countries have at least a double track and often contain multiple parallel tracks.
Main line tracks are typically operated at higher speeds than branch lines and are generally built and maintained to a higher standard than yards and branch lines.
Railway points (railroad switches in the US) are usually set in the direction of the main line by default. Failure to do so has been a factor in several fatal railway accidents, for example the Buttevant Rail Disaster in Ireland, and the Graniteville train disaster in the US.
Main lines may also be operated under shared access by a number of railway companies, with sidings and branches operated by private companies or single railway companies.
In the UK, the term "main line" may also be used to distinguish any train or track that is not part of a light-rail or underground network.
Famous quotes containing the words main and/or line:
“But oh, not the hills of Habersham,
And oh, not the valleys of Hall
Avail: I am fain for to water the plain.
Downward, the voices of Duty call—
Downward, to toil and be mixed with the main,
The dry fields burn, and the mills are to turn,
And a myriad flowers mortally yearn,
And the lordly main from beyond the plain
Calls o’er the hills of Habersham,
Calls through the valleys of Hall.”
—Sidney Lanier (1842–1881)
“Every age has its temptations, its weaknesses, its dangers. Ours is in the line of the snobbish and the sordid.”
—Rutherford Birchard Hayes (1822–1893)