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:
“What is done for science must also be done for art: accepting undesirable side effects for the sake of the main goal, and moreover diminishing their importance by making this main goal more magnificent. For one should reform forward, not backward: social illnesses, revolutions, are evolutions inhibited by a conserving stupidity.”
—Robert Musil (1880–1942)
“The line of separation was very distinct, and the Indian immediately remarked, “I guess you and I go there,—I guess there’s room for my canoe there.” This was his common expression instead of saying “we.” He never addressed us by our names, though curious to know how they were spelled and what they meant, while we called him Polis. He had already guessed very accurately at our ages, and said that he was forty-eight.”
—Henry David Thoreau (1817–1862)