North American railroad signals generally fall into the category of multi-headed electrically lit units displaying speed-based or weak route signaling. Signals may be of the searchlight, color light, position light, or color position light types, each displaying a variety of aspects which inform the locomotive engineer of track conditions so that he or she may keep their train under control and able to stop short of any obstruction or dangerous condition.
There is no national standard or system for railroad signaling in North America. Individual railroad corporations are free to devise their own signaling systems as long as they uphold some basic regulated safety requirements. Due to the wave of mergers that have occurred since the 1960s it is not uncommon to see a single railroad operating many different types of signaling inherited from predecessor railroads. This variety can range from simple differences of hardware to completely different rules and aspects. While there has been some recent standardization within railroads in terms of hardware and rules, diversity remains the norm.
This article will explain some of the aspects typically found in North American railroad signaling. For a more technical look at how signals actually work, see North American railway signaling.
Read more about North American Railroad Signals: Signaling Aspect Systems, Extant Mechanical and Electrical Signals, Common Signal Rule Classes
Famous quotes containing the words north american, north, american, railroad and/or signals:
“Civilization does not engross all the virtues of humanity: she has not even her full share of them. They flourish in greater abundance and attain greater strength among many barbarous people. The hospitality of the wild Arab, the courage of the North American Indian, and the faithful friendships of some of the Polynesian nations, far surpass any thing of a similar kind among the polished communities of Europe.”
—Herman Melville (1819–1891)
“The North is full of tangled things and texts and aching eyes
And dead is all the innocence of anger and surprise,
And Christian killeth Christian in a narrow dusty room,
And Christian dreadeth Christ that hath a newer face of doom,
And Christian hateth Mary that God kissed in Galilee,”
—Gilbert Keith Chesterton (1874–1936)
“The American has dwindled into an Odd Fellow—one who may be known by the development of his organ of gregariousness.”
—Henry David Thoreau (1817–1862)
“I was the conductor of the Underground Railroad for eight years, and I can say what most conductors can’t say—I never ran my train off the track and I never lost a passenger.”
—Harriet Tubman (1821–1913)
“The term preschooler signals another change in our expectations of children. While toddler refers to physical development, preschooler refers to a social and intellectual activity: going to school. That shift in emphasis is tremendously important, for it is at this age that we think of children as social creatures who can begin to solve problems.”
—Lawrence Kutner (20th century)