Editing Railroad switch (section)

=== Three-way switch ===
[[File:ThreeWayStub.jpg|thumb|A three-way stub switch at Sheepscot station on the [[Wiscasset, Waterville and Farmington Railway]]]]

A ''three-way switch'' is used to split a railroad track into three divergent paths rather than the more usual two. There are two types of three-way switches. In a ''symmetrical three-way switch'', the left and right branches diverge at the same place. In an ''asymmetrical three-way switch'', the branches diverge in a staggered way using two [[#Interlaced turnout|interlaced turnouts]]. Both types of three-way switches require three frogs.

The complexity of symmetrical switches usually results in speed restrictions, therefore three-way switches are most often used in stations or depots where space is restricted and low speeds are normal. Symmetrical switches were used quite often on Swiss narrow-gauge railways. Asymmetrical three-way switches are more common, because they do not have speed restrictions compared to standard switches. However, because of their higher maintenance cost due to special parts as well as asymmetric wear, both types of three-way switches are replaced with two standard switches wherever possible.

In areas with very low speeds, like depots, and on railroads that had to be built very cheaply, like logging railroads, three-way switches were sometimes built as stub switches.