Editing Train stop (section)

==Installations==
In 1901, [[Union Switch and Signal|Union Switch and Signal Company]] developed the first [[automatic train stop]] system for the [[Boston Elevated Railway]]. This system was soon adopted by the [[New York City Subway]] and other transit systems in the United States.<ref>{{cite book |title=Automatic Block Signalling for Interurban Electric Railways |last=Union Switch and Signal Co. |year=1911 |location=Swissvale, PA |page=33 }} Bulletin No. 57.</ref> Similar systems were installed around this time on the [[London Underground]] system.

Because of its mechanical nature, the train stop has certain limitations in application. Severe snow and ice conditions, for example, could interfere with operation of the wayside trip arm. Its widest application, therefore, is on underground [[rapid transit]] lines, where conditions that might interfere with proper operation are readily controlled. It is also not suitable for high-speed operation, as the maximum speeds permitted often do not exceed 115 km/h (61 mph), citing risk of high impact forces breaking the arms.

Train stops on London Underground lines are gradually being phased out in favour of [[Automatic train protection|ATP]] and distance-to-go signalling. Train stops remain standard equipment on all [[Sydney Trains]] metropolitan passenger lines in New South Wales, and on the electrified suburban railway system in [[Railways in Melbourne|Melbourne]], Australia.

The Train stops at the Berlin S-Bahn were first installed in the late 1920s.<ref>{{cite web|url=https://www.punkt3.de/index.php?go=lesen&read=1377|title=Wenn auf dem Ostring gebaut wird …|at=Punkt 3 - Ausgabe 14 - Bauen - Seite 12|date=2011-07-03}}</ref> They are named ''{{lang|de|Bernauer Fahrsperre}}'' (or {{lang|de|Fahrsperre Bauart Bernau}}) because of their testing and first installation on the [[Berlin–Szczecin railway|Stettin Railway]] to the suburban town of [[Bernau bei Berlin|Bernau]]. This was the first [[heavy rail]] [[rapid transit]] system with third-rail electrification in Germany. They are being phased out in favour of the [[Zugbeeinflussungssystem S-Bahn Berlin|ZBS]] system based on [[Eurobalise]]s until 2025.

=== Trackside installation ===
[[File:Zugsicherung sbahn berlin.jpg|thumb|Train stop of Berlin S-Bahn]]
[[File:A signal and a tripcock north of the 125th street station.webm|thumb|A train stop of New York City Subway, just north of the 125th street station]]
* [[Berlin S-Bahn]] rapid transit uses a metal bar as the trip arm, positioned at the height of the first [[bogie]], on which the trip cock is placed. The metal bar (also named "Streckenanschlag" / track stop collar) folds away to allow passing. It is being replaced by [[Zugbeeinflussungssystem S-Bahn Berlin|ZBS]] until 2025. 
* [[Berlin U-Bahn#Kleinprofil (small profile)|Berlin U-Bahn small profile]] underground railway used a metal stick as a trip arm, which hung over the track horizontally like a semaphore signal. The trip cock was on the roof of the first wagon (near the first door) almost looking like a lightning rod.<ref name="bvg_mechanical">{{cite web |title=Die mechanische Zugsicherung bei der Berliner U-Bahn |url=http://www.berliner-verkehrsseiten.de/u-bahn/Stellwerke/Zugsicherungstechnik/Mech-Fahrsperre/mech-fahrsperre.html |website=Berliner Verkehrsseiten |access-date=2023-01-10 |language=de}}</ref> The system was phased out in the 1960s ([[West Berlin|West]]), respectively 1990s ([[East Berlin|East]]) and replaced by an inductive train stop system.<ref name="bvg_magnetic">{{cite web |title=Die magnetische Fahrsperre bei der Berliner U-Bahn |url=http://www.berliner-verkehrsseiten.de/u-bahn/Stellwerke/Zugsicherungstechnik/Magnet/body_magnet.html |website=Berliner Verkehrsseiten |access-date=2023-01-10 |language=de}}</ref>
* [[Berlin U-Bahn#Großprofil (large profile)|Berlin U-Bahn large profile]] underground railway used a mushroom-shaped swivel next to the right rail as  a trip arm. The trip cock was mounted on the first bogie. This system was replaced likewise.<ref name="bvg_mechanical" /><ref name="bvg_magnetic" />
* [[London Underground]] uses a square-shaped metal plate that functions similarly to that on the New York City Subway system.
* Several lines on the [[Moscow Metro]] use a semi-circle that rotates into position when signals are red. All of them are on the right side of tracks as trains' trip cocks are fitted on the right side.     
* [[New York City Subway]] uses a T-shaped metal bar rising from the floor as a trip arm; on the right side of the track for the [[A Division (New York City Subway)|A Division]] (numbered trains) and left side for the [[B Division (New York City Subway)|B Division]] (lettered trains). To allow trains to proceed it pivots down. A trip cock is mounted on the corner of the truck (bogie) of each car. The placement of the trip cock depends on the division the train runs on; some rolling stock is equipped with a trip cock on both sides. The train stop can be identified on the tracks because they are painted yellow for evidence if it has ever tripped a train.
* [[Sydney]] now uses the London Underground type '''J''' trip arm called the '''JA''', except that it is mirror-image mounted on the left hand side of the track instead of the right hand side. A nearly identical system is used in [[Wellington]].
* [[Toronto Subway]] also uses a T-shaped metal bar that rises from the floor except it is always on the right side of the track for all rolling stock because the trip cock is placed on the right side for all rolling stock.