Automatic train stoporATSis a system on a train that automatically stops a train if certain situations occur (unresponsive train operator, earthquake, disconnected rail, train running over a stop signal, etc.) to prevent accidents. In some scenarios it functions as a type ofdead man's switch.Automatic train stop differs from the concept ofAutomatic Train Controlin that ATS usually does not feature an onboard speed control mechanism.
Overview
editMechanical systems
editThe invention of the fail-saferailway air brakeprovided an external means for stopping a train via a physical object opening a valve on the brake line to the atmosphere. Eventually known astrain stopsortrip stops,the first mechanical ATS system was installed inFrancein 1878 with some railroads inRussiafollowing suit using a similar system in 1880.[citation needed]In 1901Union Switch and Signal Companydeveloped the first North American automatic train stop system for theBoston Elevated Railway.This system was soon adopted by theNew York City Subwayand otherrapid transitsystems in the United States.[1]
Mechanical ATS was more popular onrapid transitsystems and dedicatedcommuter railthan freight or long-distance passenger lines due to a combination of the increased complexity found in mainline railroad operations, the risk of inadvertent activation by debris or other wayside appliances, and the danger ofemergency brakeapplications at high speeds. Moreover, the forces involved in a physical tripping action can begin to damage both the wayside and vehicle borne equipment at speeds over 70 miles per hour (110 km/h).
In 1910 thePennsylvaniaandLong Island Rail Roadsinstalled a mechanical ATS system covering various lines toNew York Penn Stationusing the patented Hall trip valve which was designed to prevent inadvertent activations from debris, however the system was only installed on locomotives andmultiple unitstraveling to Penn Station and did not see further adoption.
While similar in operation mechanical systems around the world are generally incompatible due to the wide variety of vehicle dimensions and track gauge which will result in the mechanical stopping devices not engaging the onboard valve.
Electronic systems
editElectronic systems make use ofelectric currentsorelectromagnetic fieldsto trigger some action in thelocomotive cab.While mechanical systems were generally limited to venting the brake pipe and triggering an emergency stop, electronic systems can trigger other actions such as an acknowledgment from the driver, cutting power or a less severe application of the brakes. Without physical contact electronic systems could be used with higher speeds, limited only by the equipment's ability to sense the signal from stop devices.
The first such electronic system wasCrocodile (train protection system)installed on French railways starting in 1872 which used an electrified contact rail to trigger an acknowledgment from the driver. If no such acknowledgment was made in 5 seconds the train would be stopped. In the UK theGreat Western Railwayimplemented a similar system in 1906 dubbedAutomatic Train Controlthat served as the template for the magnetic basedAutomatic Warning System,which ultimately replaced it starting in the 1950s.
In the United States, theGeneral Railway Signalcorporation introduced itsIntermittent Inductive Automatic Train Stopsystem in the 1920s which made use ofinductive loopsin a "shoe" mounted outside of the running rails. This system was also of the acknowledgment type and was adopted by several railroads, continuing to see service as of 2013.[2]
In 1954, Japan introducedATS-B,the first known variant of ATS. In 1967,ATS-S(and its various supplements) was invented, the first non-contact-based ATS to be used; in 1974,ATS-Pwas used for the first time, and in 1986,H-ATSwas invented.[3][better source needed]
Usage around the world
editUnited States
editThe majority of systems meeting the definition of Automatic Train Stop in the United States are mechanical trip stop systems associated with rapid transit lines built in the first half of the 20th century. Since 1951 ATS has been required by theInterstate Commerce Commission(later theFederal Railroad Administration) as a minimum safety requirement to allow passenger trains to exceed aspeed limitof 79 mph (127 km/h). The regulatory requirement refers to a system that triggers an alert in the cab of the locomotive whenever the train passes a restrictive wayside signal and that then requires thelocomotive engineerto respond to the alert within a set period of time before the brakes are automatically applied.
The most popular implementation of ATS for the mainline railroad industry was made by theGeneral Railway Signalcompany starting in the 1920s and consisted ofinductive coilsmounted just outside the right hand rail in relation to the direction of travel. Often referred to as just ATS in railroad operating books, the full name of the system isIntermittent Inductive Automatic Train Stopto differentiate it from mechanical systems being offered at the time. The popularity of ATS as a train protection mechanism fell after the introduction oftrack coded cab signalsin the 1930s.
ATS installations in the United States
editSystem | Operator | Lines | In Service | Notes |
---|---|---|---|---|
Train stop | New York City Subway | A Division(IRT) | 1904–present | Trips right |
B Division(BMTandIND) | 1915–present | Trips left | ||
Port Authority Trans-Hudson | System-wide | 1908–present | Trips left | |
SEPTA | Broad Street Subway | 1928–present | Trips left | |
Market–Frankford Line | ?-present | Trips left, at wayside signals only | ||
MBTA | Blue Line | 1925–present | Trips both | |
Orange Line | 1901–present | Trips right, at wayside signals only | ||
Red Line | 1912–present | At wayside signals only | ||
Chicago Transit Authority | Chicago 'L' | ?-present | Trips left, at wayside signals only | |
Pennsylvania Railroad/Long Island Rail Road | New York Tunnel Extension | 1911-? | Trips right, used Hall trip valves on trains | |
Long Island Rail Road | Dunton to Flatbush Avenue[4] | ?-circa 1970 | Trips right, used Hall trip valves on trains. | |
IIATS | BNSF Railway | Santa FeChicago to Los Angeles "Super Chief"Route | 1930s-present | Parts of the route have had ATS removed |
MetrolinkandCoaster | Former ATSFSan Diego Main Line. | ?-present | In service milepost 179 to 249. | |
New York Central | New York to ChicagoWater Level Route | 1920s-1971 | Removed by successorPenn Central | |
Southern Railway | 2700 route miles of main line. | 1920s-1971 | Removed in favor of increasedCTCuse. | |
Union Pacific | FormerChicago & North WesternNorth Line,Northwest Line | 1952–2019 | Used byUnion Pacificon lines that also runMetraCommuter trains. Both freight and commuter locomotives must be equipped, with some exceptions. | |
New Jersey Transit | RiverLINE | 2003–present | Installed atinterlockingsonly. Enforces Stop. | |
Westcab | Port Authority of Allegheny County | Pittsburgh Light Rail42S Linefrom downtown to South Hills Village. | 1985–present | Some overlap with an Automatic Train Control system installed on the Route 47 Line. |
Japan
editMany trains inJapanare equipped with this system. The ATS systems in Japan are slightly similar to those used in the United States, but are nowadays primarilytransponder-based. The first mechanical ATS systems in Japan were introduced on theTōkaidō Main Linein 1921, followed by theTokyo Metro Ginza Linein 1927; but ATS did not become commonplace in the country until the late-1960s as a result of theMikawashima train crashwhich occurred in 1962. Below is a list of ATS systems that are specific to Japan only:
- ATS-B(also supplemented with S-type transponder; now obsolete since 2009)
- ATS-Dx(ATS using D-type transponder; always supplemented with: ATS-DF (JR Freight), ATS-DK (JR Kyushu) or ATS-DN (JR Hokkaido))
- ATS-S(x)(ATS using S-type transponder; always supplemented with: ATS-SF (JR Freight), ATS-SK (JR Kyushu), ATS-SM (Mizushima Rinkai Railway), ATS-SN (JR Eastand JR Hokkaido), ATS-SS (JR Shikoku), ATS-ST (JR Central) or ATS-SW (JR West), the last two letters corresponding to the type of transponder used with the S-type transponder)
- ATS-P(ATS using pattern renewal transponder; variants are ATS-PF (JR Freight), ATS-PN (Low-cost introduction type), ATS-PT (JR Central) and ATS-Ps (Frequency changecab signallingType; used for e.g. onSenseki LineandSendai Airport Line,and on operational steam trains))[5]
- D-TAS(introduced by JR West in 2012; previously calledATS-MandATS-DWduring development)
- H-ATS(formerly used on theEF66locomotive)
-
ATS pickup on the underside of aKiHa 183 seriesDMU
-
ATS-B light indicator onKiHa 59 seriesDMU
-
ATS-DK control panel
-
ATS-P indicator
-
ATS-Pscab signallingspeed indicators on KiHa 59 series DMU
-
Retrofitted equipment cabinet for ATS-P and ATS-Ps onShinano Railway115 series
In addition, various private-sector railways and subway lines have adopted their own versions of the ATS system since the 1960s. Like the ATS systems used by the railways in the JR Group, they are transponder-based as well, but are generally incompatible with the ATS systems used by JR.
- C-ATS/ATS Type 1(Used byKeikyu Corporation,Keisei Electric Railway,Shin-Keisei Electric Railway,as well as onHokusō Line,Narita Sky Access LineandToei Asakusa Line)
- i-ATS(Used byShizuoka Railwaysince 2007)
- K-ATS(Used byKeihan Electric Railwaysince 2015)
- Meitetsu ATS(M-ATS) (Used byMeitetsu)
- OM-ATS(formerly used byOdakyu Electric Railway)
- D-ATS-P(DigitalATS-P) (Used byOdakyu Electric Railway,not compatible with JR ATS-P)
- T-ATS(formerly used onToei Mita Line,similar to Tobu ATS, replaced by ATC-P)
- Tobu ATS(TSP) (Used byTobu Railway,except for the section of track between Ikebukuro and Ogawamachi on theTobu Tojo Line)
- Hankyu Railway,Hanshin Electric Railway,Kintetsu,Sanyo Electric Railway,Seibu RailwayandTokyu Corporation(Ikegami/Tamagawa lines only) all use their own proprietary ATS systems.
- Sotetsureplaced own system to JR East's ATS-P.
- Keio Corporationreplaced own system with ATC.
New Zealand
editIn Wellington only a few signals at a converging junction are fitted with mechanical ATS. All electric trains are fitted.
South Korea
editSomeKorailandsubwaylines are equipped with this system, as follows: Line 1, Line 4 (above ground section between Geumjeong and Oido stations), Suin-Bundang Line (between Gosaek and Incheon), Gyeongui-Jungang Line, and the Gyeongchun Line. The first ATS system in South Korea was installed on the Korail network in 1969, followed by Seoul Subway Line 1 in 1974 (similar to Japanese ATS-S).
Argentina
editBuenos Aires Undergroundlinesandhave ATS equipped, while,,andhave the more advancedCommunications-based train control.[6]
TheRoca Lineis ATS equipped in its electrified branches since 1985.[7]Its ATS was provided by Japanese company Nippon Signal.[8][7]
Taiwan
editManyTaiwan Railways Administrationtrains are equipped with anEricsson-developed ATS system since the late-1970s (similar to Japanese ATS-SN and ATS-P),[9]which serve as fallback for aBombardier-designedATPsystem introduced in 2006 (equivalent toETCS Level 1), of which the latter system replaced the olderAWSsystem originally introduced in 1978 on theEMU100andEMU200express trains.
United Kingdom
editTheManchester Metrolinkuses ATS equipent betweenTimperleyandAltrincham Interchange.This comprises of electromagnetic beacons before the applicable signal. If a signal is passed at danger, the ATS device inside the tram will apply the track brakes.[10]This system used to be universal along the system, but has been narrowed down to just this section because of recent resignalling to the system.
London Undergroundlines are universally fitted with ATS equipment. This comprises a trip arm just outside the right-hand running rail, and an air valve known as a tripcock on the leading bogie of the train. When the applicable signal shows 'danger', the trip arm is held up by a spring. If a train attempts to pass the signal, the trip arm makes contact with the tripcock. This opens the tripcock, which is connected to the train pipe of the air brakes, and causes an emergency brake application to be made. When the signal shows 'clear', the stop arm is lowered by compressed air.
China
editManyChina Railwaytrunk lines use an ATS system introduced in the late-1980s, similar in principle to Japanese ATS-P and ATC.
See also
editReferences
edit- Richey, Albert S. (1915). "Automatic Train Stop".Electric Railway Handbook.New York: McGraw-Hill. pp.813–815.
automatic train stop.
- ^Union Switch and Signal Co. (1911).Automatic Block Signalling for Interurban Electric Railways.Swissvale, PA. p. 33.
{{cite book}}
:CS1 maint: location missing publisher (link)Bulletin No. 57. - ^"A look at Automatic Train Stop (ATS) – RailPAC".www.railpac.org.2 October 2008.Retrieved15 April2018.
- ^ja: Tự động liệt xa đình chỉ trang trí #1.E5.8F.B7.E5.9E.8BATS
- ^LIRR Atlantic Branch Interlocking Diagrams 1968
- ^"trainsimframework.org".trainsimframework.org.Retrieved15 April2018.
- ^Siemens modernizará las señales de la línea C- EnElSubte, 1 October 2014.
- ^abSánchez, José E. (27 March 2015)."Sistema ATS Línea Roca: Síntesis, Conservación y Evaluación"[Roca Line ATS System: Summary, Conservation, and Evaluation](PDF).ALAF Asociación Latinoamericana de Ferrocarriles(in Spanish).Operadora Ferroviaria Sociedad del Estado.Archived fromthe original(PDF)on 22 March 2016.Retrieved31 August2020.
- ^"South America | NS World wide Projects | NIPPON SIGNAL".www.signal.co.jp.Retrieved2020-08-31.
- ^アジアの thiết đạo 18か quốc ( cát tỉnh thư điếm )
- ^https://www.railengineer.co.uk/signalling-metrolink/
External links
edit- Comprehensive site about the ATS-S(x) system used in Japan
- Comprehensive site about the ATS-Ps system used in Japan