Automatic train stop or ATS is 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 of dead man's switch. Automatic train stop differs from the concept of Automatic Train Control in that ATS usually does not feature an onboard speed control mechanism.
The invention of the fail-safe railway air brake provided an external means for stopping a train via a physical object opening a valve on the brake line to the atmosphere. Eventually known as train stops or trip stops, the first mechanical ATS system was installed in France in 1878 with some railroads in Russia following suit using a similar system in 1880.[ citation needed ] In 1901 Union Switch and Signal Company developed the first North American automatic train stop system for the Boston Elevated Railway. This system was soon adopted by the New York City Subway and other rapid transit systems in the United States. [1]
Mechanical ATS was more popular on rapid transit systems and dedicated commuter rail than 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 of emergency brake applications 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 the Pennsylvania and Long Island Rail Roads installed a mechanical ATS system covering various lines to New York Penn Station using the patented Hall trip valve which was designed to prevent inadvertent activations from debris, however the system was only installed on locomotives and multiple units traveling 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 make use of electric currents or electromagnetic fields to trigger some action in the locomotive 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 was Crocodile (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 the Great Western Railway implemented a similar system in 1906 dubbed Automatic Train Control that served as the template for the magnetic based Automatic Warning System, which ultimately replaced it starting in the 1950s.
In the United States, the General Railway Signal corporation introduced its Intermittent Inductive Automatic Train Stop system in the 1920s which made use of inductive loops in 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 introduced ATS-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-P was used for the first time, and in 1986, H-ATS was invented. [3] [ better source needed ]
The 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 the Interstate Commerce Commission (later the Federal Railroad Administration) as a minimum safety requirement to allow passenger trains to exceed a speed limit of 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 the locomotive engineer to 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 the General Railway Signal company starting in the 1920s and consisted of inductive coils mounted 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 is Intermittent Inductive Automatic Train Stop to differentiate it from mechanical systems being offered at the time. The popularity of ATS as a train protection mechanism fell after the introduction of track coded cab signals in the 1930s.
System | Operator | Lines | In Service | Notes |
---|---|---|---|---|
Train stop | New York City Subway | A Division (IRT) | 1904–present | Trips right |
B Division (BMT and IND) | 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 Fe Chicago to Los Angeles "Super Chief" Route | 1930s-present | Parts of the route have had ATS removed |
Metrolink and Coaster | Former ATSF San Diego Main Line. | ?-present | In service milepost 179 to 249. | |
New York Central | New York to Chicago Water Level Route | 1920s-1971 | Removed by successor Penn Central | |
Southern Railway | 2700 route miles of main line. | 1920s-1971 | Removed in favor of increased CTC use. | |
Union Pacific | Former Chicago & North Western North Line, Northwest Line | 1952–2019 | Used by Union Pacific on lines that also run Metra Commuter trains. Both freight and commuter locomotives must be equipped, with some exceptions. | |
New Jersey Transit | RiverLINE | 2003–present | Installed at interlockings only. Enforces Stop. | |
Westcab | Port Authority of Allegheny County | Pittsburgh Light Rail 42S Line from downtown to South Hills Village. | 1985–present | Some overlap with an Automatic Train Control system installed on the Route 47 Line. |
Many trains in Japan are equipped with this system. The ATS systems in Japan are slightly similar to those used in the United States, but are nowadays primarily transponder-based. The first mechanical ATS systems in Japan were introduced on the Tōkaidō Main Line in 1921, followed by the Tokyo Metro Ginza Line in 1927; but ATS did not become commonplace in the country until the late-1960s as a result of the Mikawashima train crash which occurred in 1962. Below is a list of ATS systems that are specific to Japan only:
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.
In Wellington only a few signals at a converging junction are fitted with mechanical ATS. All electric trains are fitted.
Some Korail and subway lines 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).
Buenos Aires Underground lines and have ATS equipped, while , , and have the more advanced Communications-based train control. [6]
The Roca Line is ATS equipped in its electrified branches since 1985. [7] Its ATS was provided by Japanese company Nippon Signal. [8] [7]
Many Taiwan Railways Administration trains are equipped with an Ericsson-developed ATS system since the late-1970s (similar to Japanese ATS-SN and ATS-P), [9] which serve as fallback for a Bombardier-designed ATP system introduced in 2006 (equivalent to ETCS Level 1), of which the latter system replaced the older AWS system originally introduced in 1978 on the EMU100 and EMU200 express trains.
Some of the Firema T-68 and Bombardier M5000 trams of the Manchester Metrolink trains were equipped with ATS, however this is gradually being phased out due to the introduction of line of sight signalling.
London Underground lines 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.
Many China Railway trunk lines use an ATS system introduced in the late-1980s, similar in principle to Japanese ATS-P and ATC.
A train is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives or railcars, though some are self-propelled, such as multiple units. Passengers and cargo are carried in railroad cars, also known as wagons. Trains are designed to a certain gauge, or distance between rails. Most trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport.
In rail transport, distributed power (DP) is a generic term referring to the physical distribution—at intermediate points throughout the length of a train—of separate motive power groups. Such "groups" may be single units or multiple consists, and are remotely controlled from the leading locomotive. The practice allows locomotives to be placed anywhere within the length of a train when standard multiple-unit (MU) operation is impossible or impractical. DP can be achieved by wireless or wired (trainlined) means. Wired systems now provided by various suppliers use the cabling already extant throughout a train equipped with electronically controlled pneumatic brakes (ECP).
Railway signalling (BE), or railroad signaling (AE), is a system used to control the movement of railway traffic. Trains move on fixed rails, making them uniquely susceptible to collision. This susceptibility is exacerbated by the enormous weight and inertia of a train, which makes it difficult to quickly stop when encountering an obstacle. In the UK, the Regulation of Railways Act 1889 introduced a series of requirements on matters such as the implementation of interlocked block signalling and other safety measures as a direct result of the Armagh rail disaster in that year.
A diesel locomotive is a type of railway locomotive in which the power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels. The most common are diesel-electric locomotives and diesel-hydraulic.
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or gas turbines, are classed as diesel–electric or gas turbine–electric and not as electric locomotives, because the electric generator/motor combination serves only as a power transmission system.
Rail transport terms are a form of technical terminology applied to railways. Although many terms are uniform across different nations and companies, they are by no means universal, with differences often originating from parallel development of rail transport systems in different parts of the world, and in the national origins of the engineers and managers who built the inaugural rail infrastructure. An example is the term railroad, used in North America, and railway, generally used in English-speaking countries outside North America and by the International Union of Railways. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.
A balise is an electronic beacon or transponder placed between the rails of a railway as part of an automatic train protection (ATP) system. The French word balise is used to distinguish these beacons from other kinds of beacons.
Automatic Warning System (AWS) is a railway safety system invented and predominantly used in the United Kingdom. It provides a train driver with an audible indication of whether the next signal they are approaching is clear or at caution. Depending on the upcoming signal state, the AWS will either produce a 'horn' sound, or a 'bell' sound. If the train driver fails to acknowledge a warning indication, an emergency brake application is initiated by the AWS. However if the driver correctly acknowledges the warning indication by pressing an acknowledgement button, then a visual 'sunflower' is displayed to the driver, as a reminder of the warning.
Part of a railway signalling system, a train stop, trip stop or tripcock is a train protection device that automatically stops a train if it attempts to pass a signal when the signal aspect and operating rules prohibit such movement, or if it attempts to pass at an excessive speed.
Cab signaling is a railway safety system that communicates track status and condition information to the cab, crew compartment or driver's compartment of a locomotive, railcar or multiple unit. The information is continually updated giving an easy to read display to the train driver or engine driver.
Automatic train control (ATC) is a general class of train protection systems for railways that involves a speed control mechanism in response to external inputs. For example, a system could effect an emergency brake application if the driver does not react to a signal at danger. ATC systems tend to integrate various cab signalling technologies and they use more granular deceleration patterns in lieu of the rigid stops encountered with the older automatic train stop (ATS) technology. ATC can also be used with automatic train operation (ATO) and is usually considered to be the safety-critical part of a railway system.
Linienzugbeeinflussung is a cab signalling and train protection system used on selected German and Austrian railway lines as well as on the AVE and some commuter rail lines in Spain. The system was mandatory where trains were allowed to exceed speeds of 160 km/h (99 mph) in Germany and 220 km/h (140 mph) in Spain. It is also used on some slower railway and urban rapid transit lines to increase capacity. The German Linienzugbeeinflussung translates to continuous train control, literally: linear train influencing. It is also called linienförmige Zugbeeinflussung.
PZB or Indusi is an intermittent cab signalling system and train protection system used in Germany, Austria, Slovenia, Croatia, Romania, Israel, Serbia, on two lines in Hungary, on the Tyne and Wear Metro in the UK, and formerly on the Trillium Line in Canada.
A train protection system is a railway technical installation to ensure safe operation in the event of human error.
Advanced Civil Speed Enforcement System (ACSES) is a positive train control cab signaling system developed by Alstom. The system is designed to prevent train-to-train collisions, protect against overspeed, and protect work crews with temporary speed restrictions. The information about permanent and temporary speed restrictions is transmitted to the train by transponders (Balises) lying in the track, coded track circuits and digital radio. It was installed beginning in 2000 on all of Amtrak's Northeast Corridor between Washington and Boston, and has been fully active since December 2015, a few months after the 2015 Philadelphia train derailment which it would have prevented.
Pulse code cab signaling is a form of cab signaling technology developed in the United States by the Union Switch and Signal corporation for the Pennsylvania Railroad in the 1920s. The 4-aspect system widely adopted by the PRR and its successor railroads has become the dominant railroad cab signaling system in North America with versions of the technology also being adopted in Europe and rapid transit systems. In its home territory on former PRR successor Conrail owned lines and on railroads operating under the NORAC Rulebook it is known simply as Cab Signaling System or CSS.
Train automatic stopping/stop-position controller (定位置停止装置) (TASC) is the name of a train protection system/automated stopping aid currently used only in Japan. It allows trains equipped with TASC to stop automatically at stations without the need for the train operator to operate the brakes manually, preventing stopping errors and SPADs. TASC is also compatible with automatic train control (ATC) and automatic train operation (ATO), where in the latter case it acts as its auto-braking function.
Anuncio de Señales y Frenado Automático is an Automatic Train Protection system widely deployed on the Spanish rail network. It consists of a mechanism that stops a train if the driver does not properly heed signals.
The intermittent inductive automatic train stop is a train protection system used in North American mainline railroad and rapid transit systems. It makes use of magnetic reluctance to trigger a passing train to take some sort of action. The system was developed in the 1920s by the General Railway Signal Company as an improvement on existing mechanical train stop systems and saw limited adoption before being overtaken by more advanced cab signaling and automatic train control systems. The system remains in use after having been introduced in the 1920s.
Advanced Train Administration and Communications System (ATACS) is an Automatic Train Control (ATC) system developed by RTRI starting from 1995 and first introduced by JR East on the Senseki Line in 2011. It uses radio communication rather than traditional signals, and works as a moving block system.
automatic train stop.
{{cite book}}
: CS1 maint: location missing publisher (link) Bulletin No. 57.