HOME

TheInfoList



OR:

Anuncio de Señales y Frenado Automático (ASFA; "Announcement of Signals and Automatic Braking") is an
Automatic Train Protection Automatic train protection (ATP) is the generic term for train protection systems that continually check that the speed of a train is compatible with the permitted speed allowed by signalling, including automatic stop at certain signal aspects ...
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.


Operation

ASFA makes use of
inductive coupling In electrical engineering, two conductors are said to be inductively coupled or magnetically coupled when they are configured in a way such that change in current through one wire induces a voltage across the ends of the other wire through ele ...
between a transceiver on the rolling stock and a
balise 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. Bali ...
(tuned electronic beacon) that oscillates at one of nine preset frequencies when activated by a magnetic field emanating from said transceiver. The balise requires no external power, however, there is a cable for controlling small relays inside the transponder which switch capacitors in/out of the coil circuit and determine which frequency is detected by the passing train. The nine frequencies lie in the 60-100 kHz range (although only five frequencies are used in ASFA) and the wayside balises are mounted between the rails offset from the track centerline to provide directionality. Each balise is protected from debris strikes by a wooden ramp on each side and are typically placed at distances of about 5 and 300 meters before a signal.
The frequency picked up by the transceiver is sent to the driver's cab. In the cab, a light signal is activated and sometimes play a sound that indicates the status of the signal. The train driver must press and release a button within three seconds to acknowledge the signal. Trains passing a signal at "Caution" will receive a speed control indication requiring the train to reduce speed until it passes the 300 meter balise at which point it will be required to reduce speed further or be released to proceed at normal speed. If power is lost the balise defaults to the most restrictive condition. If the signal indicates any reduction in speed, the train must slow down to the required speed limit in time, otherwise the emergency brakes are automatically applied. The emergency braking occurs when a train passes a signal at danger or if a previous balise signal indicates a stop at the next signal and the speed at which the train is travelling is more than that required to stop the train. If an automatic brake application occurs due to a violation of an ASFA signal, the train has to come to a complete halt and a manual reset of the ASFA system in the train must be performed.


Implementation

ASFA is a development of the Westcab intermittent train control technology commercialized by WABCO's Italian subsidiary and licensed to Dimetal of Spain for use on various Iberian rail systems.
RENFE Renfe (, ), officially Renfe-Operadora, is Spain's national state-owned railway company. It was created in 2005 upon the split of the former Spanish National Railway Network (RENFE) into the Administrador de Infraestructuras Ferroviarias ( ...
, the Spanish state-owned railway operator, was put in charge of the rail system in 1975. Before this, the rail networks of other countries had previously deployed similar systems which gave ASFA a technological advantage over its competitors.Railway System Controls, Jan 1975, pp. 20-21 It was progressively rolled out on all of the lines belonging to RENFE beginning with the principal lines and extending to practically the entire Spanish rail network totaling over 13,000 km of track, leaving few lines without ASFA installed. It is also widely deployed on
narrow gauge railway A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge (distance between the rails) narrower than . Most narrow-gauge railways are between and . Since narrow-gauge railways are usually built with Minimum railw ...
s belonging to
FEVE Renfe Cercanías AM, formerly known as Renfe Feve, is a division of state-owned Spanish railway company Renfe Operadora. It operates most of Spain's of metre-gauge railway. This division of Renfe was previously a stand-alone company named F ...
and
Ferrocarrils de la Generalitat Valenciana Ferrocarrils de la Generalitat Valenciana (, "Valencian Government Railways") or FGV is a Valencian Community, Valencian public railway company which operates several lines, in the Autonomous communities of Spain, autonomous community of Valenci ...
. In 2005
Adif ADIF (, an acronym of ) is a Spanish state-owned railway infrastructure manager. This state owned company reports to the Ministry of Transport and Sustainable Mobility. ADIF is charged with the management of most of Spain's railway infrastru ...
, the state-owned Administrator of Rail Infrastructure, began a systemic renewal process which would become known as "ASFA Digital". The changes in the new system do not affect the balises, which continue to transmit their information in analogue form, but rather just the signal processing equipment in the train which once digitalised will allow for the use of braking curves or a better representation of the received signals in the cabin.


Interoperability

The need for interoperability between the rail networks of various countries has caused the
European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...
to consider restricting the use of systems like ASFA which cannot be recognised by trains from foreign countries on the Spanish railway network. Because of this, the
European Train Control System The European Train Control System (ETCS) is a train protection system designed to replace the many incompatible systems used by European railways, and railways outside of Europe. ETCS is the signalling and control component of the European ...
is being progressively phased in. The ETCS has a method of information transmission very similar to ASFA in the Level 1 portion of its specification, but ETCS is more technologically advanced and more secure. Both systems are compatible with each other and can be used on the same line simultaneously.


Types of ASFA

The different types of ASFA are as follows: * ASFA "clásico" ("classic") supports speeds up to 160 km/h (100 mph) * ASFA FAP (version specific to
Ferrocarrils de la Generalitat de Catalunya (, "Catalan Government Railways"; Spanish language, Spanish: ''Ferrocarriles de la Generalidad de Cataluña''), or FGC, is a railway company which operates several unconnected lines in Catalonia, Spain. The lines operated include metro and commu ...
's Línia Llobregat-Anoia) * ASFA 200 supports speeds up to 200 km/h (125 mph) * ASFA 200
AVE is a Latin word, used by the Roman Empire, Romans as a salutation (greeting), salutation and greeting, meaning 'wikt:hail, hail'. It is the singular imperative mood, imperative form of the verb , which meant 'Well-being, to be well'; thus on ...
* ASFA digital


See also

*
Rail transport in Spain Rail transport in Spain operates on four rail gauges and services are operated by a variety of private and public operators. Total railway length in 2020 was 15,489 km (9,953 km electrified). The Spanish high-speed rail network is the longest ...


References

{{DEFAULTSORT:Anuncio de Senales y Frenado Automatico Railway signalling in Spain