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113-468: TVM-300 was developed in the 1970s as part of the TGV project. At speeds faster than 220 kilometres per hour, TGV trains only run along dedicated tracks designated as lignes à grande vitesse (LGV). When travelling at high speed, it is not possible for the driver to accurately see colour-light railway signals at the side of the track. Signalling information is instead transmitted to the train and displayed on

226-620: A "TGV commuter belt" around Paris; the TGV also serves Charles de Gaulle Airport and Lyon–Saint-Exupéry Airport . A visitor attraction in itself, it stops at Disneyland Paris and in southern tourist cities such as Avignon and Aix-en-Provence as well. Brest , Chambéry , Nice , Toulouse and Biarritz are reachable by TGVs running on a mix of LGVs and modernised lines. In 2007, the SNCF generated profits of €1.1 billion (approximately US$ 1.75 billion, £875 million) driven largely by higher margins on

339-721: A Duplex set plus a Reseau set. Each set has a wheelchair accessible compartment. After a lengthy development process starting in 1988 (during which they were known as the TGV-2N) the original batch of 30 was built between 1995 and 1998. Further deliveries started in 2000 with the Duplex fleet now totaling 160 units, making it the backbone of the SNCF TGV-fleet. They weigh 380 tonnes and are 200 m (656 ft 2 in) long, made up of two power cars and eight carriages. Extensive use of aluminum means that they weigh not much more than

452-434: A beacon, at speeds up to 400 kilometres per hour (250 mph). They come in two lengths depending on the line speed, 7 metres and 4.5 metres. These are called BSP ( boucle à saut de phase ) Intermittent Transmission Loops (ITL). They consist of two half loops, which together transmit the message via a 125 kHz frequency, phase shifted with a 62.5 kHz carrier frequency. The information passed along concerns

565-524: A black background and a full stop is indicated as "000" on a red background. Below this display is the speedometer , where the continuously varying target speed is indicated as well as the current speed. Speed is measured by the train's redundant tachometers to a precision of ±2%. The allowable variation between target speed and actual speed is dependent on speed. All the in-cab signalling displays must be very reliable, since they are critical to safety. They have relay-based position sensors which feed back to

678-576: A capacity of 377 seats. They have a top speed of 320 km/h (199 mph). They are 200 m (656 ft 2 in) long and are 2.90 m (9 ft 6 in) wide. The bi-current sets weigh 383 tonnes: owing to axle-load restrictions in Belgium the tri-current sets have a series of modifications, such as the replacement of steel with aluminum and hollow axles, to reduce the weight to under 17 t per axle. Owing to early complaints of uncomfortable pressure changes when entering tunnels at high speed on

791-460: A capacity of 485 seats. They were built with a maximum speed of 300 km/h (186 mph) and 8,800 kW of power under 25 kV. The efficiency of the Atlantique with all seats filled has been calculated at 767 PMPG , though with a typical occupancy of 60% it is about 460 PMPG (a Toyota Prius with three passengers is 144 PMPG). Modified unit 325 set the world speed record in 1990 on

904-443: A desktop computer. Another system, known as VACMA , oversees the driver's alertness. It consists of a foot pedal control that the driver needs to hold down for the TGV to move. This pedal must be released then re-pressed once every 60 seconds if no other activity takes place. There is one period of time before a buzzer sounds, and another period of time before the automatic emergency brakes come on. The control can be released for

1017-759: A distributed Ada database, and object-oriented design. Ada is also used in other air traffic systems, e.g., the UK's next-generation Interim Future Area Control Tools Support (iFACTS) air traffic control system is designed and implemented using SPARK Ada. It is also used in the French TVM in- cab signalling system on the TGV high-speed rail system, and the metro suburban trains in Paris, London, Hong Kong and New York City. Preliminary Ada can be found in ACM Sigplan Notices Vol 14, No 6, June 1979 Ada

1130-451: A driver does not react within 1.5 km (0.93 mi), the system overrides the controls and reduces the train's speed automatically. The TVM safety mechanism enables TGVs using the same line to depart every three minutes. The TGV system itself extends to neighbouring countries, either directly (Italy, Spain, Belgium, Luxembourg and Germany) or through TGV-derivative networks linking France to Switzerland ( Lyria ), to Belgium, Germany and

1243-442: A failure) is interpreted as an indication that the block is occupied. Signalling block boundaries are equipped with electrical separation joints that prevent adjacent blocks from interfering with each other, whilst still letting the traction return current (at 50 Hz) pass through. These tracks circuits are referred as a UM71 C track circuit. The signals which are present in the rail are detected by antennas mounted underneath

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1356-496: A limited form of region-based memory management ; also, creative use of storage pools can provide for a limited form of automatic garbage collection, since destroying a storage pool also destroys all the objects in the pool. A double- dash ("--"), resembling an em dash , denotes comment text. Comments stop at end of line; there is intentionally no way to make a comment span multiple lines, to prevent unclosed comments from accidentally voiding whole sections of source code. Disabling

1469-508: A major publicity campaign focusing on the speed, frequency, reservation policy, normal price, and broad accessibility of the service. This commitment to a democratised TGV service was enhanced in the Mitterrand era with the promotional slogan "Progress means nothing unless it is shared by all". The TGV was considerably faster (in terms of door to door travel time) than normal trains, cars , or aeroplanes . The trains became widely popular,

1582-482: A number of other countries: SNCF and Alstom are investigating new technology that could be used for high-speed transport. The development of TGV trains is being pursued in the form of the Automotrice à grande vitesse (AGV) high-speed multiple unit with motors under each carriage. Investigations are being carried out with the aim of producing trains at the same cost as TGVs with the same safety standards. AGVs of

1695-409: A phase break zone. Just before this section, train operators must power down the motors (allowing the train to coast ), lower the pantograph, adjust a switch to select the appropriate system, and raise the pantograph. Once the train exits the phase break zone and detects the correct electric supply, a dashboard indicator illuminates, and the operator can once again engage the motors. The Sud-Est fleet

1808-427: A power output of 9,600 kW and a top speed of 320 km/h (199 mph). Unlike TGV-A, TGV-R and TGV-D, they have asynchronous motors, and isolation of an individual motor is possible in case of failure. The bi-current TGV 2N2 (Avelia Euroduplex) can be regarded as the 3rd generation of Duplex. The series was commissioned from December 2011 for links to Germany and Switzerland (tri-current trains) and to cope with

1921-426: A powered bogie in the carriages adjacent to the power cars. They are 200 m (656 ft 2 in) long and 2.81 m (9 ft 3 in) wide. They weighed 385 tonnes (849,000 lb) with a power output of 6,450 kW under 25 kV. The sets were originally built to run at 270 km/h (168 mph) but most were upgraded to 300 km/h (186 mph) during mid-life refurbishment in preparation for

2034-519: A programming language generally suitable for the department's and the UK Ministry of Defence 's requirements. After many iterations beginning with an original straw-man proposal the eventual programming language was named Ada. The total number of high-level programming languages in use for such projects fell from over 450 in 1983 to 37 by 1996. HOLWG crafted the Steelman language requirements ,

2147-406: A reference to an instance of a specified type; untyped pointers are not permitted. Special types provided by the language are task types and protected types. For example, a date might be represented as: Important to note: Day_type, Month_type, Year_type, Hours are incompatible types, meaning that for instance the following expression is illegal: The predefined plus-operator can only add values of

2260-649: A series of documents stating the requirements they felt a programming language should satisfy. Many existing languages were formally reviewed, but the team concluded in 1977 that no existing language met the specifications. Requests for proposals for a new programming language were issued and four contractors were hired to develop their proposals under the names of Red ( Intermetrics led by Benjamin Brosgol), Green ( Honeywell , led by Jean Ichbiah ), Blue ( SofTech , led by John Goodenough) and Yellow ( SRI International , led by Jay Spitzen). In April 1978, after public scrutiny,

2373-405: A set of semi-permanently coupled articulated un-powered coaches . Cars are connected with Jacobs bogies , a single bogie shared between the ends of two coaches. The only exception are the end cars, which have a standalone bogie on the side closest to the power car, which is often motorized. Power cars also have two bogies. Trains can be lengthened by coupling two TGVs, using couplers hidden in

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2486-622: A significant business in the defense, aerospace, or related industries, also offered Ada compilers and tools on their platforms; these included Concurrent Computer Corporation , Cray Research, Inc. , Digital Equipment Corporation , Harris Computer Systems , and Siemens Nixdorf Informationssysteme AG . In 1991, the US Department of Defense began to require the use of Ada (the Ada mandate ) for all software, though exceptions to this rule were often granted. The Department of Defense Ada mandate

2599-503: A tasking model that was different from what most real-time programmers were used to. Because of Ada's safety-critical support features, it is now used not only for military applications, but also in commercial projects where a software bug can have severe consequences, e.g., avionics and air traffic control , commercial rockets such as the Ariane 4 and 5 , satellites and other space systems, railway transport and banking. For example,

2712-648: A train's onboard computer system to generate a continuous speed control curve in the event of an emergency brake activation, effectively forcing the driver to reduce speed safely without releasing the brake. TVM-430 is also utilized on the KTX network in South Korea, further enhancing high-speed rail operations in the region. TVM-430 was presented from an intended "modular and flexible" range of signalling system levels from TVM-400 up to TVM-440 (optional automatic train control) and TVM-450 (full driverless control). The line

2825-413: A variable. However, since Ada 2012, functions are not required to be pure and may mutate their suitably declared parameters or the global state. Example: Package specification (example.ads) Package body (example.adb) This program can be compiled, e.g., by using the freely available open-source compiler GNAT , by executing Packages, procedures and functions can nest to any depth, and each can also be

2938-583: A variety of events or actions required: A "black box" similar to an aircraft flight data recorder , passively watches over the entire process, monitoring a variety of parameters and recording the events. In TVM-430-equipped trainsets, older paper-strip recording equipment has been replaced by the ATESS digital recording system. Every action taken by the driver (throttle, brakes, pantographs) as well as signalling aspects (for TVM-430, KVB, and conventional signals) are recorded on magnetic tape for later analysis using

3051-434: A very short period of time before a buzzer sounds, and another very short period of time before the automatic emergency brakes come on. A small amount of over-speed allowance is made before the train's emergency brakes are applied. At speeds below 80 km/h, the allowance is five kilometres per hour. At nominal speeds of 80–160 km/h, the tolerance is ten kilometres per hour and at speeds in excess of 160 km/h, it

3164-424: A whole block of code therefore requires the prefixing of each line (or column) individually with "--". While this clearly denotes disabled code by creating a column of repeated "--" down the page, it also renders the experimental dis/re-enablement of large blocks a more drawn-out process in editors without block commenting support. The semicolon (";") is a statement terminator , and the null or no-operation statement

3277-502: A whole during its early days. Its backers and others predicted that it might become a dominant language for general purpose programming and not only defense-related work. Ichbiah publicly stated that within ten years, only two programming languages would remain: Ada and Lisp . Early Ada compilers struggled to implement the large, complex language, and both compile-time and run-time performance tended to be slow and tools primitive. Compiler vendors expended most of their efforts in passing

3390-576: A ɡʁɑ̃d vitɛs] , "high-speed train"; formerly TurboTrain à Grande Vitesse ) is France's intercity high-speed rail service. With commercial operating speeds of up to 320 km/h (200 mph) on the newer lines, the TGV was conceived at the same period as other technological projects such as the Ariane 1 rocket and Concorde supersonic airliner; sponsored by the Government of France , those funding programmes were known as champion national (" national champion ") policies. In 2023

3503-650: Is null; . A single ; without a statement to terminate is not allowed. Unlike most ISO standards, the Ada language definition (known as the Ada Reference Manual or ARM , or sometimes the Language Reference Manual or LRM ) is free content . Thus, it is a common reference for Ada programmers, not only programmers implementing Ada compilers. Apart from the reference manual, there is also an extensive rationale document which explains

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3616-526: Is 279.3 km/h (173.5 mph). This record was surpassed on 26 December 2009 by the new Wuhan–Guangzhou high-speed railway in China where the fastest scheduled train covered 922 km (573 mi) at an average speed of 312.54 km/h (194.20 mph). A Eurostar (TGV) train broke the record for the longest non-stop high-speed international journey on 17 May 2006 carrying the cast and filmmakers of The Da Vinci Code from London to Cannes for

3729-399: Is a structured , statically typed , imperative , and object-oriented high-level programming language , inspired by Pascal and other languages. It has built-in language support for design by contract (DbC), extremely strong typing , explicit concurrency, tasks, synchronous message passing, protected objects, and non-determinism . Ada improves code safety and maintainability by using

3842-526: Is designed for developing very large software systems. Ada packages can be compiled separately. Ada package specifications (the package interface) can also be compiled separately without the implementation to check for consistency. This makes it possible to detect problems early during the design phase, before implementation starts. A large number of compile-time checks are supported to help avoid bugs that would not be detectable until run-time in some other languages or would require explicit checks to be added to

3955-412: Is divided into signal block sections of about 1,500 metres (~1 mi), the boundaries of which are indicated by blue square signs printed with a yellow-on-white triangle. A digital display on the train driver's dashboard shows the maximum permitted speed for a train's current block, as well as a target speed based on the status of the line ahead. The maximum permitted speed is based on factors such as

4068-462: Is fifteen kilometres per hour. In the centre of the driver's desk in a TGV cab, just below the windscreen, there is a double or triple row of square indicators. This is where target speeds for the current and subsequent blocks are displayed to the driver, in the form of numbers (in kilometres per hour) on a colour-coded background. Full line speed is indicated in black numerals on a green background, while slower aspects are indicated in white numerals on

4181-413: Is high-level and type-safe. Ada has no generic or untyped pointers ; nor does it implicitly declare any pointer type. Instead, all dynamic memory allocation and deallocation must occur via explicitly declared access types . Each access type has an associated storage pool that handles the low-level details of memory management; the programmer can either use the default storage pool or define new ones (this

4294-558: Is linked to the line's centralized traffic control centre, and directly controls about ten blocks of track, each with its own track circuit . Signaling information is encoded in AC signals which are fed into the rails of each block. There are four different carrier frequencies available in TVM-430 and they are used alternately in pairs on both tracks of the TGV line. On one track, blocks use alternately 1,700  Hz and 2,300 Hz, while on

4407-420: Is needed to split carriages, by lifting up cars off a bogie. Once uncoupled, one of the carriage ends is left without support, so a specialized frame is required. SNCF prefers to use power cars instead of electric multiple units because it allows for less electrical equipment. There are six types of TGV equipment in use, all built by Alstom : Retired sets: Several TGV types have broken records, including

4520-474: Is not based on the internal representation of the type but on describing the goal which should be achieved. This allows the compiler to determine a suitable memory size for the type, and to check for violations of the type definition at compile time and run time (i.e., range violations, buffer overruns, type consistency, etc.). Ada supports numerical types defined by a range, modulo types, aggregate types (records and arrays), and enumeration types. Access types define

4633-600: Is one of the more advanced railway signalling systems in the world, although the implementation itself is still based on relays rather than solid state electronics. There are two components to the TVM-430 system: one ground-based, the other on board the train. Both run using Motorola 68020 class processors , and are programmed in Ada , a computer language often used in safety critical systems . The system makes extensive use of redundancy . The ground-based segment of TVM-430 resides in trackside boxes, which control stretches of track about 15 km (9.3 mi) long. Each one

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4746-603: Is particularly relevant for Non-Uniform Memory Access ). It is even possible to declare several different access types that all designate the same type but use different storage pools. Also, the language provides for accessibility checks , both at compile time and at run time, that ensures that an access value cannot outlive the type of the object it points to. Though the semantics of the language allow automatic garbage collection of inaccessible objects, most implementations do not support it by default, as it would cause unpredictable behaviour in real-time systems. Ada does support

4859-402: Is permissive; the driver of a train is permitted to proceed into an occupied block section without first obtaining authorisation. Speed in this situation is limited to 30 kilometres per hour (19 mph) and if speed exceeds 35 km/h (22 mph), the emergency brake is applied and the train stops. If the board marking the entrance to the block section is accompanied by a sign marked Nf,

4972-404: Is structured into standard statements. All standard constructs and deep-level early exit are supported, so the use of the also supported " go to " commands is seldom needed. Among the parts of an Ada program are packages, procedures and functions. Functions differ from procedures in that they must return a value. Function calls cannot be used "as a statement", and their result must be assigned to

5085-492: Is transmitted using phase jumps. The network code is stored in bits 25–27 giving a value between 1–7. Nine-bits contain the network identification code and checksum. The exactly meaning of the remaining 18-bits depends on the particular network code and is known as the "parametrisation". For the first deployment on the LGV Nord , 8-bits are assigned for the speed information, 6-bits for the current block length and 4-bits for

5198-642: Is used only on high-speed lines and in the Channel Tunnel . Outside of the high-speed lines, other signalling systems are used. Every TGV train is equipped with the KVB ( Contrôle Vitesse par Balise , "Beacon Speed Control") which is used throughout the French ligne classique network. In addition to TVM, the following systems are used in various combinations: TGV The TGV ( French: [teʒeve] ; Train à Grande Vitesse , [tʁɛ̃

5311-482: The Cannes Film Festival . The 1,421-kilometre (883 mi) journey took 7 hours 25 minutes on an average speed of 191.6 km/h (119.1 mph). The fastest single long-distance run on the TGV was done by a TGV Réseau train from Calais-Frethun to Marseille (1,067.2 km (663.1 mi)i) in 3 hours 29 minutes at a speed of 306 km/h (190 mph) for the inauguration of

5424-706: The Jacobs bogies . The first Réseau (Network) sets entered service in 1993. Fifty bi-current sets were ordered in 1990, supplemented by 40 tri-current sets in 1992/1993 (adding 3,000 V DC system used on traditional lines in Belgum). Ten tri-current sets carry the Eurostar Red (ex- Thalys ) livery and are known as the PBA (Paris-Brussels-Amsterdam) sets. They are formed of two power cars (8,800 kW under 25 kV – as TGV Atlantique) and eight carriages, giving

5537-550: The LGV Méditerranée on 26 May 2001. On 28 November 2003, the TGV network carried its one billionth passenger, a distant second only to the Shinkansen's five billionth passenger in 2000. Excluding international traffic, the TGV system carried 98 million passengers during 2008, an increase of 8 million (9.1%) on the previous year. All TGV trains have two power cars , one on each end. Between those power cars are

5650-783: The Primary Flight Control System , the fly-by-wire system software in the Boeing 777 , was written in Ada, as were the fly-by-wire systems for the aerodynamically unstable Eurofighter Typhoon , Saab Gripen , Lockheed Martin F-22 Raptor and the DFCS replacement flight control system for the Grumman F-14 Tomcat . The Canadian Automated Air Traffic System was written in 1 million lines of Ada ( SLOC count). It featured advanced distributed processing ,

5763-564: The Shijiazhuang to Zhengzhou segment of China's Shijiazhuang–Wuhan high-speed railway . During the engineering phase, the Transmission Voie-Machine (TVM) cab-signalling technology was developed, as drivers would not be able to see signals along the track-side when trains reach full speed. It allows for a train engaging in an emergency braking to request within seconds all following trains to reduce their speed; if

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5876-560: The US Department of Defense (DoD) became concerned by the number of different programming languages being used for its embedded computer system projects, many of which were obsolete or hardware-dependent, and none of which supported safe modular programming. In 1975, a working group , the High Order Language Working Group (HOLWG), was formed with the intent to reduce this number by finding or creating

5989-1183: The United States Department of Defense (DoD) from 1977 to 1983 to supersede over 450 programming languages used by the DoD at that time. Ada was named after Ada Lovelace (1815–1852), who has been credited as the first computer programmer. Ada was originally designed for embedded and real-time systems. The Ada 95 revision, designed by S. Tucker Taft of Intermetrics between 1992 and 1995, improved support for systems, numerical, financial, and object-oriented programming (OOP). Features of Ada include: strong typing , modular programming mechanisms (packages), run-time checking , parallel processing ( tasks , synchronous message passing , protected objects, and nondeterministic select statements ), exception handling , and generics . Ada 95 added support for object-oriented programming , including dynamic dispatch . The syntax of Ada minimizes choices of ways to perform basic operations, and prefers English keywords (such as "or else" and "and then") to symbols (such as "||" and "&&"). Ada uses

6102-1172: The V150 and TGV 001 . V150 was a specially modified five-car double-deck trainset that reached 574.8 km/h (357.2 mph) under controlled conditions on a test run. It narrowly missed beating the world train speed record of 581 km/h (361 mph). The record-breaking speed is impractical for commercial trains due to motor overcharging, empty train weight, rail and engine wear issues, elimination of all but three coaches, excessive vibration, noise and lack of emergency stopping methods . TGVs travel at up to 320 km/h (199 mph) in commercial use. All TGVs are at least bi-current , which means that they can operate at 25 kV 50 Hz AC (used on LGVs) and 1,500 V DC (used on traditional lines). Trains travelling internationally must accommodate other voltages ( 15 kV  16.7 Hz AC or 3,000 V DC ), requiring tri-current and quad-current TGVs. Each TGV power car has two pantographs: one for AC use and one for DC. When passing between areas with different electric systems (identified by marker boards), trains enter

6215-481: The compiler can in some cases detect potential deadlocks. Compilers also commonly check for misspelled identifiers , visibility of packages, redundant declarations, etc. and can provide warnings and useful suggestions on how to fix the error. Ada also supports run-time checks to protect against access to unallocated memory, buffer overflow errors, range violations, off-by-one errors , array access errors, and other detectable bugs. These checks can be disabled in

6328-628: The compiler to find errors in favor of runtime errors. Ada is an international technical standard , jointly defined by the International Organization for Standardization (ISO), and the International Electrotechnical Commission (IEC). As of May 2023 , the standard, called Ada 2022 informally, is ISO/IEC 8652:2023. Ada was originally designed by a team led by French computer scientist Jean Ichbiah of Honeywell under contract to

6441-676: The Ada-Europe 2012 conference in Stockholm, the Ada Resource Association (ARA) and Ada-Europe announced the completion of the design of the latest version of the Ada language and the submission of the reference manual to the ISO/IEC JTC 1/SC 22 /WG 9 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) for approval. ISO/IEC 8652:2012 (see Ada 2012 RM )

6554-597: The GNAT Compiler is part of the GNU Compiler Collection . Work has continued on improving and updating the technical content of the Ada language. A Technical Corrigendum to Ada 95 was published in October 2001, and a major Amendment, ISO/IEC 8652:1995/Amd 1:2007 was published on March 9, 2007, commonly known as Ada 2005 because work on the new standard was finished that year. At

6667-474: The LGV Atlantique before its opening. Modifications such as improved aerodynamics , larger wheels and improved braking were made to enable speeds of over 500 km/h (311 mph). The set was reduced to two power cars and three carriages to improve the power-to-weight ratio, weighing 250 tonnes. Three carriages, including the bar carriage in the centre, is the minimum possible configuration because of

6780-606: The LGV Atlantique, the Réseau sets are now pressure-sealed. They can be coupled to a Duplex set. The Duplex was built to increase TGV capacity without increasing train length or the number of trains. Each carriage has two levels, with access doors at the lower level taking advantage of low French platforms . A staircase gives access to the upper level, where the gangway between carriages is located. There are 512 seats per set. On busy routes such as Paris-Marseille they are operated in pairs, providing 1,024 seats in two Duplex sets or 800 in

6893-706: The Netherlands (former Thalys ), as well as to the United Kingdom ( Eurostar ). Several future lines are under construction or planned, including extensions within France and to surrounding countries. The Mont d'Ambin Base Tunnel , part of the LGV Lyon–Turin that is currently under construction, is set to become the longest rail tunnel in the world. Cities such as Tours and Le Mans have become part of

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7006-694: The Red and Green proposals passed to the next phase. In May 1979, the Green proposal, designed by Jean Ichbiah at Honeywell, was chosen and given the name Ada—after Augusta Ada King, Countess of Lovelace, usually known as Ada Lovelace . This proposal was influenced by the language LIS that Ichbiah and his group had developed in the 1970s. The preliminary Ada reference manual was published in ACM SIGPLAN Notices in June 1979. The Military Standard reference manual

7119-523: The TGV Réseau sets they supplement. The bi-current power cars provide 8,800 kW, and they have a slightly increased speed of 320 km/h (199 mph). Duplex TGVs run on all of French high-speed lines. TGV POS (Paris-Ostfrankreich-Süddeutschland or Paris-Eastern France-Southern Germany) are used on the LGV Est. They consist of two Duplex power cars with eight TGV Réseau-type carriages, with

7232-432: The TGV network in France carried 122 million passengers. The state-owned SNCF started working on a high-speed rail network in 1966. It presented the project to President Georges Pompidou in 1974 who approved it. Originally designed as turbotrains to be powered by gas turbines , TGV prototypes evolved into electric trains with the 1973 oil crisis . In 1976 the SNCF ordered 87 high-speed trains from Alstom . Following

7345-582: The TGV network. The idea of the TGV was first proposed in the 1960s, after Japan had begun construction of the Shinkansen in 1959. At the time the Government of France favoured new technology, exploring the production of hovercraft and the Aérotrain air-cushion vehicle. Simultaneously, the SNCF began researching high-speed trains on conventional tracks. In 1976, the administration agreed to fund

7458-572: The acceptance of a new standard version, the previous one becomes withdrawn. The other names are just informal ones referencing a certain edition. Other related standards include ISO/IEC 8651 -3:1988 Information processing systems—Computer graphics—Graphical Kernel System (GKS) language bindings—Part 3: Ada . Ada is an ALGOL -like programming language featuring control structures with reserved words such as if , then , else , while , for , and so on. However, Ada also has many data structuring facilities and other abstractions which were not included in

7571-452: The basic arithmetical operators "+", "-", "*", and "/", but avoids using other symbols. Code blocks are delimited by words such as "declare", "begin", and "end", where the "end" (in most cases) is followed by the identifier of the block it closes (e.g., if ... end if , loop ... end loop ). In the case of conditional blocks this avoids a dangling else that could pair with the wrong nested if-expression in other languages like C or Java. Ada

7684-422: The basis of early TGV designs, including the distinctive nose shape of the first power cars. Changing the TGV to electric traction required a significant design overhaul. The first electric prototype, nicknamed Zébulon, was completed in 1974, testing features such as innovative body mounting of motors, pantographs , suspension and braking . Body mounting of motors allowed over 3 tonnes to be eliminated from

7797-503: The block section is not permissive, and the driver must obtain authorisation from the Signalling and Control Centre ( Poste d'Aiguillage et de Régulation ) before entering the block. Once a route is set, or the signalling centre has provided authorisation, a white lamp below the marker board is lit to inform the driver. The driver then acknowledges the authorization using a button on the train's control panel. This temporarily overrides

7910-608: The date of its adoption by ISO. There is also a French translation; DIN translated it into German as DIN 66268 in 1988. Ada 95 , the joint ISO/IEC/ANSI standard ISO/IEC 8652:1995 was published in February 1995, making it the first ISO standard object-oriented programming language. To help with the standard revision and future acceptance, the US Air Force funded the development of the GNAT Compiler . Presently,

8023-602: The emergency braking system, which would otherwise stop the train when proceeding past the non-permissive marker's ground loop. When trains enter or leave the LGV from lignes classiques , they pass over a ground loop which automatically switches the driver's dashboard indicators to the appropriate signalling system. For example, a train leaving the LGV onto a French ligne classique would have its TVM signalling system deactivated and its traditional KVB ( Contrôle Vitesse par Balise , English: beacon speed control) system enabled. It

8136-516: The first line. By the mid-1990s, the trains were so popular that SNCF president Louis Gallois declared that the TGV was "the train that saved French railways". It was originally planned that the TGV, then standing for très grande vitesse ("very high speed") or turbine grande vitesse ("high-speed turbine"), would be propelled by gas turbines , selected for their small size, good power-to-weight ratio and ability to deliver high power over an extended period. The first prototype, TGV 001 ,

8249-432: The first production version was delivered on 25 April 1980. The TGV opened to the public between Paris and Lyon on 27 September 1981. Contrary to its earlier fast services, SNCF intended TGV service for all types of passengers, with the same initial ticket price as trains on the parallel conventional line. To counteract the popular misconception that the TGV would be a premium service for business travellers, SNCF started

8362-476: The front airdam of TGV trains, approximately 1 metre (3 ft) forward of the front axle . These antennas work by inductively coupling to the AC signal shunted between the rails by the first axle. There are four redundant antennas per train, two at each end. Only the two at the "front" of the train (in the direction of travel) are used. The signal from the track circuit is filtered, conditioned, and decoded on board

8475-434: The gradient of the current block: The decoded signal takes the form of a 27-bit digital word, with each bit corresponding to one of the 27 frequencies modulated onto the carrier frequency in the track circuits. The presence of a particular frequency indicates a "1" bit and lack of corresponds to a "0". The resulting word contains several fields, in the following order: These 27 bits of information are used as an input to

8588-528: The inaugural service between Paris and Lyon in 1981 on the LGV Sud-Est , the network, centred on Paris, has expanded to connect major cities across France, including Marseille , Lille , Bordeaux , Strasbourg , Rennes and Montpellier , as well as in neighbouring countries on a combination of high-speed and conventional lines. The success of the first high-speed service led to a rapid development of Lignes à Grande Vitesse (LGVs, "high-speed lines") to

8701-571: The increased traffic due to the opening of the LGV Rhine-Rhone. They are numbered from 800 and are limited to 320 km/h (199 mph). ERTMS makes them compatible to allow access to Spain similar to Dasye . The design that emerged from the process was named TGV M , and in July 2018 SNCF ordered 100 trainsets with deliveries expected to begin in 2024. They are expected to cost €25 million per 8-car set. TGV technology has been adopted in

8814-487: The interest of runtime efficiency, but can often be compiled efficiently. It also includes facilities to help program verification . For these reasons, Ada is sometimes used in critical systems, where any anomaly might lead to very serious consequences, e.g., accidental death, injury or severe financial loss. Examples of systems where Ada is used include avionics , air traffic control , railways , banking, military and space technology . Ada's dynamic memory management

8927-475: The language design and the use of various language constructs. This document is also widely used by programmers. When the language was revised, a new rationale document was written. One notable free software tool that is used by many Ada programmers to aid them in writing Ada source code is the GNAT Programming Studio, and GNAT which is part of the GNU Compiler Collection . In the 1970s

9040-436: The large amount of kinetic energy of a train at high speed, high-speed aerodynamics, and signalling. It was articulated, comprising two adjacent carriages sharing a bogie , allowing free yet controlled motion with respect to one another. It reached 318 km/h (198 mph), which remains the world speed record for a non-electric train. Its interior and exterior were styled by French designer Jacques Cooper, whose work formed

9153-598: The logical outermost block. Each package, procedure or function can have its own declarations of constants, types, variables, and other procedures, functions and packages, which can be declared in any order. A pragma is a compiler directive that conveys information to the compiler to allow specific manipulating of compiled output. Certain pragmas are built into the language, while others are implementation-specific. Examples of common usage of compiler pragmas would be to disable certain features, such as run-time type checking or array subscript boundary checking, or to instruct

9266-690: The massive, language-conformance-testing, government-required Ada Compiler Validation Capability (ACVC) validation suite that was required in another novel feature of the Ada language effort. The first validated Ada implementation was the NYU Ada/Ed translator, certified on April 11, 1983. NYU Ada/Ed is implemented in the high-level set language SETL . Several commercial companies began offering Ada compilers and associated development tools, including Alsys , TeleSoft , DDC-I , Advanced Computer Techniques , Tartan Laboratories , Irvine Compiler , TLD Systems , and Verdix . Computer manufacturers who had

9379-497: The noses of the power cars. The articulated design is advantageous during a derailment, as the passenger carriages are more likely to stay upright and in line with the track. Normal trains could split at couplings and jackknife, as seen in the Eschede train disaster . A disadvantage is that it is difficult to split sets of carriages. While power cars can be removed from trains by standard uncoupling procedures, specialized equipment

9492-460: The onboard signalling computer, thus giving a much more realistic speed profile of continuous acceleration or deceleration for the driver to follow. In addition to the continuous speed control afforded by TVM-430, single instructions can be passed to the train by inductive loops located between the rails, which couple to a corresponding sensor under the train. Using the same frequency encoding principle, 28 bits of information can be recovered from

9605-510: The opening of the LGV Méditerranée. The few sets that kept a maximum speed of 270 km/h (168 mph) operated on routes that include a comparatively short distance on LGV, such as to Switzerland via Dijon; SNCF did not consider it financially worthwhile to upgrade their speed for a marginal reduction in journey time. In December 2019, the trains were phased out from service. In late 2019 and early 2020, TGV 01 (Nicknamed Patrick),

9718-544: The original ALGOL 60 , such as type definitions , records , pointers , enumerations . Such constructs were in part inherited from or inspired by Pascal . A common example of a language's syntax is the Hello world program : (hello.adb) This program can be compiled by using the freely available open source compiler GNAT , by executing Ada's type system is not based on a set of predefined primitive types but allows users to declare their own types. This declaration in turn

9831-460: The other track blocks use alternately 2,000 Hz and 2,600 Hz. Upon these carrier frequencies can be modulated 27 separate audio frequencies, any combination of which can be present at one time; the earlier TVM-300 used eighteen separate frequencies, only one of which could be present at any time. Each block has a receiver at the opposite end to the transmitter, and the loss of the track circuit signal (owing to shorting by train wheels or due to

9944-524: The power cars and greatly reduced the unsprung weight . The prototype travelled almost 1,000,000 km (621,371 mi) during testing. In 1976, the French administration funded the TGV project, and construction of the LGV Sud-Est , the first high-speed line (French: ligne à grande vitesse ), began shortly afterwards. The line was given the designation LN1, Ligne Nouvelle 1 ("New Line 1"). After two pre-production trainsets (nicknamed Patrick and Sophie ) had been tested and substantially modified,

10057-471: The proximity of trains ahead (with steadily decreasing maximum permitted speeds in blocks closer to the rear of the next train), junction placement, speed restrictions, the top speed of the train and distance from the end of LGV route. Trains at high-speed take several kilometres to stop. Since trains will require more than one signal block to slow down, drivers are alerted to reduce speed gradually, several blocks before any required stop. The signalling system

10170-807: The public welcoming fast and practical travel. The Eurostar service began operation in 1994, connecting continental Europe to London via the Channel Tunnel and the LGV Nord-Europe with a version of the TGV designed for use in the tunnel and the United Kingdom. The first phase of the British High Speed 1 line was completed in 2003, the second phase in November 2007. The fastest trains take 2 hours 15 minutes London–Paris and 1 hour 51 minutes London–Brussels. The first twice-daily London-Amsterdam service ran 3 April 2018, and took 3 hours 47 minutes. The TGV (1981)

10283-559: The same length as TGVs could have up to 450 seats. The target speed is 360 kilometres per hour (224 mph). The prototype AGV was unveiled by Alstom on 5 February 2008. Italian operator NTV is the first customer for the AGV, and became the first open-access high-speed rail operator in Europe, starting operation in 2011. The design process of the next generation of TGVs began in 2016 when SNCF and Alstom signed an agreement to jointly develop

10396-402: The same type, so the expression is illegal. Types can be refined by declaring subtypes : Types can have modifiers such as limited, abstract, private etc. Private types do not show their inner structure; objects of limited types cannot be copied. Ada 95 adds further features for object-oriented extension of types. Ada is a structured programming language, meaning that the flow of control

10509-401: The signalling computer the current aspect being displayed to the driver. If there is a failure in the display unit, appropriate action is taken to stop the train. In order to reduce stress on the driver, speeds are displayed over several blocks ahead of the train. When a block is followed by a more restrictive (slower) block, the display for that block flashes so the driver can better anticipate

10622-402: The source code. For example, the syntax requires explicitly named closing of blocks to prevent errors due to mismatched end tokens. The adherence to strong typing allows detecting many common software errors (wrong parameters, range violations, invalid references, mismatched types, etc.) either during compile-time, or otherwise during run-time. As concurrency is part of the language specification,

10735-428: The south ( Rhône-Alpes , Méditerranée , Nîmes–Montpellier ), west ( Atlantique , Bretagne-Pays de la Loire , Sud Europe Atlantique ), north ( Nord , Interconnexion Est ) and east ( Rhin-Rhône , Est ). Since it was launched, the TGV has not recorded a single passenger fatality in an accident on normal, high-speed service. A specially modified TGV high-speed train known as Project V150 , weighing only 265 tonnes, set

10848-420: The speed change without releasing the brake. Restrictive indications can only be updated at block boundaries, except in emergencies. They are accompanied by an audible in-cab horn signal. Restrictions can however be lifted at any time within a block. TVM-430 has extensive redundancy built into it, and one might wonder why it is not used to control the train directly. However, in view of the lack of adaptability of

10961-838: The system to unexpected situations, it is considered desirable to retain a human in the loop. Driving a TGV is therefore done entirely manually, but the signalling system keeps a very close watch to ensure maximum safety. (Stop, track section is occupied or end of line) (Avertissement 0; stop at next signal) (Exécution 80; do not exceed 80 km/h) (Avertissement 80, speed change to 80 km/h ahead) (Exécution 160, do not exceed 160 km/h) (Avertissement 160; speed change to 160 km/h ahead) (Exécution 220; do not exceed 220 km/h) (Avertissement 220; speed change to 220 km/h ahead) (Voie Libre 270 km/h; proceed at 270 km/h) (Avertissement 270; speed change to 270 km/h ahead) (Voie Libre 300 km/h; proceed at 300 km/h) The TVM system

11074-503: The track-circuit function and for the activation of relays within the train TVM430 equipment. The data bits themselves are frequency modulated at 0.64 Hz intervals between 0.88 Hz and 17.52 Hz. Intermittent signal At fixed locations cable loops are used between the tracks. A reference signal of 62.5 kHz is transmitted, along with two 125 kHz carrier frequencies, out-of-phase with each other. A 4,800-baud message

11187-412: The train by two redundant digital signal processors. Continuous signal For the continuous signal an analogue bandpass filter is applied to isolate the range of TVM frequencies between 1,600–2,640 Hz. Within this, each of the four 1,700/2,000/2,300/2,600 Hz carrier-frequencies are tested for the presence of a frequency-modulated 25.68 Hz signal. The 25.68 Hz signal is necessary for

11300-472: The train driver's dashboard. The driver is shown the safe operating speed, measured in kilometres per hour . The 1980s-developed TVM-430 system provides more information than traditional signalling systems would allow, including track gradient profiles and information about the state of signalling blocks further ahead. This high degree of automation does not remove the train from driver control, although there are special safety mechanisms that can safely bring

11413-465: The train to a stop in the event of driver error. The TVM system was developed by the French group Compagnie de Signaux et d'Entreprises Electriques (CSEE), now part of Hitachi Rail STS . Two versions of TVM signalling, TVM-430 and TVM-300, are in use on the LGV. TVM-430, a newer system, was first installed on the LGV Nord to the Channel Tunnel and Belgium, and supplies trains with more information than TVM-300. Amongst other benefits, TVM-430 allows

11526-456: The train's signalling computer, the onboard part of the TVM-430 system. In older versions of TVM, the target speed was updated only at every block boundary, resulting in a "staircase" style speed profile which is not representative of the continuous speed changes effected by the driver. However, with the additional information of block length and profile, TVM-430 is able to generate a continuously varying target speed through calculations performed in

11639-416: The trainsets, with goals of reducing purchase and operating costs, as well as improved interior design. In June 2021, there were approximately 2,800 km (1,740 mi) of Lignes à Grande Vitesse (LGV), with four additional line sections under construction. The current lines and those under construction can be grouped into four routes radiating from Paris. Ada programming language Ada

11752-532: The very first TGV train, did a farewell service that included all three liveries that were worn during their service. The 105 train Atlantique fleet was built between 1988 and 1992 for the opening of the LGV Atlantique and entry into service began in 1989. They are all bi-current, 237.5 m (779 ft 2 in) long and 2.9 m (9 ft 6 in) wide. They weigh 444 tonnes (979,000 lb) and are made up of two power cars and ten carriages with

11865-535: The world record for the fastest wheeled train, reaching 574.8 km/h (357.2 mph) during a test run on 3 April 2007. In 2007, the world's fastest scheduled rail journey was a start-to-stop average speed of 279.4 km/h (173.6 mph) between the Gare de Champagne-Ardenne and Gare de Lorraine on the LGV Est , not surpassed until the 2013 reported average of 283.7 km/h (176.3 mph) express service on

11978-410: Was approved on December 10, 1980 (Ada Lovelace's birthday), and given the number MIL-STD-1815 in honor of Ada Lovelace's birth year. In 1981, Tony Hoare took advantage of his Turing Award speech to criticize Ada for being overly complex and hence unreliable, but subsequently seemed to recant in the foreword he wrote for an Ada textbook. Ada attracted much attention from the programming community as

12091-496: Was boosted to 31 kV, and extra ballast was tamped onto the permanent way. The train beat the 1990 world speed record of 515.3 km/h (320.2 mph), set by a similarly TGV, along with unofficial records set during weeks preceding the official record run. The test was part of an extensive research programme by Alstom. In 2007, the TGV was the world's fastest conventional scheduled train : one journey's average start-to-stop speed from Champagne-Ardenne Station to Lorraine Station

12204-588: Was built between 1978 and 1988 and operated the first TGV service, from Paris to Lyon in 1981. There were 107 passenger sets, of which nine are tri-current (including 15 kV  16.7 Hz AC for use in Switzerland) and the rest bi-current. There were seven bi-current half-sets without seats that carried mail for La Poste between Paris, Lyon and Provence , in a distinctive yellow livery until they were phased out in 2015. Each set were made up of two power cars and eight carriages (capacity 345 seats), including

12317-538: Was effectively removed in 1997, as the DoD began to embrace commercial off-the-shelf (COTS) technology. Similar requirements existed in other NATO countries: Ada was required for NATO systems involving command and control and other functions, and Ada was the mandated or preferred language for defense-related applications in countries such as Sweden, Germany, and Canada. By the late 1980s and early 1990s, Ada compilers had improved in performance, but there were still barriers to fully exploiting Ada's abilities, including

12430-428: Was first published in 1980 as an ANSI standard ANSI/ MIL-STD 1815 . As this very first version held many errors and inconsistencies , the revised edition was published in 1983 as ANSI/MIL-STD 1815A. Without any further changes, it became an ISO standard in 1987. This version of the language is commonly known as Ada 83 , from the date of its adoption by ANSI, but is sometimes referred to also as Ada 87 , from

12543-530: Was published in December 2012, known as Ada 2012 . A technical corrigendum, ISO/IEC 8652:2012/COR 1:2016, was published (see RM 2012 with TC 1 ). On May 2, 2023, the Ada community saw the formal approval of publication of the Ada ;2022 edition of the programming language standard. Despite the names Ada 83, 95 etc., legally there is only one Ada standard, the one of the last ISO/IEC standard: with

12656-427: Was the only gas-turbine TGV: following the increase in the price of oil during the 1973 energy crisis , gas turbines were deemed uneconomic and the project turned to electricity from overhead lines , generated by new nuclear power stations . TGV 001 was not a wasted prototype: its gas turbine was only one of its many new technologies for high-speed rail travel. It also tested high-speed brakes, needed to dissipate

12769-455: Was the world's second commercial and the fastest standard gauge high-speed train service, after Japan's Shinkansen , which connected Tokyo and Osaka from 1 October 1964. It was a commercial success. A TGV test train holds the world speed record for conventional trains. On 3 April 2007 a modified TGV POS train reached 574.8 km/h (357.2 mph) under test conditions on the LGV Est between Paris and Strasbourg. The line voltage

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