Rolling stock • Block train • High speed train • Alstom • Avelia Horizon
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In brief
The high-speed passenger train in the Avelia Horizon range is an Alstom design, but was clearly conceived on the basis of the needs and criteria of the French public operator SNCF, in particular through its double-decker architecture and keeping the concept of two power cars at each end of the trainset. It was also ordered by the French private operator Proxima. However, this train is intended for export to Europe and the rest of the world, with a modular design that allows the choice of a single-decker trainset, for example.
Since 1981 in France, the TGV has been revolutionising the history of the railways. The TGV Avelia Horizon was due to be delivered to the SNCF at the end of 2024 / beginning of 2025, bringing a series of innovations, under the name of TGV Inoui. Originally, they were due to be operational for the Paris Olympic Games, but the delivery schedule was severely disrupted by the 2020 pandemic. Modular, the first trainsets will be used mainly to serve the south-east of France, Paris-Lyon-Marseille-Nice.
According to the SNCF and Alstom, this new generation of trains has come very close, the new interior features 400 different changes compared with the previous generation. The design is the result of a collaboration between the SNCF’s in-house design agency, Arep, and the Japanese studio Nendo.
Including the recent tranche of 15 trains for international services, 115 TGV M trains have now been ordered. It’s a sign of the times that speed is not the main concern for Alstom’s engineers. The real innovation is energy savings. The TGV-M consumes 20% less electricity while accommodating 100 additional passengers, thereby improving the carbon footprint of its passengers.
Family name: Avelia Horizon
Class: Depends on the owner
Manufacturer(s): Alstom
Train type: Trainsets
Sector: Passengers transport
Type of service: Main line
Operator(s): SNCF (115), Proxima (12), ONCF (18)
First services: SNCF 2026, Proxima …
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Train length: Up to 202m
Maximum speed: 320 km/h
Traction system: Alstom IGBT–VVVFPower output8 MW
Electric system(s): 25 kV 50 Hz AC, 15 kV 16.7 Hz AC, 1,500 V DC, 3,000 V DC
Pantograph:, 2 per power car
Braking system(s): Dynamic and Regenerative brake
Track gauge: 1,435 mm
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Formation: SNCF, Proxima: 2 power cars + 7 to 9 cars
Seats first class: to be determined
Seat second class: to be determined
Restaurant car: no
Bar car: yes
Total seats: to be determined
Several innovations mark a turning point in TGV design, such as a revolutionary element that houses an unprecedented energy storage device. These technological advances have evolved over a decade, from the initial concept of the TGV-M to practical trials on the French rail network in 2023.
The definition of a high-speed train varies by region, but generally, it refers to trains that operate at speeds of at least 250 km/h (155 mph) on newly built lines and 200 km/h (124 mph) on upgraded lines. In Europe, for example, the UIC (International Union of Railways) considers a commercial speed of 250 km/h as the principal criterion for high-speed rail. In the United States, the definition can include trains operating at speeds ranging from 180 km/h (110 mph) to 240 km/h (150 mph).
➤ See the UIC definition
Customers on this train
SNCF Voyageurs
2026 – …
Proxima
2028 – …
ONCF
2030 – …
Background and development
In 2015, SNCF launched a tender and selection program to find a partner for designing a new generation of high-speed trains through an “innovation partnership.” On September 7, 2016, SNCF and Alstom signed an agreement to develop and manufacture these trains. The design phase was scheduled to be completed by the end of 2017, with the trains expected to enter service in 2022. SNCF set clear objectives: the new trains needed to be at least 20% cheaper to purchase, have lower operational costs, consume 20% less energy, and accommodate more passengers than the TGV Duplex.
To achieve these goals, Alstom streamlined production costs by utilizing standardized components from its Avelia range, a line intended for international sales. This marked a departure from SNCF’s usual practice of commissioning custom-designed TGVs, which increased costs due to bespoke engineering requirements.
By July 2018, with the design finalized, the new model was officially named Avelia Horizon. SNCF placed an order for 100 trainsets at a cost of 2.7 billion euros. Production was set to begin in autumn 2019, with initial tests scheduled for summer 2021 and the first deliveries expected in 2023. The full delivery process would extend until 2033, with the possibility of additional orders. In August 2022, SNCF exercised an option for 15 more trainsets, bringing the total order to 115 units, with deliveries planned until 2036.
In July 2020, Alstom unveiled the first shell of the new TGV, set to be ready for the 2024 Paris Olympics, but this date was never reached due to delivery delays and complex development work. In 2023, testing campaigns took place across France. By 2024, Proxima and Morocco’s national railway signed agreements to acquire additional trainsets, ensuring a long-term future for this high-speed innovation. In March 2025, SNCF finally presented a complete, fully finished trainset, complete with interior design.
The specifications in detail
As we all know, the post-pandemic geopolitical and economic situation has reinvigorated the concept of national industry in every country in the world. That’s why you’ll be hearing a lot about France in the design of the Avelia Horizon TGV.
This new generation of TGVs stands in stark contrast to its predecessors, with a number of strong choices. All the design work was carried out by Arcep, Arep, a subsidiary of SNCF Gare et connection. They worked in partnership with the Japanese agency Nendo Naddeo.
For this fifth generation of the TGV (name registered by SNCF Voyageurs), the teams have started from scratch, but have drawn on the experience of the four previous generations. In total, more than 2,000 people have worked to make this project a success.
At equivalent performance levels, this new generation of TGV will be 20% more energy-efficient, thanks in particular to its aerodynamic design. It will also reduce CO2 emissions by 50% compared with single-decker high-speed trains. Made from 25% recycled materials (100 tonnes), it will be 97% recyclable, making it the high-speed train with the lowest carbon footprint on the market.
Alstom’s industrial innovations
Ten of the sixteen Alstom sites in France are involved in the design of the new train: Belfort for the power cars, La Rochelle for the carriages (studies, industrialization, purchasing, manufacturing and testing of passenger carriages), logistical and service support, and project management; Villeurbanne for the computerized control and command system, passenger information and on-board equipment; Ornans for the engines; Le Creusot for the bogies; Tarbes for traction; Toulouse (COE electrical) for the electrical circuits; Petit Quevilly for the transformers; Saint-Ouen for design, signalling, and Valenciennes for the study of the interior design elements. In total, 4,000 jobs will be generated by this project in the French rail industry.
To carry out the industrial innovations linked to this new TGV project, Alstom has set up unprecedented industrial processes:
• At Alstom’s Belfort site, a new single, multi-purpose line dedicated to the TGV power train has been created. This single line makes it possible to rationalise the footprint of the manufacturing facilities by reducing it by 6,000 m2, automatically leading to a reduction in electricity and associated heating consumption.
• At Alstom’s La Rochelle site, the creation of a new assembly line for passenger carriages. This is a model production line for the rail industry, driven by continuous improvement, which has resulted in greater efficiency, simplified assembly, improved operator safety and more ergonomic workstations.
This manufacture line also makes it possible to rationalise the footprint of the manufacturing facilities and reduce the associated electricity and heating consumption. An office area for support functions (engineering, industrialisation, supply chain, etc.) has also been created as close as possible to the assembly line.
In addition, Alstom recently announced its intention to invest €10 million in the construction of a new building at Belfort. With a length of 250 metres, this new building will increase the site’s industrial capacity for preparing high-speed trainsets for commercial service. It will be able to accommodate a complete TGV trainset.
In May 2021, Alstom unveiled the front end of the first power train at its Belfort plant. A great deal of work has been carried out on the aerodynamics, with a much more streamlined power train than hitherto. Work has also been carried out on the fairing of all the equipment, while the motorization section is much more simplified than on previous generations.
A solution in case of breakdown
The batteries-pack (called “greffon” in french) is an innovative back-up system that enables the train to continue running even if its main power supply fails. The system is based on emergency batteries installed on board the train. In the event of a power failure, these batteries take over to supply the energy needed to keep the train running. They generally enable the train to run to the nearest station, where repairs or an external power supply can be installed.
The main advantage of this system is to avoid situations where a train is immobilized on the track while waiting for assistance. The graft will keep traffic flowing, even in the event of a breakdown. This system only concerns the train. It is of course inoperative in the event of track disturbances, such as signal failures or human intrusion.
Modularity
The TGV-M’s strength lies in its modularity, which makes it possible to adjust the number of cars as closely as possible to the market’s needs (7, 8 or 9), to quickly transform a 1st class space into a 2nd class space and vice versa, to reconfigure the interior by removing or adding seats, bicycle or luggage spaces, etc. Each operator will be able to choose the interior and design they want, because this TGV from the Avelia Horizon range is a product designed for sale, not just an idea from SNCF, Alstom’s first customer.
The simplification of the TGV’s historic electrical architecture, combined with smaller electrical equipment, has made it possible to house all the equipment in 2 mini-motors, facilitating the addition of this ninth car.
A long testing period
In December 2022, the first TGV M test train has been at the Velim test site in the Czech Republic. This test campaign lasted almost 6 months and was a crucial phase in a series of trials for the next generation of high-speed trains.
- Static and Quasi-Static Tests:
Each component was evaluated separately before assembly to verify performance and durability. The train was then tested at Alstom’s Bellevue site at standstill and at speeds up to 30 km/h to ensure proper integration and interaction of all onboard systems. - Pre-Validation Tests:
Conducted at the Velim test site, these tests occur in a controlled environment, free from commercial traffic. The goal is to validate the train’s overall functionality, address design risks, and refine digital models. Speeds gradually increase to 200 km/h before transitioning to the French national network, where tests reach 320 km/h. - Admission Tests:
These trials simulate real-world scenarios, including adverse weather and operational disruptions. Conducted by an accredited organization, they are essential for obtaining Commercial Service Authorization from the European Railways Agency (ERA). - Endurance Tests:
Prior to commercial launch, multiple trainsets will run extensive routes across France, ensuring long-term reliability. SNCF Voyageurs personnel will also use this phase to familiarize themselves with the train’s new features.
At the Velim site, initial tests saw the TGV M reach 200 km/h within a week—exceeding expectations. Ongoing tests include braking, pantograph performance, and signaling. Future trials in Vienna will assess energy efficiency, with simulations covering extreme temperatures (-20°C to +40°C) and wind speeds up to 160 km/h. These efforts contribute to a targeted 20% reduction in energy consumption.
Pre-validation tests continued in Vienna, where climatic tests assessed the train’s behavior at extreme temperatures. In June 2023, testing continued in France, with the support of train drivers, expert rolling stock engineers from SNCF Voyageurs, specialists from Alstom and others.
A rolling stock engineering team from SNCF Voyageurs managed the test phases in France, mobilizing more than 250 of its 1,800 technicians and engineers to the project. Speed was to reach 320 km/h, the maximum speed authorized for commercial operation on high-speed lines.
The performance of the TGV M will be evaluated on the French rail network under real operating conditions. Acceptance tests, carried out in the first half of 2024, were aimed at reaching 320 km/h. The European Union Railway Agency (ERA) will now issue the marketing authorization for the INOUI TGV.
In autumn 2024, several production units were put into service to test the train’s reliability and functionality in real-life conditions. This phase also enabled SNCF drivers and conductors to familiarize themselves with the train. Before its entry into service, SNCF’s TGV INOUI will have undergone 350 weeks and 1 million kilometers of testing. Alstom is now in a position to sell its product. 🟧
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