The first 120 series train started the Madrid-Barcelona route on 17th May 2006 under the Alvia commercial brand. This self-propelled train has a rolling system based on the Brava bogies (Self-propelled Variable Gauge System Bogie) developed by CAF, enabling it to provide service on high-speed lines and Iberian gauge branch lines by adapting to each gauge in just three seconds.


Trains in the 120 and 121 series have four carriages. The lighting is a feature that is common to both series and consists of a central ceiling area lit up by halogen light points, while fluorescent tubes along the sides offer indirect light. In addition, each seat has a reading light.

Each compartment also has a luggage area for large or heavy objects, as well as wide luggage racks above the seats all along the compartment.

Passenger lounges have 17-inch TFT monitors that allow viewing of images, videos and additional information about the journey, next stop, train speed, etc. and the seats have individual audio jacks for playing audio in CD and MP3 formats.

Each train carriage has two compartments separated by a vestibule in the middle that is accessed through two outer doors, one on each side of the train. Each door is equipped with a mobile footboard that facilitates access to the vestibule.

The air conditioning consists of a ceiling unit that drives either hot or cold air through ducts at the top of the compartments. The heating is reinforced by additional convectors that emit hot air at foot height in the passenger compartments, vestibules and toilets.

The train seats in the 120 series are distributed in the four carriages so that in the first compartment, which is Clase Preferente (First Class), there are 55 seats in rows of three (2+1). The second carriage has 26 first-class seats, with the same layout, a seat/space for disabled passengers and the buffet car. In the third carriage, there are 76 standard seats, and in the last carriage, another 80 seats in the same class, all with a 2+2 layout.

You access the compartments and also two standard toilets, one on either side, from the vestibules in all carriages, except carriage 2 (first class), which only has one toilet and it is adapted for people with reduced mobility (PMR). All toilets are vacuum toilets and have a bacteriological reactor, so the waste is removed every sixty days.

With the exception of the ones in the first and last row of each compartment, all seats are reclining and adjustable, with armrests with a headphone jack and controls for adjusting volume and selecting channels.

Each carriage has two passenger compartments, one on either side of the vestibule, except the first-class carriage in the middle, which has one compartment and the buffet car.

Clase Turista (Standard class) carriages have double seats for passengers on either side of a central aisle. However, first-class carriages have a row of single seats on one side of the aisle and another of double seats on the opposite side.

The middle first-class carriage has a PMR seat.
The buffet car takes up the same space as a passenger compartment and comes with a proper kitchen, considering all the appliances it contains. From the passenger's perspective, the buffet car looks pleasant, with cosy lighting and two bars, one of which runs along the windows so that you can have your food or drink while looking at the landscape.

Its connecting doors are sliding ones and the outer doors are electrical.

Trains in the 120 series have independent air conditioning in the passenger compartments and in the driver's cab, a public-address and television system, and eight exterior and another eight interior indicators.

This is the layout for the 16 Larga Distancia (Long Distance) trains being delivered between 2007 and 2008, which have 238 seats. The other 29 trains, which will be built for Media Distancia (Mid-distance), will have a different interior layout and features, only one class, and a total of 270 seats.

In September 2001, Renfe awarded the CAF-Alstom consortium a tender for the manufacture of 12 four-carriage trains with a variable-gauge bogie system for serving Alta Velocidad (high-speed) lines and their Iberian-gauge branches. The contract amounted to 115.5 million euros and the first of the twelve units began its on-track testing in early 2005. On 17 May 2006, the first train in the 120 series began running on the Madrid-Barcelona route under the commercial name of Alvia. This self-propelled train has a variable-gauge system that uses BRAVA bogies developed by CAF, enabling it to serve Alta Velocidad (high-speed) lines and Iberian-gauge branches by adapting to each gauge in just three seconds. These new self-propelled, variable-gauge engines have been manufactured by CAF at its Beasaín factory and are high-speed electric trains, capable of running along the two track gauges (Iberian and international) interchangeably, a feature that makes them the first self-propelled trains that can continuously change gauge, without a lot of stopping and starting, making up a loss of fifteen minutes on traditional gauge changes.

The minimum individual composition consists of four engine carriages joined pneumatically, mechanically and electrically. The maximum composition is two train units, i.e. eight carriages.



The structure of the body is self-supporting and has been made using lightweight aluminium alloy. Its design draws on aerodynamic and drive resistance concepts. It has buffer stops on the couplings, deformable structures and anti-climbers to reduce the consequences of a head-on collision for the passengers and for the vehicle itself.

The wall and ceiling lining is made of phenolic resin. The sides are slightly curved, to enhance the aesthetics and are equipped with fixed reflective glass windows. Armoured windows and an anti-shard panes are employed to improve safety whilst in movement. The line of the train is rounded off by skirts and fairings, both at the top and bottom.

The chassis is made from welded steel and the body rests on a load bolster, to which it is tightly fastened and under which the secondary suspension is mounted. Horizontal stresses are transmitted by a drag pivot.

Each unit has two driver's cabs, where the control and driving equipment is located on a dashboard and on a panel on the roof of the cab.
A single platform for each carriage provides access. Two outer doors, on each side, provide access to the platform, while two inner doors provide access to the rooms. Each outer door has a pneumatically operated folding footboard, which facilitates access to platforms of different heights.

Traction and auxiliary systems

The train, in terms of the traction equipment and auxiliary generation is conceived as two half-units. Each one is conceived as a train; therefore, it features all the energy capture, transformation and transmission elements required for the operation of the train. Each unit is autonomous from the capture to the transmission of power to the motors, the generation of low voltage and continuous voltage generation for control equipment.

Each carriage rests on two Brava type A1 bogies, with a single motor axle, meaning there are eight motor axles and eight carrier axles, which mean the gauge change manoeuvre can be performed at a speed of approximately 30 kilometres per hour. Each bogie has two axles, a motor and carrier, and both include brake discs; in addition, the motor is equipped with a gearbox. The motor axle is driven by a drive motor using Cardan-type transmission.

The drive motor, supplied by Alstom, is self-ventilating, asynchronous, features 6 poles and provides 512 kW on axle. The unit has 8 motors, 2 per carriage and each pair of motors is controlled by traction equipment. The IGBT traction converter ensures traction and electric braking, supplying each motor with the necessary power. Electrical braking can act regardless of whether there is voltage in catenary, thanks to the braking rheostats included in each power group.

They feature Caf's Cosmos control and monitoring system, the mission of which is to manage all train operations using different inputs and outputs, whether digital and analogue.
The driver-system interface is visible through a 10-inch TFT screen that graphically displays the status of the train's equipment and allows data and commands to be introduced. It also shows any incidents that occur and provides the driver with recommendations or actions to be taken. Finally, the breakdown log of any equipment connected to the network can be downloaded centrally and remotely. It is also equipped with an anti-slip and anti-lock system.

Compressed air is produced in the two engine cars with driver's cab, using rotary compressors that provide a flow rate of 1,350 l/min. at 10 bar.

The pantograph's lifting equipment is operated pneumatically, with a reserve tank having been conditioned, in case it is needed, and an auxiliary compressor is available in the event of insufficient pressure.

The air-conditioning equipment consists of one compact unit per carriage, providing 50 kW of cooling power and 26 kW of heating power. The system is reinforced by heating convectors on both sides of the passenger compartments and heating resistors for the toilets.

The air-conditioning system features electronic temperature control.
To travel nationwide, it adapts to all the signalling systems currently in use: ASFA 200/98, ASFA AVE and ERTMS.

Bogies and brakes

The bogies are one of the most distinctive elements of the train. All the bogies on the series of carriages are motor bogies and form part of the Brava system (self-propelled variable gauge rolling bogie), developed by Caf; they are mounted on two axles, one carrier and the other motor, which allow the railway vehicles to adapt to any track gauge. This operation is carried whilst in movement at the exchanger, allowing automatic adaptation to Iberian gauge or international gauge tracks in just 3 seconds.

The Brava system consists of two wheelsets that can move laterally, in a pre-defined way, on a non-rotating axle body. During movement, a double safety mechanism prevents the wheels from moving laterally. The wheelbase is achieved as part of a lock-unlock mechanism, automatically operated during the gauge change process.
Furthermore, each bogie is equipped with two sand ejectors, a pneumatic secondary suspension and brake installation, speed and anti-lock sensors, anti-slip shock absorbers and grounding. The bogie on the compartment side also features a tab greasing system, stone trap and an Asfa catcher.

Finally, worth note is the inclusion series of sensors on the bogie, known as the ATMS system, which monitors different parameters, including the temperatures or the conditions of the different mechanical parts of the Brava axis.

These series feature three brake systems:

  • Mixed, recovery and rheostatic electric brake.
  • Pneumatic brake disc.
  • Parking brake.

The electric brake is the priority system, to minimise the use of the pneumatic brake. The pneumatic brake is applied in addition to the electric brake to achieve the required braking effort. In case of emergency braking, only the pneumatic brake reacts, bringing the train to a stop at a maximum distance of 1,000 metres when travelling at 160 km/h, and at 2,700 metres, when travelling at a speed of 250 km/h. The wheels are solid, low-carbon, non-alloy steel with a surface-tempered rim.


The compartment carriages on this train feature Schafenberg automatic couplings with automatic trapdoor for concealment. The type of coupling between carriages is semi-permanent. The system allows 120 series trains to run double length.

Control system

This series has the on-board systems required for the ERTMS level 1 and 2 and ASFA types of signalling, to travel on the two types of lines for which they were designed, and can be adapted to run on other systems, such as LZB and Ebicab.

The 120 and 121 series trains feature the train-to-ground radio communication system and GSM-R, and also come equipped with the Cosmos command and diagnosis system with the TCN communication network.

It also has a system for control and monitoring temperature and acceleration in the bogies.

Technical Features

  • Builder: CAF, with Alstom motor.
  • Units: 12 S-120 (+16 S-120 and 29 S-121).
  • Minimum composition: 4 Mc-M-M-Mc carriages.
  • Gauge : Adaptable Iberian/International.
  • Voltage: 25 kV AC (international) and 3 kV CC (Iberian).
  • Power: 4,000 kW international gauge/2,500 kW Iberian gauge.
  • Engines - model: 8 asynchronous - Alstom MTA/550 H.
  • Converters: 4 with IGTB technology (+3 auxiliary).
  • Maximum commercial speed: 250 km/h international gauge and 220 km/h Iberian gauge.
  • Number of axles: 8 motor axles + 8 carrier axles.
  • Brake: Electric brake, pneumatic brake and park brake.
  • Coupling: Shanfenberg.
  • Driver's cabs: 2.
  • Gauge: 1,435 mm/1,668 mm.
  • Signalling: ASFA, Ertms and Ave.
  • Total seats: S-120: 238 (156 Standard + 81 First + 1 Reduced Mobility). S-121: 281 (280 single class +1 reduced mobility).

Dimensions and Weights

  • Train weight: 247 t.
  • Standard compartment driver carriage's weight: 62 t.
  • Standard middle driver's carriage weight: 59 t.
  • First-class middle driver's carriage weight: 64 t.
  • Weight of Preferente (First Class) driver's cab: 62 t.
  • Total train length: 107.36 m.
  • Length of carriages with driver's compartment: 27.90 m.
  • Length of middle carriages: 25.78 m.
  • Body width: 2.92 m.