Sistema Controllo Marcia Treno

Sistema di Controllo della Marcia del Treno (abbr. SCMT ) is a train control and train protection system, which is used in the RFI network in Italy. It can run under ETCS Level 1 and use eurobalises for data transmission between track and train. It consists of the subsystems " SST " ( Sottosistema di Terra = " trackside subsystem " or wayside equipment ) and " SSB " ( Sottosistema di Bordo = " -vehicle subsystem " or vehicle equipment). The names SST and SSB are from the EU regulations for interoperability.

Overview SCMT on-board equipment

The Italian SCMT can be used as the sole national train control and train protection system. The European ETCS enables the integration of national systems, so that the SCMT can be active as a national system under ETCS.

The SCMT - board equipment consists essentially of the following components:

  • Antennas for the detection of Balise telegrams
  • Antennas to capture the continuous feedback signal (RSC, Ripetizione Segnali Continua )
  • An odometry means for detecting the distance traveled,
  • Two main computer for the train control and assurance ( RSC) and the Control (CMT )
  • Display and operating unit on the driver's desk
  • Intervention in the train control to initiate the emergency brakes.
  • Braking action group for controlling an emergency brake

SCMT integrates two different control systems: RSC ( Ripetizione Segnali Continua, train control and assurance ) and CMT ( Controllo Marcia Treno, Zugsgteuerung ). Depending on the operating mode, which must match the respective wayside equipment, the two systems can work individually or also act complementarily. RSC is the older system. Meanwhile, all RSC routes have been additionally equipped with SCMT beacons, so that work together in this case both systems.

The task of automatic train control systems is the calculation and monitoring of allowable speeds on top of each route traveled. This is usually done by means of sensor technology and track detection technology in a vehicle ( "local" )

The task of train control systems is to ensure that all trains running on a track, hold each other a sufficient distance ( block sections and driving licenses that are granted to it or not. ) This control is usually done on the car service centers or with operating centers.

The task of train control system is the best possible way to reconcile the two together to relieve the driver as much as possible.

The excess of a train of the current speed speed eg at 3 km / h and 5 km / h, the system initiates an emergency brake.

Through the detailed information that is transmitted, and the precise monitoring of the schedule can control the system if the train the currently permitted speed and the braking curves comply - speeding or unauthorized driving past stop signals should therefore be impossible.

RSC - vehicle equipment

The " Ripetizione Segnali Continua a 9 codici " (continuous signal feedback signal with 9 terms ), or " RSC 9 Codici " ( RSC9 ) is an extension of the formerly used in Italy RSC with 4 signal aspects see RSC 4 Codici ); it can be received and distinguished several different codes from the track. With active RSC system ( RSC button will light blue ) are shown on the screen of the control and display unit, the corresponding code symbols. The icon for the received code is highlighted.

The RSC system is calculated, depending on the received code, the speed limit for the current block, taking account of train data entered.

CMT- vehicle equipment

The " Controllo della Marcia del Treno " ( Zugfahrtsteuerung ) in SCMT monitors the respective permissible speed of the train. Calculations are based on the received route data and train data entered by the train driver. A distinction is made between two types of speed limits: First permissible constant speed and 2 reduction in the maximum speed.

To avoid jumps in the velocity curves at a required speed reduction curve is calculated on a target point on the route to the lower speed. Higher speed limits are effective immediately.

The permissible velocity is calculated for different levels:

  • For the rank of the train ( " Rango " )
  • For the rank of the track ( " grado " )
  • For day time limits
  • For speed restrictions
  • For the case of passivated train control systems
  • For the passage of branching points
  • For approaching content displayed signals

The SCMT operator panel provides the drivers, except for the activity of the CMT system ( SCMT button lights up blue), No ads.

RSC - track equipment

The RSC codes are transmitted by modulated alternating voltages across the tracks. The tracks are divided into blocks (usually 1350 m, but there are also shorter and longer blocks possible), and each block sends a code. Course areas can not encode itself.

The following codes can be transferred:

  • No code ( behind stop signals, in the turnout area, occupied blocks)
  • Announcement of a halt displayed signal ( at the end of block )
  • Before displaying a main signal, driving with a Weichenabzweigung of 30 km / h or 60 km / h
  • Before displaying a main signal, driving with a Weichenabzweigung of 100 km / h
  • Code is not used
  • If the distance from the end of the block to stop pointing signal is less than 2700 m and the next sub-block has the code 75
  • Announcement of a non-coded route section
  • Notice of speed restrictions and within speed restrictions
  • If the distance from the end of the block to stop pointing signal is less than 2700 m and the next sub-block has the code 180
  • Free range for at least 2700 m ( 2 blocks)
  • Free range for at least 4050 m ( 3 blocks)
  • Free range for at least 5400 m ( 4 blocks)

SCMT wayside equipment

Route data that needs the SCMT - vehicle equipment for calculating the allowable current speed of the train, she receives beacons. The beacons are mounted centrally on the track and send a data telegram to the train when he runs over. The train must be equipped with appropriate antennas.

The beacons are arranged in groups. In the control groups from two beacons can be used, but four groups is permitted. Each group contains a unique ID in the message. The beacons of a group have a distance of 3 to 7 m.

The tracks are equipped for both directions with beacons. A numbering of Balise telegrams within each group, allows the detection of the direction for which the data are intended. Telegrams with ascending numbering to be used for the direction of travel.

Bali Seng supporters groups are linked to each other, that is, last received telegram the next group is announced. This can be done over the distance to the next group or the type of the next group. When you miss an announced balise group, the CMT system take different measures, among others, an emergency brake.

There are so-called fixed beacons (also: Festdatenbalisen ), which always send the same telegram, and switchable beacons (also: transparent beacons ) which can send several different messages, eg, depending on the signal state.

In addition, there are also mobile beacons, secure the speed restrictions.

For the SCMT wayside equipment 9 different message types are defined. Each message consists of a header, the message type itself and the data part. Some data are included in several message types.


The equipment with SCMT is completed on the entire main and feeder network ( rete fondamentale e complementare ). This also applies for retrofitting the locomotives. An extension on the remaining branch lines ( rete secondaria ) is not planned, there is a much simpler and pure Train Control ( SSC, Sistema Supporto Condotta ) apply.

With the exception of RSC 4 Codici - whose emphasis is less on the control of the train than on the continuous cab signaling system - it existed before the SCMT in Italy no train control system, the monitored signal attention. Meanwhile entire Italian railway network is fully equipped with automatic train control systems. At 31.12.2013 11,848 km with SCMT, 4273 km with SSC were (of which 221 km twice with SSC SCMT ) and 654 km equipped with ERTMS.