Radio-based train control system (RBTC)

RBTC — COMPONENTS AND ADVANTAGES: reliability, safety and efficiency

Radio Based Train Control System (RBTC) improves the efficiency of railways by increasing traffic capacity, cutting operational and energy consumption costs and reducing wear out of tracks and rolling stocks.

The system implements traffic control functions and provides safety at stations and open lines due to continuous data exchange between trains and the radio-block center, which receives the information from trains on their current location and transmits permissible traffic parameters to the onboard systems. 

RBTC COMPONENTS 

The RBTC system consists of a station part and complex onboard systems installed on locomotives – systems of traffic control and management, data exchange via a radio channel, train location, velocity, and distance covered measurement, traffic parameter, and braking velocity curve calculation, train integrity, etc. 

Radio block center plays a key role in the RBTC system by controlling the current traffic situation and giving line clearance permissions depending on the location and speed of the train ahead and other parameters. It is closely integrated with the CBI central processor and is built on the same hardware platform.

Data exchange between the radio block center (Traffic Control Center, TCC) and the train is performed via digital radio network base stations that are positioned in a way that provides double lapping of the radio signal along the whole line. RBTC allows applying different radio connection digital systems that allow taking into consideration the peculiarities of a particular railway. In particular, projects in Kazakhstan and in Mongolia support data exchange between the train and radio block center via a radio network of a TETRA standard.

For RBTC operation with moving blocks on open lines the installation of only passive balises is sufficient. The data is read off balises with the help of onboard radio aerial when the train is passing by and serves for correcting errors that occurred when measuring the covered distance with onboard locomotive systems.

Onboard RBTC safety system on locomotives comprises a processor module, speed and distance covered  modules, interface with locomotive equipment, receiving and radio aerial modules for receiving information from balises, a speed sensor, and the driver’s display, as well as a radio modem, GPS antennae and a radio channel. 

Onboard equipment also comprises two half-sets of train integrity device systems, one of which is installed on the tail car. They continuously control the pressure in the brake conduit and if it drops below the set level they initiate sending the alarm signal to the radio block center. 

KEY ADVANTAGES

Video: RBTC

KEY FEATURES

The RBTC system uses the principle of moving block sections to increase the traffic capacity of railway lines. The train spacing is based on the actual speed of each train and their speed over each other. Unlike the traditional automatic line block signaling system, the principle of moving block sections takes into consideration the location of the rear end of the train ahead with a minimum required overlap.

During the transition to such technology, train integrity control system, which is a part of RBTC, plays the key role as it provides continuous control and data transition on the integrity of the train brake conduit when on the move and during dwell time.

Radio channel serves the purpose of data transmission on traffic situation parameters to train vehicle. The system allows using radio channels of different standards that support digital data transmission. The location of the train vehicle is tracked with the help of onboard measurement equipment that is a part of the onboard system.

NEW RBTC FUNCTIONS

Compared to conventional train control systems at open lines and stations, RBTC implements a number of new functions:

• Possibility of an unconditional stop at the dispatcher’s command;

• Introduction of temporary speed limits at the dispatcher’s command;

• Control of leaving the station area in shunting mode;

• Automatic introduction of temporary speed limits in case of automatic LX failure and stop of a train if protecting signals are switched on;

• Continuous train traffic control and control of its actual location in real-time mode.

SUCCESSFUL IMPLEMENTATION ON THE 1520 mm GAUGE RAILWAYS

The RBTC system changes the traditional approach to efficient train traffic control and allows increasing traffic capacity of lines only due to an increased number of locomotives equipped with the onboard systems. The first ever system was implemented in Kazakhstan and it has been successfully operating in this country for many years, which allows dealing with the constantly rising traffic flow without having to invest in a new infrastructure.

In 2019, after 2 years of detailed and well-coordinated work, 1520 Signal implemented a large-scale innovational project in Mongolia which comprised the design, assembly and commissioning of 1111 kilometers of radio-based train control system on the Khoit — Ulaanbataar — Zamynuud section. For the first time in the world’s practice, radio-based train control system (RBTC) with moving block sections was installed over the existing systems of relay interlocking.

The system is based on the principles of moving block sections, where the succession time remains unchanged, but can be reduced down to 90 seconds, and the factual distance between trains dynamically changes depending on the speed of the train, based on the calculation of braking curve by onboard systems that take the characteristics of a particular train in consideration. The complex system has an in-built diagnostic system and completely eliminates human errors. The application of the system has improved the efficiency of railway transport by significantly increasing the traffic capacity, reducing operational costs, energy consumption and wear of tracks and rolling stocks.

PRODUCTS