InterFlow by Bombardier

InterFlow is a communication-based system with Automatic Train Protection, ATP. Thereare no track-circuits or signals along the track. Train separation is implemented with movingblock.

Fig. 1: Moving and flexible block

The ATP function includes both service and emergency brake intervention.

Fig. 2: Driver with InterFlow Cab signalling

Driver information is given by cab signalling on a graphical colour display.

An InterFlow system has a flat architecture with a minimum of equipment. This results in asystem with very low installation and maintenance costs. The only components that changeswith the system size are the number of balises, object controllers and point machines. As thebalises are passive and the object controllers added in parallel the flatness of the system iskept, regardless of system size.

Fig. 3: Train and wayside equipment

The InterFlow control software, interlocking and RBC, runs in the same computer. Almostindependent of system size, only one computer is needed. The computer can be any PC serverrunning the SUN Solaris (UNIX) operating systems. The interlocking computer is hencereadily available on any market and service normally within a phone call away.

InterFlow is designed to automatically optimise the transport capacity in a system withtimetable controlled traffic mixed with randomly initiated transports, rather than just runtimetable-based traffic.

Manual dispatching and system supervision is performed on workstations connected to theInterlocking computer on a wide or local area network (WAN/LAN). This permits thedistribution of the workstations in the system to the coverage of the computer network. Thedispatch and system supervision is done on Windows workstations and with object orientedWindows applications.

Fig. 4: Windows workstations for CTC

As an add-on feature to InterFlow, there is an Automatic Train and Transport Manager(ATTM). ATTM is an automatic dispatcher that can initiate and handle transports issued bydispatchers, other computer systems, or by train drivers on their cab signalling screen.

InterFlow supports Automatic Train Operation, ATO. By adding an ATO computer, and aninterface to the drive controls of the locomotive, driver-less operation can be obtained. ATOoperation reduces maintenance as the trains can be run according to programmed controlledconditions with smother acceleration and braking.

In an InterFlow system any radio communication system with data transfer capabilities can beused. This makes it easy to find a system certified for the local market, and with localcompetition a reduced price and better service. On longer distances public phone systems canbe used or open networks, such as GPRS.

InterFlow has no practical limitations to system size, complexity or automation level. AnInterFlow system can be expanded or changed during operation and normally the customer iseducated to be able to handle this without assistance from Bombardier.

By thorough education, the intention is that the system administrators should be able tointroduce changes and extensions to the system themselves. All the necessary tools for this isprovided with the system.

Fig. 5: System definition tool in Windows

InterFlow automatically optimises the traffic flow with regards to the total production flow,specific high priority transports and deadlock handling. Train routes are automatically set tominimise the transport time, not the distance. The route for a specific train is constantlyrecalculated during the transport to adapt the traffic dynamically. Trains are stopped at

convenient locations or if possible re-routed to automatically avoid deadlocks or trafficcongestion.

The architecture and the selection of safe components for critical functions guarantee thesafety in an InterFlow system.

The ATP equipment, in the locomotives, and point machine control are the same as used inBombardiers other mainline systems.

Fig. 6: ATP installation

When dispatched the trains are always given a maximum distance to go and then stop withoutany release speed. If the driver or ATO tries to move outside the given safe area, the train isautomatically emergency stopped.

Fig. 7: Cab signalling Display

InterFlow is available now and has been in commercial operation since more than two years.