INTRO: Signalling and traffic control centres continue to grow, with the operator’s task increasingly assisted by features such as automatic route-setting and integrated train scheduling. But the size and complexity of such installations can create problems when incidents occur, making thorough preparation through training essential if staff are to manage such events safely and efficiently

BYLINE: Dipl-Ing Carsten Trog

Project ManagerVossloh System-Technik GmbH

INCREASING commercial pressures are making it ever more difficult for railway operators to train signalling staff on new installations in the traditional manner, as the window between the completion of a new facility and its entry into service gets smaller and smaller. And even when opportunities for training can be found, such as when fewer trains are running, it can be difficult to train effectively for emergencies such as a major power failure without risking disruption to the network.

The aviation and military sectors face similar problems, where real crisis situations cannot be deliberately created just for the sake of staff preparedness. As a result, the use of simulators has become well established for many aspects of training, and it has often been observed that with realistic installations trainees ’forget’ after a short period of time that they are sitting at a simulator and behave just as if they were dealing with a real system.

Vossloh System-Technik has developed a system which simulates all the functions of an electronic signalling control centre necessary for training an operator. The guiding principal has been to replicate as closely as possible the real operating environment, including the signalling rules of the railway in question and the detailed layout of each station.

System hardware consists of standard industrial PCs, connected using TCP/IP in a Local Area Network. Hardware costs are kept low through the use of standard products and protocols; the system can also be moved to wherever operators need to be trained. A typical configuration is a trainer’s PC with one monitor and two trainee workstations with eight monitors each, the standard configuration of workstations in DB Netz operations control centres on the German Railway network.

The software runs on Windows NT and shows the same events on all three workstations, with the trainees operating two different workstations controlling the same section of route. The trainer controls the simulation, generates trains and activates disturbances. But this configuration is flexible and can be arranged as a single workstation, or even to provide four different simulations at the same time controlled by one trainer.

To add to the realism, trains can be modelled with many varying characteristics, including length, weight, number of cars and type of locomotive. The acceleration and braking of different types of rolling stock can also be replicated, presenting the trainee with a realistic representation of the operating railway.

Operators and timetables

Over 300 different potentially disruptive incidents can be activated by the trainer. These range from the failure of signal lamp filaments and track circuits to more complex situations such as point blades failing to move to the correct position or a point motor losing power. System failures can be simulated, requiring special operating procedures to be put into effect in place of block working, and varying degrees of disruption to the power supply can be introduced.

Faults within the control centre itself can also be simulated, from monitors failing to display the full range of colours to computer system failures and deployment of back-up systems. Staff can practice operating under different degrees of power failure, according to the characteristics of the real signalling system for which they are being trained.

Disruption events are triggered by the trainer using a dialogue box within the training program. The trainee must then analyse the situation from the on-screen display and take the appropriate course of action according to the signalling rules and the options available.

The trainer can generate single trains with desired parameters in any location. In addition, the trainer can play the role of a driver instructed to pass a red signal or who is seeking authority to leave a siding in the course of a shunting movement. The system also enables all types of movements to be simulated, including the joining and splitting of trains.

For training staff on a new station layout or timetable, the time schedule function offers the possibility of importing schedule data electronically. The data can be edited before being used to generate trains in the simulation. This relieves the trainer of routine work such as generating many trains, and provides the opportunity to test a new timetable.

Another scenario for training may be a certain traffic situation where disturbances occur at a certain time. For such a situation repeating itself on a regular basis, a macro file can be prepared by the trainer which will generate defined train movements and disturbances. The trainer can still intervene as desired, and statistical functions can be used to analyse how students performed.

There are other software packages on the market for simulating timetabled railway operations, but most are not designed with signalling staff in mind. The VST system was used to train DB Netz signalling staff in advance of Expo 2000 in Hannover, for which many new services were introduced (RG 7.00 p402). The simulation represented three different locations using a total of four workstations, connected on a LAN to allow trains to pass from one area to another. Staff trained on the signalling centre with which they were already familiar, but operating the new timetable with a total of 1000 train movements a day.

Each operator had two to three days of training, and plans were developed for dealing with incidents likely to cause disruption, such as a train breaking down at a critical location. This training exercise also revealed some conflicting movements, and adjustments were accordingly made to the timetable before it came into force. In the same way, operations over new lines or layouts can be tested while these projects are still at the planning or construction phase.

Routine simulation

DB Netz is currently the largest single user of VST training simulations, which are now used before almost every major electronic interlocking is put into service. An intensive training programme forms part of the commissioning process, ensuring a smooth transition to the new system, as has been the case for the installations in Hannover, Bremen and Dresden.

A total of 11 simulation systems are now used by DB Netz to train signallers, with the principal systems located at the seven Betriebszentralen where traffic control functions are partly integrated with signalling (RG 6.00 p365).

Simulation-based training is most commonly used prior to the commissioning of new electronic interlockings, starting some six months before the real system is put in operation. This leaves sufficient time to cover special local conditions, and to train for a wide range of potentially disruptive incidents. Held during normal working hours, training sessions can be conducted at any of the seven operations centres.

During training prior to commissioning, operating staff can also discover any shortcomings that may exist in the new installation, allowing them to be rectified before it enters service.

Austrian Federal Railways has recently ordered simulation systems for future interlocking installations, as well as a further 75 existing installations on its network. Screen displays for new installations can be generated for testing by the operators who will use them.

Once the cost of altering new track layouts and moving lineside signalling equipment is taken into consideration, the advantages of using simulation in the design and planning process become clear. Modelling a station layout represents between 0·5% and 1% of the total cost of a new interlocking, and a training system - being the result of the planning simulation - is provided at the same time for no additional cost.

Although the benefits of simulation are well known in other industries, it is only quite recently that it has entered widespread use in the field of railway signalling. Its usefulness during the design phase and for staff training has already been demonstrated, and it is likely that simulation will be used on an ever-increasing basis throughout the life cycle of a major signalling installation.

CAPTION: Top: To ensure maximum realism, the workstation used for training is made as similar as possible to its counterpart at a real operations control centre

CAPTION: During simulation-based training, the operator uses a display identical to that in a real control centre, such as that for the Bischofswerda area on the DB network. Train data and potential turnout faults are seen on this display