20_ERTMS ETCS Level 3

ERTMS / ETCS Level 3 Good morning everyone. Today we are going to study ERTMS / ETCS Level 3, which is considered the most advanced and sophisticated level of the European Train Control System. Level 3 represents the future of railway signaling, especially for high-speed and high-capacity railway networks. In this lecture we will understand: • How Level 3 works • How trains are located and controlled • The concept of the moving block system • And the advantages and challenges of this technology. ________________________________________ Introduction to Level 3 ERTMS Level 3 is a continuous train protection system. One of the most important features of Level 3 is that track circuits are no longer required to detect the position of the train. Instead, the system relies mainly on train-based position reporting. This means that the train itself determines its own position and sends that information to the control center. Because of this feature, Level 3 significantly reduces trackside equipment and makes the railway system more efficient. ________________________________________ Train Position Detection In Level 3, the train determines its position using onboard equipment. This equipment is called Eurocab, which is the onboard ETCS computer. The Eurocab calculates the train's position using odometry systems, such as: • Wheel sensors • Speed sensors • Distance measuring equipment After calculating the position, the train sends this information to the Radio Block Center, commonly known as the RBC. The RBC continuously monitors the position of all trains on the network. ________________________________________ Use of Position Beacons Even though trains determine their own position, position beacons, also called balises, are still used. Their purpose is not to detect trains, but to correct small errors in the odometry system. As trains travel long distances, odometry measurements can slightly drift. Balises help reset and correct the position information, ensuring that the train location remains accurate. This improves the reliability and safety of the system. ________________________________________ Moving Block System One of the most revolutionary features of Level 3 is the moving block system. In traditional railway signaling systems, tracks are divided into fixed blocks. Only one train is allowed inside a block at a time. But in Level 3, blocks are not fixed. Instead, the safe distance between trains moves dynamically with the train. The RBC continuously calculates the safe braking distance between trains and allows movement accordingly. This allows trains to operate closer together while maintaining safety. ________________________________________ Role of the Radio Block Center The Radio Block Center, or RBC, plays a very important role in Level 3 operations. The RBC receives position reports from all trains. Using this information, it performs several functions: • Monitoring train positions • Calculating safe movement authorities • Managing train traffic • Ensuring safe distances between trains Based on this information, the RBC authorizes trains to move up to the safe distance behind the preceding train. ________________________________________ Elimination of Trackside Signals Another important feature of Level 3 is that trackside signals are no longer required. All signaling information is displayed directly inside the train cab. This is especially important for high-speed trains. At very high speeds, drivers may find it difficult to see trackside signals due to what is known as the tunnel effect, where peripheral vision becomes reduced. Therefore, displaying signals directly inside the cab improves safety and clarity. ________________________________________ Cab Signaling In Level 3 systems, all signaling information is shown on the Driver Machine Interface, commonly known as the DMI. The DMI displays important information such as: • Current speed • Maximum permitted speed • Movement authority • Distance to braking points • Warning messages This allows the driver to operate the train safely using real-time digital information.