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U3 success helps automatisation for the second time around

Posted: 30 March 2009 | Dr. Rainer Müller, Managing Director, VAG | No comments yet

Immediately after the commissioning of the new fully-automatic U3 metro line, VAG Verkehrs-Aktiengesellschaft Nürnberg and Siemens AG, the general contractor, started to automate the existing Nürnberg U2 metro line (Röthenbach – Nuremberg Airport) in the summer of 2008.

As with the automatisation of the new U3 metro line, which started passenger operations on 15 June 2008 according to schedule, both corporations are breaking new ground. The U3 is Germany’s first fully-automated metro line, which also runs in mixed operation with the conventional U2 line on a shared track. The U2 line is the first conventional metro line worldwide to be rebuilt for automatic passenger operation – without interruption to regular operations. The conversion of the U2 line had been planned from the onset and will be carried out successively and train-by-train at the end of 2009.

Immediately after the commissioning of the new fully-automatic U3 metro line, VAG Verkehrs-Aktiengesellschaft Nürnberg and Siemens AG, the general contractor, started to automate the existing Nürnberg U2 metro line (Röthenbach - Nuremberg Airport) in the summer of 2008.As with the automatisation of the new U3 metro line, which started passenger operations on 15 June 2008 according to schedule, both corporations are breaking new ground. The U3 is Germany's first fully-automated metro line, which also runs in mixed operation with the conventional U2 line on a shared track. The U2 line is the first conventional metro line worldwide to be rebuilt for automatic passenger operation - without interruption to regular operations. The conversion of the U2 line had been planned from the onset and will be carried out successively and train-by-train at the end of 2009.

Immediately after the commissioning of the new fully-automatic U3 metro line, VAG Verkehrs-Aktiengesellschaft Nürnberg and Siemens AG, the general contractor, started to automate the existing Nürnberg U2 metro line (Röthenbach – Nuremberg Airport) in the summer of 2008.

As with the automatisation of the new U3 metro line, which started passenger operations on 15 June 2008 according to schedule, both corporations are breaking new ground. The U3 is Germany’s first fully-automated metro line, which also runs in mixed operation with the conventional U2 line on a shared track. The U2 line is the first conventional metro line worldwide to be rebuilt for automatic passenger operation – without interruption to regular operations. The conversion of the U2 line had been planned from the onset and will be carried out successively and train-by-train at the end of 2009.

At the beginning of August 2008, the new metro trains (named DT3) began running up to five nights a week between 1am and 4am in trial operations between the Röthenbach and Nuremberg Airport metro stations. As with the automatisation of the U3 metro line, the tests on the U2 are being controlled and directed by Siemens AG, which built the vehicles, equipped the line and developed the required software.

The trains are now running in automatic operation on the entire U2 line. During these trial runs, it is being checked whether the trains receive the necessary and correct information at each location of the network and carry out the planned actions. There are also functional tests with varying speeds and in different situations. Since the U2 is planned to run mostly with short trains after full conversion to automatic operation, coupling and decoupling as well as turning around and stopping the trains make up the largest part of the trials.

As with the automatisation of the U3, the main focus in these processes is on functionality and ensuring safety in every situation. As with previous years, VAG operators are also on board to intervene if necessary. The trial operation is monitored and controlled by the VAG Operations Control Centre whose reinforced team again becomes active at night. For the colleagues at the Operations Control Centre and the test drivers, the new trial operation means broadening their system knowledge as well as problem analysis and troubleshooting.

The U3 – success so far

While the focus during the night is on the U2 line, during the day attention is paid to the U3. On 4 May 2008, passengers were able to ride its trains on the U3 for the first time. It was officially inaugurated on 14 June 2008 and VAG took up regular passenger operations on the following day. Since then, the trains have been running reliably between the new Gustav-Adolf-Straße and Maxfeld metro stations. The U3 tracks have a total length of 6.1 kilometers. In addition to three new stations, the U3 also stops at six U2 stations.

The U3 has so far been a success and all parties involved are very satisfied with its stable operation. From 15 June 2008 to 31 December 2008, the trains ran 67,750 times and made 575,800 stops at stations, where doors were opened and closed approximately 5,182,800 times!

Availability

Where passengers are concerned, the U3 runs to an availability of 99%. This means that passengers very seldom experience train delays or cancellations of the automatic trains. Reliability is higher than with conventional trains but in the event that a train is delayed, which is partly due to the conventional U2, then waiting times are usually kept to within five to ten minutes. This shows that two different types of operations are much harder to handle than a system with one single type of operation.

The first few months could not have been better and even though there has been an extremely high availability for customers, there is hardly any room for improvement. Adjustment of individual components and the optimisation of the control functions can help to improve optimisation – however, 100% availability will never truly be achieved. Even in new vehicles and relay boxes, parts can break down or require readjusting.

Operations

From an operational perspective, a few processes have been enhanced. Since commissioning, processes have shown to stabilise, which is, among other things, the result of changes to the controls, which facilitates work for the colleagues at the Operations Control Centre and others and no longer requires intervention. Now and then, the routes were not automatically set up by the steering technology, which required manual setup by the controllers at the Operations Control Centre. However, the cause has been detected and controls have been adjusted accordingly. Now, the routes are reliably set up automatically every time.

Vehicle doors

The vehicle doors function at incredibly high operational demands and are generally prone to interference. Mechanical readjustments were needed which helped to sort out teething problems and the vehicle doors now function properly. If problems with doors closing do arise, the KUSS staff – who are currently on board every vehicle – can usually intervene promptly for passengers to not even notice the disturbances.

Door interferences are caused by the setting of the doors related to the car body, which, in individual cases, causes the software to ignore that a door has already been closed. However, safety with regard to the doors is of paramount importance and given attention immediately. This has been proven in daily operations.

Vehicle operations

Since the new metro line was commissioned, the parameters of the vehicle software have also been optimised. In contrast to the first few weeks of operation, the vehicles now accelerate up to the permissible maximum speed in a consistent manner. Previously, attentive passengers were able to perceive interruptions in the acceleration processes. With consistent speeds, the DT3 vehicles are now also passing the gaps in the conductor rails. Here, the regulation responsibility is now exclusively with the ATO (Automatic Train Operation), the virtual driver. Before, even in the automatic operation, the vehicles used a function that shortly interrupted overall power supply to the trains as the trains passed short gaps in the conductor rails. This is to avoid that, with long gaps in the conductor rails, electric arcs are created that lead to increased wear and tear of the vehicle’s collector. However, this is not the case with short gaps in the conductor rails.

Over the past few months, VAG and Siemens have also adjusted the U3’s driving and stopping durations in individual cases. Depending on the time of day and the stations, these time spans have been defined differently. Detailed evaluations also serve to detect where driving speed can be made more consistent, travel times can be shortened, or reserves can be used. In part, changes can already be implemented successively. However, on the whole, the results serve to develop a schedule and operation as optimised as possible for the full conversion of the U2 to automatic operation.

Thanks to extensive communication with passengers and their feedback, the city’s entire population was well prepared for the automated metro line. From the onset, passengers handled the new system perfectly.

U2 conversion to start at the end of 2009

At the end of 2009, conversion of the U2 to automated passenger operation will be executed step-by-step. In long processes, one conventional vehicle after the other will then be replaced by an automated one. Prior to the conversion, all the new functions and line sectors will be thoroughly tested for defects and stability of all the processes. The experts will again be required to investigate all safety-relevant aspects and to give the Technical Supervisory Authorities their statements as a basis for a decision on the final release of the metro line for passenger operation. In part, the experts will work simultaneously to the trial operation, but will in any event be the last ones to examine the entire system. As with the U3 automatisation, the Technical Supervisory Authorities will release the U2 for automatic passenger operation following a six-week trial operation conducted by VAG.

Passengers in Nürnberg will then enjoy one of the world’s most modern and efficient metro systems encompassing two automated lines. As was shown in the city districts that have been made accessible in summer 2008, this will hopefully lead to further far-reaching positive reactions.

The success is based on the work of the highly motivated manufacturers, VAG project teams, subcontractors and the many operational divisions at VAG that have been intensively supporting the project teams during the entire duration.

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