First metro to convert to full automation: Nuremberg Transport is on course to become the first metro in the world to convert an existing manually-operated line to full automation. Automatic operation will start in spring 2006

International Railway Journal, Sept, 2004 by David Briginshaw

RUBIN is the acronym for the project to implement a fully-automated U-Bahn in Nuremberg. Dipl-Ing Konrad Schmidt, Nuremberg Transport's (VAG) project manager, is very enthusiastic about the benefits Rubin will bring, as he explained to IRJ.

"Automatic operation is cheaper than manual because there will be no need for drivers, and drivers account for the largest portion of our operating costs," Schmidt said. "We will use less energy because the system will calculate an energy-optimised speed profile. We will need fewer vehicles than with conventional operation because we will be able to turn the trains round faster. We will be able to operate shorter trains more frequently, which will have benefits for passengers and make the service more attractive. The experience of other operators of automatic metros is that automatic operation is more reliable than manual operation."

There were several reasons why VAG decided to convert one of its two lines to automatic driverless operation. Two branches were to be added to the existing Line U2 to create a new Line U3. Trains operating on both lines will share a common section of track through the city centre between Rathenanplatz and Rothenburger Strasse. "This meant we would need a new signalling system for the combined U2/U3 lines," Schmidt said. The U-Bahn also lacked any type of semi-automation. The first generation of trains on the U-Bahn was about 30 years old--the first section opened in 1972--and therefore needed to be replaced, plus additional trains would be needed for Line U3. This presented VAG with a window of opportunity to take the plunge into full automation; otherwise it would probably have to wait another 10 years for another opportunity to convert.

Feasibility and profitability studies were conducted to ensure that the Rubin project would be viable both technically and financially. VAG estimates that the cost of converting Line U2 and installing and maintaining the additional equipment needed for full automation will be offset, at a ratio of more than 2:1, by the reduced operating costs and additional revenue from the anticipated growth in passenger traffic (see graph). VAG has worked out three payback scenarios based on a 30-year life. Under the worst case scenario it would take 18-19 years to achieve pay-back, the realistic scenario is 9-11 years, and the optimistic scenario is 6-7 years. "We are currently following the realistic scenario. Schmidt observed.

This is despite the fact that the existing drivers on Line U2 will not be made redundant. Indeed, VAG has an agreement with the trades unions that nobody will be laid off because of Rubin. Instead, the drivers will be redeployed as service staff at stations. "We will have a service person at every third station," Schmidt explained. They will assist passengers, check technical equipment such as lifts and escalators, and be the first person on-hand to deal with any faults on the trains.

The cost of constructing the first phase of Line U3 is about 300 million [euro]. The cost of installing all of the equipment needed for automatic operation on Lines U2 and U3 as well as on the trains is estimated at a further 100 million [euro]. The 30 two-car trains will cost an additional 140 million [euro].

Siemens was awarded a contract in November 2001 to install all the equipment needed for the Rubin project and supply the new trains. The first of these has now arrived in Nuremberg, and testing should begin shortly. The first trials will be conducted on a short test track. Test running on the Rathenauplatz-Rothenburger Strasse section will commence in spring 2005. VAG will begin final testing of the whole system in autumn 2005. When Line U3 opens in February 2006, there be mixed operation of automatic trains on Line U3 and manually-operated trains on Line U2. Full automatic operation on both lines will begin in November 2007.

The Rubin project involves a mixture of tried and tested technology with a number of innovations such as the continuous bi-directional transmission of data. Existing technology includes Vicos OS 501 and OS 111 automatic train supervision, LZB series 500 automatic train control (ATC), and Sicas electronic interlockings. VAG will retain relay interlockings on Line U2 with an interface to the ATC. The trains are based on those designed by Siemens for the Vienna U-Bahn but adapted for driverless operation.

A key concern with driverless operation is the safety and security of passengers, and this is where most of the innovations are being made. Fire-retardant cables will be fitted throughout, 750V cables will be protected in armoured steel tubing, and train disk brakes will be made of aluminium. On-board smoke and temperature detectors, similar to those installed in aircraft, will send an alarm from the train to the control centre and hold the train at the next station.

Two cameras will be fitted in each coach, with live transmission of pictures to the control centre. "We will effectively transfer the driver's eye to the control centre," Schmidt explained. "There will also he emergency intercoms in the trains linked to the control centre.