STA, the operator of the Venosta Valley line from Merano to Malles in the Italian province of Bolzano or South Tyrol, has placed into service the first of 21 Coradia Stream EMUs supplied by Alstom following the completion of work to electrify the line at 25kV 50Hz ac.

Manufactured at Alstom’s Savigliano plant in Italy, the 127.9m-long EMUs each have 381 seats, with a continuous power output of 3MW at the wheel and a maximum speed of 160km/h. The multi-system EMUs are equipped with ERTMS, as STA intends to deploy the new fleet on cross-border services to Austria, running from Malles to Lienz and from Bolzano to Innsbruck.

Electrification of the 60km Merano - Malles line was undertaken by GCF and Ineo SCLE Ferroviarie, deploying construction methods specifically developed for the characteristics of the line and the terrain it traverses. These include three types of foundations for the line’s 1700 catenary masts: steel tubes driven into the gravel and alluvial soils of the valley floor; concrete bases where pile driving was not possible; and foundations directly anchored to the rock where this guaranteed high static performance.

Specific metal anchoring structures were used on bridges, while specialised designs were developed for locations near tunnel portals and other concrete structures. Combining high mechanical strength with low weight, the galvanised steel catenary masts were designed to blend into the landscape.

A flexible, compensated catenary system was installed on open-air sections of the line, supported by aluminium alloy brackets. A rigid catenary system was installed in the four tunnels on the line, totalling 2km in length.

Traction current is provided by the main substation located in Coldrano-Vezzano, fed by the 132kV high-voltage grid and equipped with two 7.2MVA single-phase transformers to produce 25kV. The entire line can be powered with just one transformer, while two additional substations at Lagundo and Malles, equipped with 2MVA transformers, ensure continuity of service during emergencies.

Near Malles where the line joins the national network electrified at 3kV dc, a separation section has been installed with 26m of overlapping catenary. According to GCF, this enables the pantograph to move from one electrification system to another without mechanical discontinuity, while ensuring the complete electrical independence of the two systems.

Predictive maintenance

The Merano - Malles line has also been equipped with a contact wire monitoring system. This checks the movement of compensating counterweights in real time and verifies that the mechanical tension of the catenary remains within expected values, immediately reporting any anomalies. GCF says that this will enable a transition from scheduled to predictive catenary maintenance.

In addition, video cameras have been installed along the line to capture images of the pantograph of each passing train, verifying its integrity and promptly identifying any deformation or other anomalies that could compromise the overhead contact line. In the event of a critical issue, the system immediately notifies maintenance personnel.

“The project's digitalisation and innovation features look to the future by shifting infrastructure maintenance towards a data-driven model, in which the infrastructure itself is capable of identifying and reporting anomalies before they have any impact on railway operations,” says GCF CEO, Dr Giuseppe Brecciaroli.

For detailed data on European fleet orders and infrastructure projects, subscribe to IRJ Pro.