Systemet STREAM

Stream is an original concept public transport system, designed and built by Ansaldobreda.
Stream, a medium capacity system, operates on a network installed in the roadway from which it collects traction power and over which it exchanges control signals and messages.

Lane

Stream vehicles run along regular road traffic lanes installed with contact lines.

Power supply

Traction power is delivered by ac/dc current converters which receive ac voltage at 380V and transform it to 500 Vdc. The converters are distributed along the line in special compact cabinets to reduce environmental impact. Power can be tapped from existing low voltage cabins owned by the local Power Company or from special electric substations (750 Vdc). Mixed solutions may also be designed.

Contact line

The contact line is installed in the roadway in a 30 cm deep, 60 cm wide trench. The prefabricated, box structure modules are rigid and waterproof, and contain the flexible power conductor or belt. Each module is between 3 and 6 meters long, divided into insulated metal segments about 48 cm long. The segments are connected to the power supply voltage by the magnetic force exerted by the pick up under the vehicle. This raises the power belt (which normally rests on the bottom of the contact line modules) making contact with the metal plates above. The current absorbed by the traction motor through the positive shoe returns through the second shoe to the negative pole formed by one of the non-energised contact line segments.

Current collector

The current collector comprises a magnet and a series of positive and negative current collector shoes fixed to the magnet unit. An arm and sliding bar mechanism enables the collector to move through three axes with respect to the vehicle.

Automation system

The automation system can be tailored to particular operating and technological specifications. Vehicle presence on the contact line is monitored constantly. This information can be used for ancillary functions including traffic light priority public information at vehicle stops and internal diagnostics.

Vehicle

The vehicle is powered electrically from a contact line or other source and is fully Iow-deck. The proposed standard width is 2.5 m, with vehicle lengths of 12, 18 and 24 m. Vehicle capacity is about 160 - 180 passengers in the maximum configuration. Different seated/standing arrangement may increase that figure.

STREAM TRANSPORTATION SYSTEM IN TRIESTE

The Trieste local transport authority ACT and Ansaldobreda have signed a contract covering the experimentation, development and future implementation of Stream in both Trieste and other markets. The project requires a year to complete (but the system is operational in phases before this deadline) and exploits Ansaldobreda's construction technology skills and ACT's operating expertise in preparing the definitive version of the product.