the core of the saarbahn—the new line between brebach station and ludwigstraße—was put into operation on 24 october 1997, after just under two and a half years of construction. since its opening, there has been a system separation point between römerkastell and brebach station. this is a 90-metre-long non-energised section of the overhead line, which is traversed using momentum, while the vehicle's electric system automatically switches to the other system. saarbahn railcars coming from central saarbrücken change from 750 volts dc to 15,000 volts ac and run via kleinblittersdorf to sarreguemines, lorraine. the french section from the border station at hanweiler has been equipped with the german electric system since 1983. the first light rail vehicle that reached saarguemines was two-system railcar 810 of the albtal-verkehrs-gesellschaft (avg), which ran there on 11 september 1993 during a presentation ride.