another 10 years passed before the next trolleybus line was opened. this occurred on 24 september 2012, with the partial conversion to trolleybuses of bus line 14, piazza giovanni xxiii – due madonne depot (bus garage) via the city centre. the western half of line 14 had been line 43 of the previous system (the terminus having been called barca during that period, but following exactly the same routing to piazza giovanni xxiii), so this was a reactivation of former line 43, now as part of line 14. the eastern half of line 14 had never previously been a trolleybus line. initially, service on line 14 remains mostly operated with motorbuses, with trolleybus serving only about one-quarter of its trips. this is due partly to there being too few trolleybuses available in the fleet and partly to the fact that line 14 has three branches at its eastern end, two of which are not equipped with trolleybus wiring. the trolleybuses in the current fleet have diesel engines enabling them to operate away from the trolley wires, but only to a limited extent. the 11 newest trolleybuses, delivered in 2010 by solaris bus & coach, have more powerful diesel engines, and initially they are the only trolleybuses being used on line 14, along with many diesel buses for the time being.