Prior to the integration with the TMB network , L6 covered as an underground commuter train line the distance from downtown Barcelona to SarriÃ , pretty much the same as nowadays . It has its origins in 1876 , with the Barcelona-Sarri Ã train . L6 originated in 1876 as the Barcelona-Sarri Ã commuter train and has changed little since its integration into the network of TMB .