ran a higher frequency of departures between Rognan and Bodø. This service has become a success. This was not the case when the same trains were put in as replacements on the intercity trains. Although allowing for almost an hour faster travel, they had fewer amenities and little space. Passengers protested, and after trials from 2003, Di 4s with carriages were reintroduced during the summers from 2003 and all year from 2007. From 2006 the sleeper services were cut from Mosjøen and Mo i Rana. The Nordland Line had not received NSB's first generation of train radio, Scanet, so was among the first lines to receive GSM-R from 1 December 2004. NSB's cargo division, CargoNet, introduced EMD Class 66 locomotives from 2003. These were replaced with Vossloh Euro in 2010. Centralized traffic control from Grong to Majavatn was implemented in 2007, and to Eiterstraum from 2011. The same year the Gevingåsen Tunnel opened south of Trondheim Airport. The newer B5 carriages were introduced on intercity trains in 2012. Architecture Buildings along the Meråker Line, and hence the stations from Trondheim to Hell, were designed by Peter Andreas Blix. The stations bear resemblance to other Norwegian stations from the era, Few of these buildings remain intact, as they have mostly been expanded later. Blix' buildings were freer modeled, often taking an asymmetrical shape to suit its function. Stylistically the buildings have Medieval and New Gothic inspiration. The exception is Trondheim Central Station, a plastered brick building designed by Balthazar Lange in New Renaissance style. Stations along the Hell–Sunnan Line were designed by Paul Due. These had a more grandiose expression, which stylewise represent a transition between Swiss chalet style and Dragon Style on the one hand and Art Nouveau on the other. Many of the smaller stations received a ground floor in stone and an upper story in wood. Steinkjer and Levanger were both built in plastered brick. The section from Sunnan to Grong was designed by Eivind Gleditsch and in a transitional style between Historicism and Neo Classism. Increased standardization had been taken into use and the so-called Veggli Class or variations of it were used on most smaller station through Namdal. As the line continued northwards, reduced spending on architectural elegance caused simpler and simpler designs in wood. Once the line reached Salten it was evident that steam traction would soon be history and the functional layout of the