110.021 led IR2221, the 12:04 from Interlaken Ost to Luzern, formed mainly of coaches in Golden Pass livery, along the Aare Valley east of Brienzwiler on 6 October 2012.
The Golden Pass is a joint service operated by the MOB from Montreux to Zweisimmen, the BLS on to Interlaken then the ZB to Luzern. Although the end sections are both metre gauge, Zweisimmen - Interlaken is standard gauge and involves a change of trains at both ends.