Rhatische Bahn No.X9213 Winterthur 0-6-6-0 steam powered snow blower of 1910 clears the line above Pontresina using only steam power on 29/1/2011 during a demonstration run over the Bernina pass.
Update 2014… this clip was used in a British Channel 4 documentary presented by Tony Robinson, «The Worlds Most Extreme — Railways»