"VITA DURA" upstream on the river Rhine (km 387) at Philipsburg (nuclear power plant) near Karlsruhe (Germany), 31.03.2013

Can anyone tell me, what kind of load this "rolls" are? The have a kind of an air flue pipe (More details in full resolution). I have never seen this before?
Vita Dura should be a dry cargo vessel. Thanks in advance - Marc

Further info:

ENI number: 06003286
MMSI: 205303490
Tonage: 3168 ton
Length: 110m
Width: 11.40 m
Built: 1998
Flag: Belgium