Mantena is a Norwegian rolling stock maintenance company owned by Norges Statsbaner (Norwegian State Railways). It has workshops at Grorud and Lodalen in Oslo, Marienborg in Trondheim as well as in Skien, Drammen and Stavanger . In addition to NSB, customers include CargoNet, Kollektivtransportproduksjon, Ofotbanen, Green Cargo, Hector Rail and T