A captain in the Naval Engineering Corps, engineer and businessman. Together with Smitt, he put up the capital for the formation of Nitroglycerin Aktiebolaget. He and Captain J. A. Berg were owners of Wennerström & Berg, engaged in stonecutting and similar operations “for which prisoners assigned to hard labor may be used, in accordance with the contract with the National Prison Board,” to quote the corporate registration papers.

Wennerström probably met Nobel during one of the numerous blasting tests of nitroglycerine in Stockholm in the first months of 1864. Wennerström was a board member of Nitroglycerin Aktiebolaget at various stages, and was responsible for clinching Nobel’s first international deal–the formation of Nitroglycerin Compagniet in Norway.