Hartzell joined Mack Defense, an integral part of Mack Trucks, as director of engineering in 2015 and became senior director of product development, purchasing and projects in 2017. He first joined Mack Trucks as a staff engineer in 1988. He was chief engineer for electrical and electronic engineering beginning in 1998 before becoming director of product planning in 2003 and director of product development in 2005.
Hartzell has a bachelor’s degree in electrical engineering from Penn State University. He is headquartered in Allentown, Pennsylvania.
Mack Defense, a wholly-owned subsidiary of Mack Trucks, is responsible for the sale of heavy duty trucks to federal- and ministerial-level customers globally.
Mack Defense, LLC, is part of the Volvo Group, one of the world's leading manufacturers of trucks, buses, construction equipment and marine and industrial engines. The Group also provides complete solutions for financing and service. The Volvo Group, with its headquarters in Gothenburg, Sweden, employs about 95,000 people, has production facilities in 18 countries and sells its products in more than 190 markets. In 2016, the Volvo Group's net sales amounted to about $33 billion. The Volvo Group is a publicly-held company. Volvo shares are listed on Nasdaq Stockholm.