Mack Defense secures five-year U.S. Army contract

Mack Defense announced it has been awarded a new five-year contract to continue production of the U.S. Army’s M917A3 Heavy Dump Truck (HDT) for up to 450 trucks with a total contract value up to $221.8 million. The new agreement follows the fulfillment of an initial contract awarded in 2018 and comes after the company recently celebrated the production of its 500th M917A3 HDT in March 2025.

Based on the Mack Granite, the M917A3 HDT has been modified to meet mission-critical functionality in support of U.S. military operations. (Photo: Mack Defense)

The initial contract award allowed for up to 683 trucks at a value up to $296 million. The U.S. military has ordered 549 HDTs from Mack Defense, with additional orders coming from both the U.S. Army and U.S. National Guard.

This new contract “represents continued confidence in our ability to deliver mission-critical vehicles to the U.S. Army,” said David Hartzell, president of Mack Defense. He added that it “is a testament to the commitment of our team, which includes our supplier partners, as well as to the robust capabilities of this heavy tactical vehicle platform.”

Based on the commercially available Mack Granite model, the M917A3 HDT has been modified to meet mission-critical functionality in support of U.S. Army, Army Reserve and Army National Guard operations. The vehicles are spec’d with heavier-duty rear axles, all-wheel drive, increased suspension ride height and other ruggedized features to meet the unique requirements of the U.S. military. They also feature advanced technology including ABS, modern control interfaces and active safety systems.

The vehicles are used in the U.S. military’s construction and infrastructure maintenance operations within the United States and globally. They support construction and upkeep of airfields, roadways, landing strips, supply facilities and motor pools, and disaster relief for areas affected by severe weather.

The M917A3 HDTs are manufactured on Mack Defense’s dedicated production line at the Mack Experience Center (MEC) in Allentown, Penn., USA. The specialized production facility has been in operation since 2021 following a $6.5 million investment to create the dedicated HDT production line.

Mack Defense to supply 103 HDTs to U.S. Army Order part of the U.S. Army M917A3 Heavy Dump Truck Program