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Mack Defense submits armored heavy dump truck for U.S. Army testing

Suppliers join truck maker in building beast to withstand destructive live fire

The Mack Defense subsidiary has delivered the first of up to 683 armored dump trucks to the U.S. Army for testing that includes live machine gun fire,.

The first of up to 683 Mack Granite-based heavy-duty armored dump trucks are undergoing testing by the U.S. Army to see how well they hold up under destructive fire. 

Mack Defense won the $296 million contract in May 2018 over Navistar Defense, a unit of Navistar International Corp. Navistar sold 70 percent of its defense business to Cerberus Capital Management in October 2018.

The Mack Defense M917A3 HDT has heavier-duty rear axles, all-wheel drive, increased suspension ride height and other features to meet the Army’s payload and mobility demands. The Army requires the new trucks be able to handle 22.5-ton payloads of sand and gravel, crushed rock, hot paving mixes, earth, clay, rubble and large boulders.

Testing is being conducted at the Army Aberdeen Proving Ground in Maryland.


Machine gun fire

The Army is mum about specifics of the “destructive live fire” portion of the 40-week testing program.

“Testing methodologies, as well as emerging and final results are generally classified, especially when related to ballistics testing,” an Army spokeswoman said.

The Army’s former product manager for heavy tactical vehicles was more forthcoming in an interview with Trucks.com in March.


“We will literally shoot it with machine guns and blow it up and see what happens,” Lt. Col. Jeff Jurand said.  

The Army wants to assure soldiers in the armored compartment can survive a large-scale blast.

“The most important asset to the Army is its soldiers,” Jurand said. “I can buy dump trucks. But I can’t buy, train and replace soldiers.”

The trucks will perform humanitarian missions, repair supply routes and create helipads and landing strips in countries like Afghanistan and Iraq. Soldiers and engineers assigned to the trucks will be protected based on threats they are most likely to encounter. But they won’t carry weapons like other military vehicles.

Supplier choice

Mack Defense carefully chose suppliers for the Army contract including:

TenCate Advance Armor Inc. created the armored cab. Mack and TenCate conducted their own live-fire test on the cab, according to Jurand.

Crysteel Manufacturing is providing specialized dump bodies that include an integrated touchscreen control module. The driver can control the hoist, tailgate, tarp, thermostatic body heater system, material control system, the inclinometer and the on-board weigh scale.


Truck-Lite Co., which has produced military-spec lighting since 1998. For the M917A3 HDT program, it is providing blackout drive lights, front and rear composite lights and auxiliary lighting.

The Mack Defense M917A3 heavy-duty dump truck is undergoing live-fire testing by the U.S. Army. Photo: Mack Defense)

“We needed partners that could engineer and build components tough enough to pair with the Mack Defense M917A3 and meet the U.S. Army’s demanding applications,” said Mack Defense President David Hartzell. Mack Defense is a wholly owned subsidiary of Mack Trucks and part of the Volvo Group.

Aging Army fleet

Some of the Army’s heavy dump trucks are up to 50 years old. Finding replacement parts is tough. The 1,000-truck fleet is made up of decades-old trucks from Daimler Trucks Freightliner division, AM General and the former International Harvester Co.

“We’ve got readiness problems up and down the fleet for heavy dump trucks, so the Army decided to launch a program to try to get that fleet healthy,” Jurand said.

Alan Adler

Alan Adler is an award-winning journalist who worked for The Associated Press and the Detroit Free Press. He also spent two decades in domestic and international media relations and executive communications with General Motors.