Mack Defense delivers first HDTs to army

Mack has delivered the first production M917A3 Heavy Dump Trucks (HDT) to roll off Mack Defense’s new production line at the Mack Experience Center (MEC) in Allentown, Pa.

Mack Defense has delivered to the U.S. Army and the U.S. Army Reserve the first production M917A3 Heavy Dump Trucks (HDT) to roll off Mack Defense’s new production line at the Mack Experience Center (MEC) in Allentown, Pa.

“It’s an honor to write the next chapter in Mack’s rich history of producing vehicles for the U.S. armed forces on this dedicated line and deliver the first, new Heavy Tactical Wheeled Vehicle the U.S. Army has added to their portfolio in 12 years,” said David Hartzell, president of Mack Defense. “We look forward to fulfilling our current contract and the needs of the U.S. Army, delivering vehicles that have earned the acceptance of the armed forces through successful rounds of rigorous testing.”

Based on the commercially available Mack Granite vocational truck, the M917A3 trucks are part of the contract for HDTs that was previously announced between the U.S. Army and Mack Defense. The Army uses dump trucks in its engineer units and said they are key in construction and maintenance missions for important infrastructure assets, like roadways, airfields, landing strips, supply facilities and motor pools.

“Many of the Army’s missions are within extremely austere environments, so if we need to build things to support combat or training operations, dump trucks are absolutely essential to the force,” said Wolfgang Petermann, the U.S. Army’s project manager for Transportation Systems, Program Executive Office for Combat Support & Combat Service Support (Detroit Arsenal, Michigan).

The Mack Defense production line at the Mack Experience Center.

The Army’s current dump truck fleet includes some variants that are nearly 50 years old, Petermann said. “Now is the perfect time to provide the Engineer Regiment with modified commercial off-the-shelf capabilities leveraging the strength of the commercial auto and heavy-duty trucking industry,” he said.

In May 2018, the U.S. Army awarded Mack Defense the contract that could be worth up to $296.4 million over seven years to produce up to 683 non-armored and armored M917A3 HDTs. The U.S. Army signed the agreement Nov. 30, 2020 to purchase 99 Mack Granite-based HDT’s after completing two years of successful Production Vehicle Testing of 12 vehicles at the U.S. Army’s Aberdeen Test Center in Aberdeen, Md, in accordance with the contract program timeline. Then on March 29, 2021 an additional order of 56 HDTs were placed as part of the 2021 Presidential budget.

Investment in production

Production of the HDTs at the MEC began in Q1 2021, following an investment of $6.5 million to create a dedicated HDT production line at the facility. The new production line helps fulfill the HDT contract with the U.S. Army and allows the production of other vehicle variants.

The production line in the MEC is in Mack’s former Customer Adaptation Center, where vehicle modifications occurred. The Customer Adaptation Center has since moved to Mack’s Lehigh Valley Operations (LVO) in Macungie, Pa., where all Mack Trucks Class 8 vehicles for North America and export are assembled. Previously, non-armored HDT vehicles started production at LVO and were then transported to the MEC, where final assembly, including adding the dump body, occurred.

The 94,500 lb. GVWR M917A3 incorporates a 13 L Mack MP8 engine rated 440 hp with 1660 lb. ft. of torque. The engine drives an Allison 4500 Gen5 six-speed automatic transmission, which delivers power through Meritor Permalube RPL driveshafts to the rear axles and a Fabco TC142 transfer case for the front axle drive.

The front axle is a Meritor MX-810 suspension axle, while a Meritor P600/ProTec Series 50 rated 76,800 lb. is in the rear. Meritor also supplies the brakes, with EX+ air disc brakes in front and Meritor-Cam 16.5 x 7 in. Q+ brakes in the rear.

An armored cab was also engineered, utilizing the comfort features and amenities of a commercial truck, while adding force protection to help keep occupants safe in hostile environments.