U.S. Army Orders 115 Mack M917A3 Trucks for National Guard Route and Airfield Repair.

Mack Defense announced on July 14, 2026, that the U.S. Army had ordered 115 additional M917A3 Heavy Dump Trucks for the Army National Guard, expanding its ability to rebuild routes, airfields, and logistics hubs under demanding conditions. Each protected 8×8 truck can carry up to 27 tons of aggregate, earth, rubble, or paving material, giving Guard units more capacity to restore mobility and sustain operations after combat damage or disasters.

The order follows a 2025 contract covering up to 450 trucks and adds to an earlier purchase of 91 vehicles funded in fiscal year 2026. Mack did not disclose delivery timing, unit cost, or armored-cab allocation, while its stated combined total of 208 trucks differs from the 206 vehicles represented by the two announced orders.

Related topic: Canada Orders 190 More ACSV Armored Vehicles to Strengthen NATO Ops and Replace Aging Support Fleets.

The U.S. Army has ordered 115 additional Mack Defense M917A3 8x8 Heavy Dump Trucks for the Army National Guard, adding protected 27-ton construction vehicles for route repair, airfield development, earthmoving, and logistics support in contested and austere environments (Picture source: Mack Defense).

The M917A3 is based on the Mack Granite commercial truck design but incorporates a military 8×8 driveline, reinforced chassis, increased ride height, heavier axles, blackout lighting, and provisions for an armored cab and military communications. Gross vehicle weight rating is 94,500 pounds, with a 243-inch wheelbase and a payload rating of up to 27 tons, or 54,000 pounds. The Crysteel dump body has an 18-cubic-yard capacity, increased to 22 cubic yards with sideboards, meaning that payload weight rather than volume will often become the limiting factor when hauling dense crushed rock or wet soil. The material-control system permits operators to regulate discharge through the tailgate instead of dumping the entire load at one location, which is relevant when laying aggregate over a damaged road or preparing a graded surface. A heated body allows asphalt to remain workable during transport, while external controls reduce the need for soldiers to climb onto the truck during unloading.

Power is supplied by a nominal 13-liter Mack MP8 inline six-cylinder turbo-diesel rated at 440 horsepower and 1,650 pound-feet of torque. It drives an Allison 4500SP automatic transmission and a Meritor TC142 two-speed transfer case with high, low, and neutral ranges. The low range is more important than maximum road speed for this mission because a loaded dump truck must start on loose surfaces, maintain controlled movement on gradients, and avoid excessive wheelspin near excavation sites. The running gear includes a Meritor MX810 front axle, a ProTec Series 50 rear tridem, Michelin XZY3 445/65R22.5 tires, front disc brakes, and rear S-cam drum brakes. Electrical output is rated at 24 volts and 275 amps, and fuel capacity is 100 gallons. These details place the M917A3 between a civilian construction truck and a purpose-built tactical vehicle: it retains commercially derived components for maintenance and parts support, but the 8×8 driveline, reinforced frame and axle arrangement are intended to carry heavy loads where road surfaces are incomplete or damaged.

The truck has no standard organic armament. Neither the Army’s procurement description nor Mack Defense’s published configuration identifies a ring mount, remote weapon station, machine gun or firing port, so the M917A3 should be treated as an unarmed engineer truck whose protection depends on its armored cab, route security and accompanying combat units. The armor package is nevertheless more substantial than the term “commercially based” might suggest. Army budget documents state that the truck can be procured with protection meeting Long-Term Armor Strategy version 3.6 perimeter ballistic requirements and Mine Resistant Ambush Protected Capability Production Document version 1.1 underbody requirements. Live-fire testing conducted at Aberdeen Test Center from July 2019 through November 2020 included ballistic coupon tests, examinations of welds and armor gaps, fuel-tank fire-suppression trials, and full-vehicle exposure to side and underbody improvised explosive devices and mines. The Director, Operational Test and Evaluation, reported that the armored truck achieved the expected survivability against the tested kinetic threats, while detailed threat levels and residual vulnerabilities remained classified.

The operational value is measurable in hauling capacity rather than firepower. The 115 trucks could theoretically move 3,105 tons in one fully loaded fleet cycle, before accounting for maintenance availability, terrain, loading equipment, and travel distance. Compared with the 22-ton payload of the M917A1 and M917A2, the 27-ton rating represents a 22.7 percent increase per load. Moving 2,700 tons would therefore require 100 maximum-payload trips with the M917A3 against approximately 123 trips with a 22-ton truck, reducing the requirement by about 23 truck movements. That reduction has direct tactical consequences: fewer vehicles enter exposed road sections, fewer drivers and escorts are required for a given quantity of material, and engineer units can complete runway, road, or protective-earthwork tasks in less time.

The procurement case is driven largely by fleet age and force structure. The Army’s fiscal year 2027 justification identifies an acquisition objective of 1,029 trucks and states that the M917A3 replaces F5070, M917, M917A1 and M917A2 vehicles, with the oldest version in service for more than 50 years. The same document requests $17.03 million for 31 trucks in fiscal year 2027 and assigns them to active Army, Army National Guard and Army Reserve units; it explicitly connects the purchase to armored brigade mobility, countermobility and survivability during large-scale combat operations. Horizontal construction companies, equipment-support platoons, asphalt teams, and quarry teams use these trucks to move material for main supply routes, helicopter landing zones, airstrips, motor pools, and logistics areas. Those are recurring, tonnage-intensive tasks, and they cannot be substituted by lighter tactical trucks without increasing trip numbers and construction time.

Mack produced the 500th M917A3 in March 2025 under the original 2018 firm-fixed-price contract, which had a ceiling of $296 million for up to 683 trucks; by August 2025, the U.S. military had ordered 549. The follow-on contract preserves production after the initial agreement, but its 450-truck ceiling is an ordering limit, not a funded commitment, leaving annual appropriations to determine how quickly the Army approaches its 1,029-vehicle objective. For Congress, the relevant measures are therefore not only the number ordered, but delivery rates, armored-cab quantities, operational availability, cost per truck, and whether engineer units receive enough vehicles to retire the oldest fleets rather than operating two generations in parallel.

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