Before the outbreak of World War II France had bought in United States 210 Mack EXBX heavy trucks for transporting tanks.

[citation needed] The British Purchasing Commission acting in the United States contracted the provision of Mack heavy trucks for military use; this resulted in the NR series.

[1] These trucks were similar to those provided to the British troops through the French order, but were not specifically equipped for tank transport.

The NR-1 was a variant of a basic civilian version that was marketed in the 1930s by Mack; however with a solid grill to protect the radiator and headlamps, and an extra roof above the cab to prevent overheating.

The trucks were powered by a six-cylinder Mack-Lanova ED engine which could deliver 131 HP at 2,000 rpm; driving a TR 12 Duplex transmission with five gears.

Many copies of the NR-15 were shipped to Iran and played a key role in the transport of war materials to the Soviet Union via the Persian Corridor The two fuel tanks had a capacity of 280 liters (75 US-gallon) and were mounted on either side of the vehicle.

[1] In total, 16 548 examples of the NR series were produced,[1] and due to their good quality most remained in service until well after the war.

[citation needed] The vehicle had a typical configuration, with a hooded front engine behind which there was a large driver cabin, and a rear cargo area.