Mack NO

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Mack NO series
Mack NO-6.JPG
Mack NO-6 truck; Overloon War Museum, Netherlands
Type 7 12 ton (6,803kg) 6x6 Prime mover
Place of origin  United States
Production history
Manufacturer Mack Trucks
Produced 1943-1945
Number built 2,050 (total all models)
Variants NO2, NO3, NO6, NO7
Specifications
Weight 29,103 lb (13,201 kg) empty
Length 297 in (7.54 m)
Width 103 in (2.62 m)
Height 124 in (3.15 m)

Engine 159 hp (119 kW)
Transmission 5 speed x 2 range trf. case
Suspension Beam axles on leaf springs
Operational
range
400 mi (643.7 km)
Speed 32 mph (51 km/h)

The Mack NO was a heavy 6x6 cargo truck designed in the 1940s by the American manufacturer Mack Trucks. It was used by the U.S. Army as an artillery tractor for heavy artillery during and after World War II. The official U.S. Army designation was: Truck, 7 1/2 ton, 6x6, Prime Mover.[1] It’s G-number was (G-532).

History[edit]

In 1940 Mack Trucks started the development of an artillery tractor for the U.S. Army, with a payload of 7 12 tons (6,803kg), to tow the 155mm “Long Tom” field gun, the 8 inch howitzer, and the 240mm howitzer.[1] A contract for the production of the vehicle was awarded in September 1940, and in January 1942 a vehicle of the NO-1 type towed the first 240mm howitzer carriage from the Bucyrus plant in South Milwaukee, Wisconsin to the Aberdeen Proving Ground test facility.[1]

The NO-1 was the first in a series of five very similar prime mover vehicles. The NO-2 differed in details, among them a canvas cabin roof (the NO-1 had a metal roof) and the winch behind the front bumper (above the bumper in the NO-1). A total of 403 units of the NO-2 were delivered in 1943.[1] The next prime mover models, which marginally differed from the NO-2, were the NO-3 and NO-6. A total of 1,097 units of these were ordered and delivered in 1943 and 1944. The last of the series was the NO -7 model, of which 188 were delivered in 1944 and 362 in 1945. Several NO-7 were provided after the war to the European armies being rebuilt, including those of United Kingdom, France, Belgium and Netherlands.[1][2]

The models NO-4 and NO-5 were prototypes of heavy salvage vehicles, equipped with a Gar Wood crane which could swivel to the left and right. Neither model was put in production.[1][2][3]

Description[edit]

Mack NO towing a gun; War and Peace show

The vehicle had a typical configuration, with a hooded front engine behind which was a large driver cabin that could seat five soldiers, and a rear cargo area.

The engine was a Mack EY, 6-cylinder gasoline with a displacement of 707 cu in (11.6 L) ; generating 159 hp (119 kW) at 2100 rpm and 534 lbf·ft (724 N·m) at 800 rpm. [1] The transmission had 5 gears forward and one reverse. The installation of a transfer case with an additional reduction gear allowed high and low gearing (5F1Rx2).[4][5]

Traction was in all six wheels (6x6), with 14.00-24 tires. The empty weight of the vehicle was 29,103 lb (13,201 kg) when empty, and 44,453 lb (20,164 kg) fully loaded.[1][4][5]

The gas tanks were located on both sides of the vehicle, with a total capacity of 170 US gallons (640 l; 140 imp gal). At the front of the vehicle a Gar Wood winch was installed with a pulling capacity of 40,000 lb (18,000 kg). It could be used to assist in placing the gun, or to help moving the vehicle if it was stuck. [1][2][3][4][5]

The cargo area was 11 ft (3.35 m) long by 8 ft (2.44 m) wide and could carry 7 12 tons (6,803kg) of cargo. Starting with the NO-2 model, at the rear of the cargo compartment a small crane was installed to assist in in placing the gun.[1]

Variants[edit]

In total 2,053 Mack NO vehicles were built, in 7 variants as described in the following table.[1][2]

Type Model Years Produced Number Built
Artillery tractor NO-1 1
Artillery tractor NO-2 1943 403
Artillery tractor NO-3 & NO-6 1943 to 1944 1,097
Salvage vehicle NO-4 1
Salvage vehicle NO-5 1
Artillery tractor NO-7 1944 and 1945 550 (188 + 362)

See also[edit]

References[edit]

  1. ^ a b c d e f g h i j k Vanderveen, Bart (1998). A Record of Military Macks in the Services and Beyond. Wheels & tracks. After the Battle. pp. 79–87. ISBN 1-870067-09-6. 
  2. ^ a b c d Doyle, David (2003). Standard catalog of U.S. Military Vehicles. Kraus Publications. pp. 213–215. ISBN 0-87349-508-X. 
  3. ^ a b Ware, Pat (2010). The World Encyclopedia of Military Vehicles. Lorenz Books. p. 241. ISBN 0-7548-2052-1. 
  4. ^ a b c "TM-11-1679 Maint. manual for Mack Models NO2, 3 & 6 7 12 ton, 6X6, Prime Mover". US Dept. of the Army. Apr 1943. Retrieved 11 Dec 2014. 
  5. ^ a b c "TM-9-2800-1947 Military Vehicles". US Dept. of the Army. 27 Oct 1947. Retrieved 11 Dec 2014. 

External links[edit]