A Howitzer Motor Carriage based on the M5
The large-scale production of the M5 Stuart quickly led to several variant prototypes, including self-propelled artillery. One of these projects was a Howitzer Motor Carriage, equipped with the regular ordinance 75 mm (2.95 in) howitzer used throughout the war by the US Army and the Marines Corps.
The basis for this vehicle was the M5 Light Tank chassis, with its turret removed and replaced by a new open-top model, larger, with a short-barrel 75 mm Howitzer M2, equipped with 45 rounds of ammo. This prototype was named T17E1 HMC. The M2 howitzer, a more advanced version of the compact M1A1, was eventually replaced by the M3. Ammunition included M89 smoke shells and regular M48 HE (High Explosive) antipersonnel rounds. The only other weapon on board -besides the personal guns of the crew- was a Browning M2HB cal.50 (12.7 mm) machine gun mounted on the turret rear, intended for anti-aircraft defense, with 400 rounds.
The M8 Scott in production
The tests done in March 1942 with the T17E1 HMC were all satisfactory, and the first batch was ordered in April. Production was scheduled for September. In all, 1778 were produced until January 1944. Official designation was Howitzer Motor Carriage (HMC) M8, but it quickly received the “Scott” nickname. There were few differences compared to the M5. The hull was identical, although without the forward hull cal.30 (7.62 mm) mount. The extra space was used to store more howitzer rounds. Since the arc of fire of the 12.7 mm (cal.50) machine-gun was generous, it was also used as an antipersonnel defense gun, with devastating effects. However, the HMC was never intended to fight on the first line.
M8A1, The Main Variant
The M8A1 was the only variant, based on the M5A1 chassis, including all its features. The M5A1 hull was kept unchanged, except that a fixed hatch was mounted instead of the cal.30 (7.62 mm) mount. The motor was still the twin Cadillac V8 with hydramatic transmission. However, the M2 howitzer was replaced by the improved M3 version. Some M8s were equipped with side protection panels, and extra equipment, including camouflage nets. Others had a frontal “Culin Hedgerow Cutter” rake for jungle-clearing.
More M8A1s were produced than M8s, but all development stopped when the M7 Priest became available in numbers. M8 turret production didn’t stop, and many were allocated to the support version of the LVT, which fought mostly in the Pacific.
The M8 and M8A1 in Action
Contrary to the M5, which was allocated to Commonwealth and British forces under the name of Stuart Mk.VI, the M8 was mostly used by the US Army and Marine Corps. The Howitzer Motor Carriage fought with various artillery battalions in almost all Western theaters of war after its introduction, in Italy, Normandy, Germany, but also in the Pacific.
An M8 conducting fire – Photo: live.warthunder.com
The Free French received some of them, but after the war. These saw extensive service until 1954, during the Indochina conflict. Some were also employed by the South-Vietnam forces as far as the end of the Vietnam war. Some were used also by the Khmer national army, Laos and China. The Philippines also operated all M8s left on the island after WW2.
75 mm Gun Motor Carriage M8A1
In an attempt to give the M8A1 more anti-armor capabilities, development began on mounting the 75 mm Gun M3, as found on the M4 Sherman, into the turret with a new thicker mantlet. The idea was to create a fast, lightweight tank-destroyer that could exploit an opening, open fire, then retreat. The fast and small M5/M8 chassis was seen as a perfect candidate. Despite this, the project was canceled, as the M18 Hellcat was looming on the horizon.
The 75 mm Gun Motor Carriage M8A1 prototype – Photo: Wargamming.com
HMC M8 Scott in Normandy, July 1944. In the bocage, enemy troop movements were sometimes so hard to detect that M8 battalions found themselves attacked by infiltrated German infantry, in normally “cleared” sectors, but could repel assaults, thanks to their cal.50 (12.7 mm) machine-guns.
An M8 with a “Culin Hedgerow Cutter” rolls past a knocked out Panther A at St Gilles, France, 1944.
M8 Scott at the Saumur Museum – Credits: Wikipedia.
HMC M8A1 Scott specifications
|Dimensions (L-w-h)||14.3x 7.5x 8.8 ft (4.4x 2.3x 2.7 m)|
|Total weight, battle ready||16.33 tons (32,600 lbs)|
|Crew||4 (driver, commander, gunner, loader)|
|Propulsion||Twin Cadillac V8 16 cyl
220 hp, hydramatic transmission
|Speed||36 mph (58 km/h) on-road
18 mph (29 kph) off-road
|Range||100 mi (160 km at 30 km/h)|
|Armament||3 in (75 mm) M2/M3 howitzer
Cal.50 (12.7 mm) Browning M1920
|Armor||From 0.3 to 1.7 in (9.5 to 44 mm)|
Links & Resources
The M8 Scott on Wikipedia
Osprey Publishing, New Vanguard #33, M3 & M5 Stuart Light Tank 1940–45