Staff Writer (Updated: 6/1/2016):
As war engulfed the European landscape in the early 1940s, American warplanners were keen to developments in the theater, particularly as to how they related to the advancing ground war. Nazi Germany's army made clever "lightning" use of their mechanized forces in conjunction with air support and paratroopers and would go on to conquer half of Europe in the process. Key to its successes were the light reconnaissance brigades that would often move ahead of the main force, collect intelligence and reconnoiter locales and deliver pertinent mission information back to HQ in preparation for offensives. As such, when drawing up specifications for their own light armored reconnaissance vehicle, the Americans took into account these qualities and related tactics to flesh out a new scout car.
In October of 1941, the US Army laid out formal specifications calling for a new armored vehicle to be built from a wheeled chassis and mount a 37mm main gun armament. Proposals numbering four were then received and two were selected for further development - one from Chrysler (Fargo Division) and the other from competing carmaker Ford. Both designs utilized a 6x6 wheeled chassis and fitted a 37mm main gun. The Chrysler attempt was built upon a 6x6 truck-type chassis to which the US Army designated as the "37mm GMC T23". The Ford concept was designated as the "37mm Gun Motor Carriage T22" and incorporated a hull-mounted machine gun.
Ultimately, the Ford T22 proposal won out though the Army requested several design changes prior to serial production. These included a reworking of the front hull hatches for the driver and passenger in addition to side armor wheel covers. The hull-mounted machine gun was removed altogether. The resulting changes produced the T22E2 pilot vehicle and the formal production designation became "Light Armored Car M8" in May of 1942. Initial production called for 5,000 vehicles and this total was then raised to 6,000 as the battlefield need for such a vehicle grew across Europe and beyond. Within time, procurement totals ballooned to include a further 5,000 examples with the first M8s leaving Ford assembly lines in March of 1943. By November of that year, over 1,000 vehicles had already been supplied to the US Army.
Like other American armored vehicles (and some aircraft) of the war, the M8 was first utilized in the hands of the British Army and, like other armored systems before it, it was they who bestowed the M8 with its well-known nickname of the "Greyhound" due to its form and function. The British - using recent combat experiences - were quick to not the type's thinly protected underbellies and felt their M8s too thinly armored for the role. Regardless, the type was used in number and also passed to Commonwealth allies in Australia and Canada.
Externally, the M8 Greyhound became one of the most recognizable vehicles of the entire war. The major design characteristic was its six-wheels, fitted three to a vehicle side, divided into one forward axle pair and two axle pairs at the rear. The glacis plate was well sloped to provide for basic point defense ballistics protection while the sides of the vehicle were near-vertical facings with the upper portions of the road wheels (optionally) covered over with thin armor. Aft of the glacis plate were two hinged hatches for the driver (seated left and a passenger (seated right). The hull roof was flat to which a rounded, open-air turret system was installed. The turret was fitted amidships in the design and provided a 360-degree arc of fire through manual, hand-powered traversal. Antennas were fitted ahead of the rear-mounted engine compartment and aft of the turret emplacement along the turret roof edges to help facilitate communications. The complete crew complement was four personnel to include the driver, vehicle commander, gunner and loader/machine gunner/radio operator. Armor protection ranged from 0.1 inches to 0.7 inches across the vehicle's various facings. Rear view mirrors, fitted atop thin extension supports at the front corners of the vehicle, aided the driver in rearwards maneuvers. Headlamps ahead of each front hull hatch were shrouded over in steel cages for basic environmental protection.