In 1939, when British soldiers went to France, there were three types of carrier; the Bren Carrier (the most common type) which mounted a Bren Gun as main armament, the Scout Carrier (with room for an extra man or a No.11 Wireless Set in addition to a weapons mount in the rear compartment for either a Boyes anti-tank rifle, or an additional Bren Gun) and the Cavalry Carrier (intended to carry six soldiers, under armour, with the ability to keep up with fast moving tanks). The concept of a Mobile Division, in which the Cavalry Carrier was envisioned to operate, was evolved into the Armoured Division, and the need for Cavalry Carriers disappeared - only 50 were built.
After the Battle of France, carrier development was rationalized, into a Universal design, and the Universal Carrier Mark I was born. The Universal Carrier had more armour than the previous Bren and Scout designs, including bulletproof protection for the engine. Mudguards and crew steps were added to the hull sides, and a compartment for extra stores or passengers was added behind the driver.
The Universal Carrier Mark II had a permanent mount for a 2-inch Mortar, as well as a welded waterproof hull. The Mark III was similar, with a modified air inlet and engine cover.
All types of Universal Carrier were only lightly armoured, which made it proof against small arms fire though not close-range machine gun fire. Carriers weighed just over 4 tons, and several variants both official and unofficial were developed to mount a variety of weapons including the 3-inch Mortar, 4.2 inch mortar, and Vickers Gun, with field fittings of Browning machine guns and even PIATs also seen. The Wasp was a purpose built variation that carried a tank of fuel (jellied gasoline, later popularized as 'napalm') and a flame projector that was greatly effective against soft targets.
The carrier had an 85 horsepower engine (later replaced by a 95 horsepower engine) that could drive the vehicle 30 miles per hour. The carrier was small, being just over 5 feet tall, almost 7 feet wide, and between 12 and 13 feet long.
Canadian units arriving in the United Kingdom in 1939-40 found shortages of all types of vehicles; Canadian-made universal carriers did not arrive until 1941. At the end of Aug 1941, Canadian units in the UK had need of 730 carriers with only 519 on strength. Canada at that time was using Univeral Carriers instead of the specialized Mortar Carrier and Observation Post Carriers called for in divisional War Establishments. At the end of Aug 1943, some 2,359 Canadian-made Carriers were on strength, with 143 British-made Carriers in Canadian units. Powerplants were a mixture of 95-horsepower motors, and older 85-horsepower motors. By the beginning of 1944, 3,888 Canadian-made Carriers were on strength, against only 72 British-made.
The Loyd Carrier was developed from 15-cwt Fordson truck, using that vehicle's engine, radiator, gear box transmission tube and differential, with two sets of double-bogie suspension units as used on the Universal Carrier. Steering was done by stopping one track and was not as sophisticated as the Universal Carrier. The Loyd was originally intended as a personnel carrier but evolved into other roles. Total production would eventually reach 26,000 vehicles, with only two main variants; the Mark I and the Mark II, the main difference being the type of brakes used. As production went on, various engines were used, without change to the designation of the vehicle. Canada did not produce Loyd Carriers, but did utilize them, primarily in infantry battalions to haul the 6-pounder Anti-Tank Gun of the Anti-Tank Platoons, though far more common was the Universal, T-16 or Windsor for that role.
Another role filled by the Loyd was as a Slave Battery Carrier (officially designated the "Carrier, Tracked, Starting and Charging" for "slaving" (or jump-starting) other vehicles in cold weather or when batteries had died. The vehicle had both a 30 volt and 12 volt generator.
T-16 and Windsor
As weapons and tank development increased the need for larger anti-tank weapons in infantry and anti-tank units, the requirement for a carrier able to haul the larger guns and ammunition led to the development of large carriers.
A Canadian-built variation called a "Windsor" had a lengthened body (and is identifiable by the double sets of road wheels); the American-built T-16 was also a variation on the Universal Carrier that was recognizable by a longer body and extra road wheels.
The "Vehicle Data Book" released by the Canadian Army (Overseas) in March 1944 lists several variants in use at that time:
By 1944, the roles of the Universal Carrier included the previously mentioned uses by infantry and motor battalions, by reconnaissance regiments for armoured recce missions on a divisional front, as liaison and Observation Post vehicles in artillery units, as gun tractors in anti-tank regiments, and to ferry recovery tackle (for the D-8 tractor) in RCEME units.
Each vehicle officially carried one Bren Gun, a machine carbine, and three rifles. Commander's carriers had wireless transmitter sets.
Carrier, 3-inch Mortar
Mortar carriers were used in infantry battalions, motor battalions, and reconnaissance regiments. Each vehicle was equipped with a 3-inch Mortar, which could be fired from the vehicle or from the ground using the base plate which was normally stowed, as well as five rifles. Communications gear might include a Telephone Set D Mk. V and/or a No. 18 wireless set, as well as two No. 38 wireless sets (small, man-portable radios).
Carrier, Universal, T-16
The T-16 was the preferred vehicle for Anti-Tank regiments and Anti-Tank platoons of Motor battalions and infantry battalions, being used as both a gun tractor (for either the 6-pounder Anti-Tank Gun or the 17-pounder Anti-Tank Gun, with two additional carriers for each platoon of four guns carrying ammunition. Gun tractors had a crew of 5 (including the gun crew) and ammunition carriers a crew of 3, two of whom were also gun crew members.
Carrier, 4.2-inch Mortar
The 4.2-inch Mortar carrier was a modified T-16, used by machine gun battalions in infantry divisions and independent machine gun companies in armoured divisions. The mortar was always fired from the ground and the carrier used only to move the weapon from place to place.
Carrier, Universal (Windsor)
The tactical role of the Windsor was the same as that of the T-16, moving ordnance and support weapons along with ammunition and crew members.
From early on, infantry (rifle) battalions in the Second World War were equipped with a Carrier Platoon of 13 vehicles. As well, the Mortar Platoon and Anti-Tank Platoon in infantry battalions were also normally equipped with carriers. Infantry (Motor) Battalions and Infantry (MG) Battalions also used carriers, as did units of the Royal Canadian Artillery.
Aside from the Motor Battalions in Armoured Divisions, the armoured brigades also used Slave Battery Carriers (SBC) to "slave" (jump start) tanks in cold weather.