Beyond blueprints: Cruiser Mk I’s impact explored – specifications, variants, and historical operations

The Cruiser Mk I (A9) represented a historic moment in British tank design during the interwar period, emphasising speed and agility. Its descendant, the Cruiser Mk II, inherited the same characteristics while improving defensive capabilities.

The Tank, Cruiser, Mk I (A9) is an important milestone in British military history from the interwar period. As the first cruiser tank, it was a pioneering design aimed at gaining combat speed, allowing it to strategically traverse around major enemy lines. This distinct strategy enabled the Cruiser Mk I to effectively engage the enemy’s lines of communication while confronting opposing tanks with agility and speed.

Following the success and learning acquired from the Cruiser Mk I, the Cruiser Mk II seemed like a natural next step. This later generation, created almost concurrently, demonstrated a careful progression by introducing a larger armour profile. The Cruiser Mk II kept the core concepts of its predecessor while improving its defensive capabilities, demonstrating the versatility and responsiveness that characterised British tank development during this period.



With a fighting weight of 12.8 long tonnes (13.0 t), the Cruiser Mk I had compact dimensions, measuring 19 feet (5.8 m) long, 8 feet 4 inches (2.5 m) wide, and 8 feet 8 inches (2.65 m) tall. The tank was manned by a crew of six, comprising a commander, gunner, loader, driver, and two MG gunners, and had armour ranging from 6 to 14 millimetres, giving vital combat protection.

The Cruiser Mk I was equipped with a QF 2-pdr main armament and could carry up to 100 rounds, ensuring firepower in battles. In addition to its primary weapon, the tank included three 0.303 Vickers machine guns with a total ammunition capacity of 3,000 rounds, increasing its adaptability and ability to engage multiple targets.

The Cruiser Mk I’s propulsion system was powered by an AEC 179 6-cylinder petrol engine producing 150 horsepower (110 kW). Its spring triple-wheel bogie suspension improved mobility on varied terrains, enabling successful navigation across difficult terrain.

The Cruiser Mk I exhibited the ability to operate continuously, with an operational range of 150 miles (240 km). Its top speed of 25 mph (40 km/h) demonstrated its rapidity and response on the battlefield, making it a formidable presence during its time.


The 1st Armoured Division used the Mark I Cruiser tank, designated A9, in the Battle of France in 1940. Following that, the 2nd and 7th Armoured Divisions used the Mark I during the North African campaign until 1941. This early prototype demonstrated the developing design and deployment of cruiser tanks during World War II, exemplifying the British military’s strategic adaptations to different theatres of war.

The Mark I CS was a modified version of the Mark I, distinguished by its armament. Instead of the 2-pounder cannon, the Mark I CS was outfitted with a 3.7-inch (94 mm) /L15 breech-loaded howitzer, which was directly adapted from the QF 3.7-inch mountain howitzer used during World War I. This modification represented the Mark I platform’s adaptability by allowing the insertion of various artillery pieces to meet varied combat requirements. The Mark I CS carried 40 rounds, the majority of which were smoke projectiles, demonstrating its intended usage as smoke cover and support in a variety of tactical scenarios. This version improved the Mark I’s adaptability to a variety of strategic missions, demonstrating the British military’s commitment to innovation and flexibility in the early stages of World War II.


The Cruiser Mk I, sometimes known as the Mark I cruiser, began deliveries in January 1939, with a total of 36 tanks delivered before the onset of World War II. Another 40 tanks were delivered between September and December 1939, followed by 49 more in 1940. This British tank was useful in a variety of campaigns, particularly in the French, Greek, and early North African theatres.

Throughout the North African campaign, the Cruiser Mk I demonstrated its combat abilities. Its 2-pounder cannon proved effective against early Italian tanks encountered in the desert. The tank could hold its own against General Erwin Rommel’s early Panzer II and III tanks. Furthermore, the 2-pounder cannon could penetrate the protective steel armour (20-30 mm) of opponents such as the Panzer III Ausf D and Panzer IV Ausf D. However, its efficacy declined once the Germans introduced the more strongly armoured Panzer IV Ausf E in the spring of 1941.

Despite its fighting capability, the Cruiser Mk I encountered severe obstacles. The tank’s thin armour made it vulnerable to Axis anti-tank guns. In addition, the absence of high-explosive ammunition for the 2-pounder cannon and armour-piercing shells for the 94 mm gun on the close support version posed operational challenges. The design issue surrounding the front machine gun turrets enhanced the Cruiser Mk I’s frontal susceptibility to opposing fire, giving it a strategic disadvantage.

The Cruiser Mk I also suffered from mechanical unreliability. The tank struggled with its tracks, which were immediately slewed, reducing the vehicle’s overall operating effectiveness. These operational issues, combined with the changing character of armoured warfare and the introduction of more advanced German tanks, all contributed to the Cruiser Mk I’s declining importance on the battlefield.