Saturday 12 November 2016

Vickers E: Bestselling Export

The late 1920s were a dark time for British tank building in general and the Vickers company in particular. Sir George Thomas Beckham, the company's chief designer, died on May 9th, 1928. Order for new tanks began to decrease. New designs, the A1E1 Independent and A6 Medium Tank, were unsuccessful. Meanwhile, Vickers received their first overseas order, selling a Medium Tank Mk.C to Japan. The next foreign sale was a Medium Tank Mk.D to Ireland, plus the Medium Tank Mk.II piqued the interest of some foreign buyers.

This pushed the company, united with Sir W.G. Armstrong Whitworth & Company into Vickers-Armstrong Limited in 1927, to work on creating tanks purely for export. The result of this work was the Vickers Mk.E, a tank that cemented its creators and the Vickers company in world tankbuilding history.

New Blood

After the end of WWI and the inevitable downsizing of the armed forces, British officers were left without the ability to make a career in the military and decided to proceed in different directions. Some of them tried their hand at the automotive industry. Captain John Valentine Carden was among them. He worked with small cars before the war and on sport cars after, but failed to reach success in this field.

Another British Army Captain, Vivian Graham Loyd, had the same hobby. The two talented engineers met in 1923. Together, they decided to leave the automotive industry, already oversaturated with small companies, and begin producing military vehicles.

Suspension element designed by John Carden and used widely on Vickers tanks.

The Carden-Loyd company opened for business in 1925. Like Giffard Le Quesne Martel, another key figure in British tank building, Carden and Loyd tried to make a one-man convertible drive tankette. After three prototypes, they shifted their efforts to two-man Carden-Loyd Mk.IV and Mk.V tankettes.

The result was an outstanding vehicle, the Carden-Loyd Mk.VI, which sold an enormous 450 units. Carden and Loyd's creation raised the bar for tankettes as a class and served as a starting point for tankette designs in many countries. Aside from other features, the tankette was the first mass production armoured vehicle to have the transmission in the front of the hull.

Experimental prototype of the 6-ton Vickers tank with a Dorman engine.

Aside from building tankettes, Carden-Loyd offered engineering consulting services. In 1926, they began working closely with Vickers, a relationship that proved very constructive and mutually beneficial. The small company was protected by the arms giant, and in turn Vickers-Armstrong received Carden-Loyd's prospective designs.

The most interesting of them was a suspension designed by John Carden. He designed a balancer system with rather large road wheels and leaf springs. The system proved useful on light tanks.

Carden designed another balancer suspension. It used the four-wheel system (two bogeys with two small road wheels on each) with half-leaf springs. Thanks to this layout, light tanks received 8 wheels per side, which was good for a tank that would be mostly used off-road.

Carden's suspension was compact and easy to service. If necessary, this suspension could be serviced by a mechanic of below average skill. Now came the hard part: making a tank with this suspension.

Small Triplex

The development of a new light tank was complicated by the fact that the British army did not need it. At the time, British mechanized force theory contained heavy tanks (A1E1 Independent) as breakthrough vehicles which supported medium tanks with cannon and machinegun armament (Medium Tank Mk.I and Medium Tank Mk.II). The third link in this chain was tankettes (Carden-Loyd Mk.VI). There was no room in this system for light support tanks like the Renault FT. The only solution was to export the tank.

The tank also served as a base for an artillery tractor.

Even though the words "Carden-Loyd" are absent from the name of the tank, it would not be possible without the company. Carden-Loyd was responsible for not only the suspension, but the overall layout of the vehicle. It was based on the Carden-Loyd Mk.VI, but the engine was moved out of the fighting compartment and into the rear.

The tank was powered by an 80 hp water-cooled Dorman engine, widely used by various automotive companies. The driver was placed to the right of the tank. Initially, his hatch contained 5 whole sections. The turret platform was made removable as well.

Artillery tractor with an Armstrong-Siddeley engine.

The experimental tank, initially called 6-ton Experimental Vehicle, was armed in an unusual manner. Usually, light tanks of the time had a one-man turret with a machinegun or a small caliber cannon. This new tank had two turrets, and both were equipped with Vickers machineguns.

This layout revealed the purpose of the tank. Vickers engineers envisioned it as a "trench sweeper". Thanks to two turrets, it could fire in two directions simultaneously. If necessary, the turrets could concentrate their fire on a target behind or in front of the tank. With a mass of 6 tons and a three man crew, the tank had the same protection and speed as the Medium Tank Mk.II.

The name "Vickers-Armstrongs 6-ton Tank" was used officially.

An artillery tractor was designed on the same chassis. The "recipe" for making one was simple: the turret platform and turrets were removed, a windshield was installed in front, and seats were installed in the fighting compartment.

VIckers-Armstrong engineers decided to try out their own engine in this design. The Armstrong-Siddeley engine was air cooled. It was an ordinary linear four-cylinder engine with the same power output as the Dorman, but with a twist. In order to reduce the height of the engine compartment, the designers put their engine in horizontally, covering it with an oil radiator. As a result, the engine compartment's height was greatly reduced.

Trials with the experimental tractor proved that the idea worked, and the use of the Dorman engine was discontinued. By 1929, the tank design was finalized. By then, the suspension and track links were slightly changed as well. Carden and Loyd's design was truly revolutionary. The tracks lasted for 4800 km, which was fantastical for the time.

Vickers Mk.E Type A in its final form.

Two variants of the tank were made available to potential buyers. Aside from the official designation "Vickers-Armstrongs 6 ton tank" (Vickers 6-ton in the Russian variant), another index was used: Vickers Mk.E. Some conspiracy theorists decided that the E stood for Export, but this opinion is incorrect. The letter E follows the letter D, and the Vickers Medium Tank Mk.D already existed.

The basic version of the tank was the Vickers Mk.E Type A with two machinegun turrets. It had differently shaped turrets compared to the prototype and the machineguns were equipped with armoured shrouds. The "6-ton" designation was only partially true, as even in this form, the tank weighed 6.6 tons.

For an additional fee, the manufacturer offered to install a radio with an antenna behind the turrets, which decreased the ammunition capacity of the tank from 6,000 to 4,000 rounds.

A special trench-crossing device designed by Miklós Straussler.

This modification was the first tank that brought serious commercial success to Vickers-Armstrongs on the export market. In 1930, 15 tanks were ordered by a Soviet purchasing commission headed by the Chief of the Red Army Mechanization and Motorization Directorate, Khalepskiy. Each tank cost 4200 Pounds Sterling. It's doubtful that this deal made the Poles happy, who familiarized themselves with the tank back in 1927. In total, Poland bought 38 tanks.

Another Type A was sent to Greece, Bolivia and Portugal bought one two-turreted tank each. The Japanese and Americans also purchased one tank apiece with the goal of studying them. 58 tanks isn't bad, considering the worldwide financial crisis and the British military's hesitation about new purchases.

Vickers Mk.E Type B in the Kuomintang army.

A new version of the tank was put on the market in 1930: Vickers Mk.E Type B. The mass of this "6-ton" Vickers was over 7.2 tons. The main distinguishing factor was that the tank now had one turret, shifted to the right from the center axis, instead of two machinegun turrets. The turret was shifted so the turret crew did not interfere with the driver. This solution also ensured that the driveshaft from the transmission to the engine did not get in the way.

The 47 mm Vickers QF short barreled gun was placed inside the turret, along with a coaxial machinegun. Despite the humble barrel length, an armour piercing shell from this 3-pounder gun penetrated 25 mm of armour from 500 meters. This was enough to pierce almost any tank from the period, including the French Renault NC, which was also available for export. The 47 mm gun also had high explosive ammunition, which was unusual for a British tank of the time.

Tanks from the third series with a turret bustle for the radio.

Around this time, a very specific variant of the tank called Vickers Mk.E Type C was potentially offered to customers. It was a Type A, but with 37 mm AT guns installed in the front and rear of the hull. However, since not even a diagram of this tank survives, there is a suspicion that the tank only existed in someone's imagination. Another clue against the existence of this tank was the fact that 37 mm guns were not used in British tanks.

Export Variants

The Greeks were the first to order the Vickers Mk.E Type B in August of 1931. The Bolivians were next, buying two tanks. Siam received another two, and Finland and Portugal bought one each.

This was only the beginning compared to what happened in 1934. Vickers-Armstrongs obtained a large new client: China. The first 12 Vickers Mk.E Type B tanks were ordered in March of 1934. In total, 20 tanks in three series were ordered. Starting with the second series, the tanks received a turret bustle for a radio station. 8 more Type B tanks were ordered by Bulgaria. In addition, Poland bought 22 turrets to convert tanks purchased earlier.

Vickers Mk.F on trials.

Meanwhile, Vickers-Armstrongs engineers did not sit still. With all the advantages of an air-cooled engine, it had one drawback: overheating. The limited space in the engine compartment resulted in difficulties with cooling.

A simple, but radical, solution was to replace the engine. A new engine was found relatively quickly: the Rolls-Royce Phantom II. It was impossible to fir the 7.67 L 6-cylinder engine in the existing engine compartment, so the designers had to use a few tricks. The engine was placed into the fighting compartment, which forced the turret to shift to the right and as far back as possible to not interfere with the driver.

An air intake was also added in the front of the hull, from the left side. The muffler migrated from the rear to the left side of the turret platform.

Cutaway of the Vickers Mk.F. The difference in layout compared to the Mk.E is easy to see.

In 1934, the experimental tank, indexed Vickers Mk.F, was trialled by the Belgians, for whom it was initially made. The customers were not thrilled by the presence of a large, loud, and hot engine in the fighting compartment, especially when the cooling of the new engine still left much to be desired. The air intake in the front of the hull also made a perfect target. The Belgians rejected the Vickers Mk.F.

Vickers-Armstrongs found an alternative which suited the Belgians, but that's a whole different story.

A large air intake can be seen on the front.

Despite such a sad twist, the story of the Vickers Mk.F had a happy ending. The shape of the hull of this modification was considered fortunate, and put into mass production. The converted engine compartment could fit the Armstrong-Siddeley engine, and cooling was improved. The fighting compartment became roomier.

Finnish Vickers Mk.E Type B with a Vickers Mk.F type hull.

Tanks of this type were sent to Finland. On July 20th, 1936, the Finns ordered 32 Vickers Mk.E Type B tanks. These tanks are often confused for Mk.Fs, but these were Mk.E tanks with Armstrong-Siddeley engines. 12 tanks were ordered by Siam in 1938, but only 8 made it to the customer.

Second Time's the Charm

As mentioned above, the Vickers Mk.E had no place in the British army's system. Despite this, the army tested an experimental prototype of the tank and the tractor on its chassis. The two-turreted machinegun version did not impress the military, and neither did the price: a whole half of a Medium Tank Mk.II. Vickers didn't manage to sell the Type E to their own army. As with the Belgians, the British army was more interested in another lighter tank, also developed with participation from Carden-Loyd.

Mass production variant of the Dragon artillery tractor.

The failure of the Mk.E didn't mean that there was no room for Vickers' vehicles in the army. A list of improvements was proposed for the tractor that was tested in 1930. In 1932, a reworked artillery tractor indexed Vickers B12E1 came into existence. Moving the driver forward resulted in a much larger transport compartment, but this vehicle was also rejected.

Finally, another seriously reworked vehicle was offered: Dragon, Medium Mk.IV. Instead of an Armstrong-Siddeley engine it used a 90 hp AEC engine. Ammunition racks lined the sides of the tractor, and there were many changes to the transport compartment. The British army ordered 12 vehicles. The mass production versions of the Dragon were slightly different from the prototype. Their main purpose was the transport of 60-pdr (127 mm) guns.

This tractor was the only Vickers vehicle that really fought in the British army. In 1940, the tractors were sent to France as a part of the British Expeditionary Force, where they were abandoned after the evacuation in June of 1940. The Germans became their new owners.

In addition, 18 Dragons were ordered by India and 23 by China.

An SPG ordered by Siam was similar to the Dragon. 26 vehicles armed with 40 mm Pom-Pom autocannons were sent there.

Vickers Mk.E Type B in the 44th RTR. The tank has a WD number of 10677, and serial number V.A.E.1986.

Another story is associated with Siam. As mentioned above, the country ordered 12 Vickers Mk.E Type B tanks in 1938. 4 tanks, with serial numbers from V.A.E.1983-1986 never made it over. In June of 1940, when the BEF was forced to abandon most of its tanks in France, the military was forced to look for any vehicles to replace them. The four Vickers tanks meant from Siam were pressed into service. The tanks received WD numbers from 10674 to 10677 and included in the 44th Royal Tank Regiment.

The tanks served for the purposes of training until at least 1941. Britain, the birthplace of the tank, became the last one to adopt it into service. One of those tanks, V.A.E.1985, survived to this day and can be seen in the tank museum in Bovington. The tank is painted up in Chinese colours, even though it would have borne British tactical marks.

The Vickers Mk.E tank had an enormous effect on tank building worldwide. It became the starting point for the American Light Tank T1E4, the progenitor of most American tanks and SPGs built from 1933 to 1944. The tank had a similar effect on Japanese tank building. All Japanese tanks developed since the 1930s, including the Type 95 Ha-Go, were descendants of the British tank. The situation with Italian medium and even heavy wartime tanks was analogous. The British ancestry of the Polish 7TP and Soviet T-26 is already well known. It is shocking that, aside from a few pre-war light tanks, the Vickers Mk.E had almost no influence on British tank design.

Just one article is not enough to describe such an important tank as the Vickers Mk.E. Aside from its influence on tank design, the Vickers Mk.E fought the longest out of any interbellum tank. Its combat career began in 1933 and ended in the late 1940s. Future articles will tell of the fate of the Vickers Mk.E in the armies of various nations.


  1. "Despite such a sad twist, the story of the Vickers Mk.F had a happy engine."

    Is this supposed to say "happy ending" perchance?

  2. Nice blog, I really enjoy reading your posts!
    Vickers E was used in 1939 in Polish-German-Soviet war, and it served pretty well, it's cannon was just enough for anything Germans had at this point of war.

  3. Very interesting I worked at vickers Crayford in the 1960 as a photographer on most progects , my father also worked their 1920- 1970 as a toolmaker and was involved in many products mentioned in the Blog, R100 bouncing bomb etc