The early 1920’s were a difficult time for the British Royal Armoured Corps (RAC). Their First World War tanks were becoming worn down and obsolete. Equally, a series of projects designed in house, such as the Medium D, Medium C, and Light Infantry tank, had all failed. Other external designs such as the Vickers No.1 design had failed to be taken up.
This was a major issue to the RAC as the Treasury had provided a sum of GB£220,000 for the purchase of tanks to totally re-equip the RAC. If, however, a new tank could not be found then this money would be reclaimed by the Treasury, and any new purchase of equipment would be subject to new reviews. These would push the acquisition of new equipment back by years and leave the RAC with its First World War Mk.V Tank and Medium A Whippets well into the late 1920’s.
Then, in 1923, the army received two new tanks. Although unarmored, these tanks were the forerunners of a design that would see service all the way until at least 1941. These two tanks were the first of the Vickers Medium Mk.I, and almost no clue can be found to their origin. David Fletcher (Mechanised Force, p.8) suggests these tanks may have been created out of spare parts and designs lying around by Vickers in collusion with the War Office.
The only other clue might come from a copy of The Commercial Motor magazine of October 1933. In an article talking about a tractor, the designer of the tractor is introduced as Mr. C. S. Vincent-Smith, whom it is claimed designed tanks for the Army. This is the only tenuous link to the creation of the Mediums.
Medium Mark I Design
The first two tanks (one with the registration T15) were designated A2E1, Tanks, Light, Mk.I. Later, as the design improved, the tanks were renamed to Tanks, Medium, Mk.I. Today, they are usually called the Vickers Medium Mk.I. A short time later, in 1923, a single A2E2 arrived. This was named ‘David’ and had the registration T18. It was the only Close Support (CS) Mk.I variant ever built. Uniquely, it also mounted the sole 15-pounder tank mortar prototype.
The Close Support tanks were designed to fire smoke shells to cover the advance of friendly armor and protect them from enemy anti-tank guns. During this period, the weapon chosen was a 3.7” weapon that could only fire smoke. No other working round was produced. Although several other types of shell were designed, or designated, in effect the 15-pounder only ever had smoke shells.*
*For a complete story on the 15-pounder tank mortar, and its shell types see: Forgotten Tanks and Guns of the 1920’s, 1930’s and 1940s, ISBN 9781-5267-14534, By David Lister.
Mk.II* CS tank. Photo: SOURCE
On the gun tanks, the circular turret mounted a 3-pounder Mk.I, L32 gun, with a Hotchkiss machine-gun in a separate ball mount to the right of the turret. A visually distinctive feature of British armor of the time was the bevelling of the turret sides. The turret had three ball mounts for Hotchkiss machine-guns.
Two of these were placed about 180 degrees apart with the first one a few degrees to the right of the main gun. The third was placed on the aft right quarter of the turret. This meant that to bring a machine-gun to bare on a target to the front the 3-pounder had to be slewed off to one side. Two additional Vickers machine guns were mounted, one on either side, in the hull.
The V8 Armstrong Siddeley engine was mounted in a chamber separated from the rest of the fighting compartment on the left of the hull, with the driver sitting beside it. The driver’s head was in a cowl with a D shaped front plate that opened sideways. This plate hinged on the right side of the cowl, and mounted vision ports allowing the driver a view to the front, but was not intended as an entry or exit route. The rear plate of the hull mounted a large door on the right. This, along with two smaller hatches just in front of the Vickers guns, provided entry and egress to the crew.
Crew entering a Mk.IA*. Of note is the counter-weight on the back left of the turret, and the plated over opening of the third Hotchkiss machine gun location to the right of the counter-weight. Photo: SOURCE
Evolution of the Medium
The Medium went through several variants and two marks during its life. Often, these can seem confusing at a first glance. Identification is not made any easier by the fact that some components were retrofitted to earlier marks outside of the following official designations.
As the Vickers Mediums are a complex subject with many submarks, this is a simple identification guide. First, it has to be determined if the vehicle is a Mk.I or a Mk.II. The three easiest ways of identifying this is to look at the tracks, front hull or main gun.
The clearest item is if the bogies are exposed or covered.
Notice the shape and how the front hull looks bulkier and bigger on the Mk.II. Also, on the Mk.I, the roof of the driver’s hood is roughly in line with the roof of the rear part of the hull.
The 3-pounder Mk.I has a shorter, stubier looking barrel. However, the easiest way of telling the two apart is the recoil recuperator (the tube under the gun barrel). On a 3-pounder Mk.I it sticks out much further, while on the 3-pounder Mk.II it is contained almost wholly within the turret.
The following image illustrates the differences between the driver’s hood for the Mk.I (left) and the Mk.IA and subsequent marks. On the Mk.I the entire hood is hinged upwards. On the later marks the hood is split into three parts, with the roof folding back and the sides folding outwards.
The ‘Bishops Mitre’ is the triangular shaped cupola that was added to the commander’s position. In the earlier tanks there was a simple two piece hatch. It was located further to the rear of the turret roof.
This image shows the bevel at the back of the turret that was introduced in the Vickers Mk.IA, and seen on the rest of the Mk.I series and the first Mk.II.
In the below image, one of the Hotchkiss machine-guns has been dismounted from the tank, while two more Hotchkiss machine guns remain in their ball mounts in the turret. These were added on the *(star) versions of both the Mark I and Mark II, replacing the turret Vickers machine-guns. A Vickers machine-gun can be seen in the hull of the tank. It is far bulkier than the Hotchkiss due to its water cooling jacket.
The Vickers Mediums equipped the RAC from about 1924 until the mid-1930s. At first, each of the four Battalions in the RAC were to have three CS tanks. However, for some unknown reason, these tanks were not produced. This led to the use of stand-in vehicles during exercises. To mark them as CS tanks, their gun was painted white and the letters ‘CS’ were painted on the turret.
During these exercises with the Experimental Mechanised Force, the Vickers Mediums were to have a profound effect, and seal the fate of the medium tank in the British Army. In 1927, they took part in an exercise against an infantry force. Both the commanding officers agreed that tanks needed speed and mobility as their priority, with firepower a close second. This would allow the tanks to overwhelm the infantry as they moved from a first tank proof location to another, or failing that allowed the tanks to relocate away from any enemy strong point where they had concentrated their anti-tank weapons, and attack where the line was weakest.
Medium tanks, moving at about 12-15mph (about the same speed as the later Churchill tank), were not seen as able to provide enough speed. It is from this exercise that the British thinking about tanks began to move towards the idea of the cruiser tank. In the early 1930s, some twelve tanks were converted to CS standards as the 15-pounder guns were manufactured.
Mk.I and Mk.IA* tanks masquerading as CS tanks during manoeuvres. Photo: Aviarmor
In 1933, a fifth battalion was created in Egypt, from personnel in two armored car companies. These were supplied with the ten Mk.IIA tanks, of which one was converted to CS. It appears two of these Mk.IIA* were still in service in 1940 when the Italians invaded Egypt. Both were reportedly used to help defend Mersa Matruh (not to be confused with the battle of the same name in 1942). From photographs, one appears to have been dug in as a turret bunker, the other appears to have been left exposed. However, there is no indication if this was because it was mobile or there was no time to dig it in.
In the UK, the remaining Vickers Mediums were mostly dragged out onto ranges and used as targets for anti-tank weapon testing. However, a few remained in service during the invasion scare period and were reactivated for use in defense of the UK.
Surviving Mk.II in the Tank Museum, Bovington. Photo: Mark Nash
Vickers in Foreign Service
Australia’s first tanks were a quartet of Medium Mk.II’s ordered in 1927, and arrived in 1929. These tanks were slightly modified as Australia did not use the Hotchkiss machine-gun. Therefore, the ball mounts that would normally be on the turret were replaced with Vickers guns in exactly the same locations. The AA machine gun and the bevel in the turret for this mount were removed. In addition, the Vickers guns had a much larger breech. In order to accommodate this, the bevels on the side of the turret were significantly reduced in size.
Between 1930-1937, these were the only tanks Australia had in the 1st Tank Section. They were used solely as training machines for the Australian Army to gain experience of operating tanks.
One such example exists in the Royal Australian Armoured Corps Tank Museum, Puckapunyal.
Two Australian Mk.II’s. Note the reduced bevel in the turret. Photo: AWM
A 1924 Medium Mk.I, equipped with radio and serving as a command tank during the 1927 manoeuvres at Salisbury plain.
Medium Mk.I with a thicker fake barrel to make it seem like a CS (Close Support) version. The CS tanks were usually tasked with creating smoke clouds to mask the tank and infantry advance from the enemy. This concept was still used during the North African campaign, nearly twenty years after.
Vickers Mk.II CS (Close Support), 1930.
Illustrations by Tank Encyclopedia’s own David Bocquelet
A Vickers Medium fitted with a radio set mounted in two boxes at the rear of the turret. Also note the aerial replacing the rear-top turret machine-gun mount.
Vickers Medium Mark IIA* fitted with asbestos plates on the outside to help with cooling in the scorching sun of the desert. These saw service in Egypt before WWII.
Illustrations by William ‘Rhictor’ Byrd, funded by Golum through our Patreon campaign
In the late 1930’s the British tank forces in Egypt were re-equipped with cruiser tanks. It is possible that some of the surviving Mk.IIA’s were handed over to the Egyptians so they could gain experience in operating tanks. The exact details of what happened in Egypt to the Vickers Mediums is currently unknown, however there were at least eighteen still operational in 1939, four in August 1940, and at least two were dug in at Mersa Matruh until early 1941.
In August 1934, two Mk.I CS tanks were shipped to South Africa. One of these was ‘David’, the original CS tank. In the ten years after its delivery, it had been used for a variety of experiments including having its engine replaced with a new 120hp Armstrong Siddeley engine. This necessitated the rebuilding of its forward hull, and the first gear being disabled. After these trials were complete, the hull was once again returned to Mk.I standards and used as a training hull at Bovington, before being shipped to South Africa.
One tank survives at Bloemfontein barracks, but it is not known if it is ‘David’.
Soviet Union (USSR)
In 1931, the Soviet Union purchased fifteen Mk.II’s. These were called the ‘English Workman’ by the Soviets. Like the Australian versions, they replaced the Hotchkiss machine-guns with larger water cooled weapons, in this case Maxim guns. Thus the turret incorporated the same modifications to its shape. Only one was supplied fitted with a 3-pounder gun. As these were to see service, one presumes they would have been fitted with Soviet weapons. A number were sent to the Karelian Isthmus to be dug in as bunkers. About six of these were quickly overrun by the Finnish forces at the outbreak of the Continuation War, but were deemed useless and not recovered. Most likely because they were scrapped in place.
An ‘English Workman’, fitted with its Maxim guns. Photo: Aviarmor
Variants and Special Cases
In the late 1920’s, several Vickers Medium Mk.II chassis were converted to self-propelled guns to take part in experiments into the future of armored warfare. These were fitted with an open fighting compartment onto which an 18-pounder field gun was fitted with a 360-degree traverse. There appears to have been at least three versions of the Birch Gun, the first with an exposed driver’s position and the second with a semi-enclosed driver’s position. The final version had a completely enclosed driver’s seat and a huge gun shield that almost fully enclosed the rest of the fighting compartment.
Some commentators state that the Birch Gun could double as an Anti-Aircraft gun, however, this is likely due to a misunderstanding. One of the batteries equipped with Birch Guns was given static AA guns to practice with before receiving its Birch Guns. This was likely as a Royal Artillery battery they needed some form of artillery to use for training and routine day to day tasks.
Final version of the Birch Gun. Photo: Public Domain
Mk.II Bridge Carrier
In 1926, there was an attempt to create a bridge carrier. A set of brackets was fitted to the outside of a Vickers Medium tank’s hull on both sides. These contained the components to create a short bridge. Upon arriving at an obstacle the crew would dismount and assemble the bridge before laying it over the obstacle.
Unsurprisingly, this was entirely useless as the crew would be exposed to enemy fire the entire time and so was never proceeded with.
The Mk.II Bridge Carrier. Photo: SOURCE
Tank, Medium, for Radio and Wireless
This conversion occurred in September 1926, and consisted of a large box body replacing the fighting compartment and turret. As the name suggests, it was used as a command tank to house several radios. It was named as ‘Boxcar’ officially, however, due to the dislike aimed at it within the ranks, it was nicknamed ‘Thunderbox’, a reference to an English slang term for a toilet.
Despite this dislike, in 1927 another four were ordered. However, the order was never completed.
The Communications variant of the Vickers Medium. Photo: SOURCE
This was an attempt to create a command tank as a cheaper alternative to Boxcar. Essentially, a Mk.II with a large box applied to the rear to house radios. While, at first glance, it appears to be similar to the Mk.II**, it lacked the other features of a Mk.II** such as the ‘Bishop’s Mitre’ cupola and the Vickers machine-gun. In the latter case, the Hotchkiss ball mount to the right of the main gun was retained.
In 1926, T15, the first Mk.I delivered, was returned to Vickers. There, it was fitted with a set of subframes both front and rear. On these were a pair of wheels with solid rubber tyres. The idea was for the subframes to be lowered and a power take off engaged which would drive the rear set of wheels. Steering was done from a tiller bar inside the cabin.
As well as adding complexity to the design, the added mass would raise the tank’s total weight to over twelve tons. In addition, the wheels had to be placed inside the run of the tracks meaning the axle track was extremely narrow. This, along with the heavy weight, meant a high centre of gravity was balanced on a very narrow axle track. Unsurprisingly, this resulted in significant instability and the project was scrapped after a very short period.
Front view of the wheel-cum-track prototype. Photo: Public Domain.
Medium Artillery Tractor Mk.I and Mk.II
Know as ‘Dragons’, because of a play on words between the words ‘Drag’ and ‘Gun’. The exact date when the first of these was built is in contention. However, the Imperial War Museum’s website says 1922, which is before the Vickers Mediums were delivered. All sources agree that there is a link between the two, but which one came first is unknown and, considering the mystery of the Medium’s creation, it maybe that the Vickers Medium is based upon the Dragon.
Dragon Mk.I towing an artillery piece with full gun team. Photo: Overlord Blog
The Dragon Mk.II. Photo: IWM
Two of these were fitted with Rolls Royce armored car bodies and used in combat in 1941 to help defend RAF Habbaniya.
The two RAF Habbaniya Dragons, named Seal (Left) and Walrus (right). In this picture Seal has had her body changed from the original Rolls Royce armoured car style, and it is thought this is the configuration she saw combat in. Photo: Overlord Blog
This vehicle is HMAT Walrus, although she obviously bore another name at the time this picture was taken. HMAT stands for His Majesties Armoured Tank. At the time No1 RAF Armoured Car squadron used HMAC (His Majesties armoured Car) prefix for all their Rolls Royce armoured cars. Photo: Overlord Blog
Vickers Medium Mk.II specifications
|Dimensions||5.33×2.78×2.82 m (17ft6 x9ft1 x 9ft3)|
|Total weight, battle ready||11.7 long tons|
|Propulsion||Armstrong Siddeley V-8, 90bhp@3500 rpm|
|Speed||15 mph (24 km/h)|
|Range||120 mi (190 km)|
|Armament||QF 3 pdr (47 mm/1.85 in)|
2 x 0.303 Vickers machine guns (7.7 mm)
4 x 0.303 Hotchkiss model 1914 machine guns (7.7 mm)
|Armor||From 4 to 6.25 mm (0.16-0.25 in)|
|Total production||140 Mk.I & 167 Mk.II between 1924-1933|
Links & Resources
Mechanised Force, David Fletcher ISBN 10: 0112904874 / ISBN 13: 9780112904878
Pen & Sword Publishing, Forgotten Tanks and Guns of the 1920s, 1930s, and 1940s, David Lister
Classic Military Vehicle Magazine #188
History forgets. Files are lost and mislaid. But this book seeks to shine a light, offering a collection of cutting edge pieces of historical research detailing some of the most fascinating arms and armament projects from the 1920s to the end of the 1940’s, nearly all of which had previously been lost to history.Included here are records from the UK’s MI10 (the forerunner of GCHQ) which tell the story of the mighty Japanese heavy tanks and their service during the Second World War.