Vickers Independent A1E1 heavy tank - case report

 Tankers!!

    Today we will talk about a prototype developed in the mid-1920s, shortly after the carnage on the battlefields of the First World War. This unique prototype built by the British was designed to break the stalemate of Trench Warfare, in an attempt to assimilate the harsh lessons learned on European Conflict. This prototype directly influenced several other projects, including those from other countries, which would later fight in WWII. We are talking about the impressive Vickers Independent A1E1 heavy tank.

Vickers Independent Heavy Tank (A1E1)
font: IWM KID 109

History

    The Independent A1E1 is a multi-turreted tank that was designed by the British armaments manufacturer Vickers in the Interwar period. Although it only ever reached the prototype stage and only a single example was built, it influenced many other tank designs.

Corporate logo of  British Engineering Conglomerate
Vickers Limited

    The A1E1 design can be seen as a possible influence on the Soviet T-100, T-35 and T-28 tanks, the German Neubaufahrzeug tanks, and the British Medium Mk III and Cruiser Mk I (triple turret) tank concepts. 

Soviet T-100 heavy tank
Trumpeter 09590 kit box art

Soviet T-35 heavy tank 
Hobby Boss 83841 kit box art 

 Soviet T-28 heavy tank
Hobby Boss 83853 kit box art

 German Neubaufahrzeug tank
Dragon 6968 kit box art

Vickers Medium MkIII tank
World of Tanks art

British Cruiser Mk I CS tank
Bronco 35153 kit box art

Design

    The Vickers Independent was a multi-turret tank design, having a central main gun turret armed with the 3 pounder (47 mm) gun, and four subsidiary turrets each armed with a 0.303 inch Vickers machine gun.

Vickers Independent A1E1 heavy tank
main gun turret - left side view
Notice the pennant with colors of the Royal Tank Regiment
(Royal Tank Corps -1917) 

 

Vickers Independent A1E1 heavy tank
main gun turret - interior view

    The subsidiary turrets were mounted two at the front and two to the rear of the turret (about halfway along the hull). 

Vickers Independent A1E1 heavy tank
front left view, showing 4 of the 5 turrets of the tank.

   As strange as it may seem, the machine gun of the left rear turret was able to elevate to engage aircraft. But due to the visibility and rotation restrictions of this turret, its usefulness was more a matter of boosting morale than practicality.

The AA left rear turret.
At the very least, curious...

I wonder how the gunner could engage a plane with that turret...

    The tank was designed to have heavy firepower, self-defence capability, and superiority to enemy weapons. It had a crew of eight, the Commander communicating with the crew through an intercom system. Like the Vickers Medium MkIII, the Independent also featured a hatch on the sides of the hull, within a rectangular recess, but this was rarely used by the crew, as this cavity was constantly filled with earth and clay. But it's stated in the literature that such side hatches were also designed for the eventuality of removing a seriously injured crew member using a stretcher, which is much more effective and less aggressive than removal vertically, through the other hatches.

Vickers Independent A1E1 heavy tank
left side - Notice the side hatch in his rectangular recess.

    The Independent was never used in combat, but other armies studied it and a few adopted designs derived from it, as we mentioned previously.

Development

    The planning for the A1E1 began in December 1922 when the General Staff of the British Army drew up a specification. This called for a tank with a low silhouette; a rear mounted engine and with at least 2.8 m of trench crossing ability. It was to be armed with a three-pounder gun mounted in the front hull and two machine guns fitted to side sponsons. This was, essentially, an updated version of the World War I Mark V tank.

    Vickers were invited to design a tank to the General Staff specification. However, they also produced an alternative design with a dome shaped turret for a three-pounder gun, surrounded by four smaller turrets, each of which was fitted with a .303 machine gun. Both designs were submitted to the War Office in March 1923.

    In September 1926, the War Office decided to adopt the Vickers multi-tutter design. The tank, with it's five turrets, was considered to be a true "land battleship". The armoured vehicle was to be used for "independent action" and to "work in conjunction with cavalry". The prototype was delivered in October 1926, so construction work on the prototype clearly began well before the order was officially announced. The tank was largely designed by Walter Gordon Wilson.

Major Walter Gordon Wilson,  CMG
(21 April 1874 - 1 July 1957)
font: IWM

    The engine, a 350hp air-cooled Armstrong Siddeley V12, was ordered in August 1926. The drive train used a Swiss Winterthur gearbox. This had oil operated synchromesh which did not need a clutch and drove two compound epicyclic gears inside the track sprocket wheels.

Independent multi-turreted tank
Vickers

    An order for a prototype was formally placed on 15 September 1926 but some work appears to have begun before this date.

Prototype of Vickers Independent heavy tank 
under construction - Vickers plant - 1926
left view

Prototype of Vickers Independent heavy tank 
under construction - Vickers plant - 1926
3/4 front left view

    The prototype was delivered to the War Office in 1926, and the new tank took part in a firepower demonstration for a conference of Prime Ministers of the British Dominions in November 1926. At the time, it was described as Britain's latest and most secret heavy tank.

Vickers Independent A1E1heavy tank in muddy terrain
at the display during the Dominion Imperial Conference - November, 1926
font: Tank Museum - Bovington

Vickers Independent A1E1heavy tank in muddy terrain
at the display during the Dominion Imperial Conference - November, 1926
the reason for the number 10 is unknown
font: Tank Museum - Bovington

 Vickers Independent A1E1heavy tank and a Morris Martel Tankette
at the display during the Dominion Imperial Conference - November, 1926
font: Tank Museum - Bovington

   The steering system was quite advanced, by the standards of the time. The epicyclic gears were hydraulically operated and had a servo assistance system. In large-radius curves, the driver used the steering wheel, while in tight curves, the clutch (operated by levers) and the brake system were used simultaneously. 

Vickers Independent A1E1
Driver station

   The Independent was only 2.7 meters wide, as it needed to be transported by rail, being limited by this gauge. If we look at the relatively narrow width in relation to the length of the tank, we notice that the contact area of the tracks with the ground was relatively long, narrow and therefore unfavorable to changes of direction. 

Vickers Independent A1E1 blueprint
top view

    After extensive tests, which lasted until 1928, flaws and deficiencies were detected, and the engineers focused on the project in search of solutions: the track return rollers, which had rubber tires, were replaced by steel rollers, but later, they returned to rubber ones; the brake linings were changed to use a new material developed by Ferodo. The brakes thus modified were so effective that it was discovered that the stresses they created were causing the suspension to separate from the hull. That same year, as the tank's transmission was behaving very problematically, Major W.G. Wilson was called in to review the tank's mechanical design.

Vickers Independent Heavy Tank (A1E1)
rear right view - version 1926

Vickers Independent Heavy Tank (A1E1)
fornt left view - version 1926
font: IWM KID 42

 

Vickers Independent Heavy Tank (A1E1)
fornt right view- version 1926
font: IWM KID 109

   Following his advice, the transmission was rebuilt with simple, two-speed, epicyclic gears that were mounted inside the sprockets. These gears were connected to the drive sprockets by flexible couplings. Another flaw detected was a certain “flexibility” in the rear part of the vehicle, and this entire area of the chassis was extensively reinforced to strengthen it, and this work ended in 1928. These transmission changes, plus structural hull reinforcements increased the tank's weight to 31.5 tons.

Comparison between the initial version from 1926 and
after the structural reinforcements and upgrade to
the rear transmission, at the end of 1928.
Note mainly the axle connecting the two rear drive sprocket wheels

   The Independent had relatively effective armor, by contemporary standards. The armor on the front of hull and around the crew compartment was 28 mm thick and varied between 13 mm and 8 mm elsewhere. In its original form, the Independent had a mass of 29 tons and could reach an excellent road speed of 33 km/h. Its gas consumption was around 2.5 liters per kilometer, although the engine also burned a whopping 17 liters of oil per hour, a problem that was never effectively resolved during the Independent's lifetime.

    An interesting fact is that the design of this tank was the subject of industrial and political espionage, the plans ending up in the Soviet Union, where they may have influenced the design of the T-28 and T-35 tanks. Norman Baillie-Stewart, a British army lieutenant, was court-martialled in 1933 and served five years in prison for providing the plans of the Independent (among other secrets) to a German contact.

    In the British Army, it remained in use for tests and experiments and even after much work and development, the entire project was finally abandoned in 1935. The Independent was then withdrawn and sent to Bovington Camp, where with its armament and armor, it formed part of the Bovington Camp defenses, in the uncertain times of the Summer of 1940. After WWII it was posted to the Bovington Tank Museum in 1949, where it is preserved to this day.

Vickers Independent A1E1 heavy tank - version 1928.
preserved at Bovington Tank Museum - UK.

Conclusion 

    The A1E1 Independent could be considered, in many ways, a true “white elephant”. Multi-turret tanks proved to be a vehicle that presented poor performance, in tactical terms, as it was impossible for the Commander to direct and coordinate the use of fire from a vehicle with multiple turrets. Compared to the Vickers Medium Mk.III, its contemporary, it had practically similar effective tactical armament, but weighed almost 16 tons more and was much more expensive.

Vickers Medium Tank (A6E2) and
Vickers Independent Tank (A1E1)
font: IWM KID 4490

    The War Office seemed uncertain about its role: was it a prototype of a new heavy tank or just an experimental program of new armored warfare concepts? In both cases, it was a very expensive project and was therefore discontinued.

Specs:

Vickers Independent A1E1
Type	Tank
Place of origin	United Kingdom
Production history
Manufacturer	Vickers (Sheffield) - 1926
No. built	1
Specifications
Mass	31,5 t
Length	7.59 m
Width	2.67 m
Height	2.72 m
Crew	8
Armour	13 - 28 mm
Main armament	QF 3 pounder gun (47 mm)
Secondary.armament	4 × 0.303 Vickers mg
Engine	Armstrong Siddeley  V12 petrol 370 hp (280 kW)
Transmission	4 forward, 1 reverse
Suspension	coil spring bogies
Operational range	153 km
Maximum speed	32 km/h

The kit

    Another 3D printed kit in commission work, manufactured by SS Model kits. The A1E1 British Independent Heavy Tank (#35568). Let's see how this girl behaves...

British Independent A1E1 heavy tank
SS Model kit (#35568) box art

Kojak with the kit, on the bench. The cover art is a little different...

Few parts to build, as most of the details are already printed...
All hatches closed and no decals or metal details.
The instruction manual (a simple A4 sheet) is laconic and terrible, to say the least...
The bald one is discreetly excited...
The kit represents the original version of A1E1 Independent, from 1926.

My kit came with the right ladder fractured, without the parts.
Problems with quality control at SS Models during packaging,
as in the case of the Vickers Medium Mk.III.

But one thing we can talk about is evolution:
the turrets come with their "necks" printed on the hull,
unlike the Medium Mk.III, where we had to guess the true positions.
Positive point for SS Models!!

But now, a disappointment: the damn delaminations and
resin without complete curing!!! This is terrible!!!
Internal view of suspensions - right side

And in the left side too... Disgusting!!!

Another improvement compared to the Vickers Medium Mk.III kit:
reference points for gluing the suspensions!!!
Wonder!!!

The problem is that the fittings are too tight...
some are even too tight...

My solution: I used slightly larger diameter drills,
widening the holes, to allow for a less traumatic fit.

I enlarged all the holes (red arrows),
except those for the main wheels (yellow arrows)...

And, after some work, the suspensions were glue
 into their respective places. Important tip: use superglue gel ,
as it takes longer to work, allowing you to adjust so many fittings...
Left side

Suspension - right side.
During the gluing and adjustment of the suspensions,
some parts of the track links fractured (very fragile...).
I replaced them with a super-thin Plastruct rectangular profile (red arrows).

The main turret fits inside the neck on the hull.
It's a very tight fit...to facilitate rotation, I abraded the material
with a rotary sanding tool from my Dremel

And the secondary turrets are the opposite: the fitting is internal
in to the turrets. Same wear with the same tool...

Abrasion wear on the turrets and hull neck...

And the turrets with smooth and precise fittings...

Detail of the repair on the sides of the right track links.
Sculpture with scalpel on plastic...
No big deal!!!

Let's now repair the fractured ladder on the right.
I'm going to use Plastruct plastic angles for this...

Stairs like new!! I took advantage and made the missing straps
on the right fender of the tank, with thin copper wire.
The repaired tracks complete the set...

   The 47mm cannon provided by the kit seems too thin and short to me... So, I had a great idea: why not replace it with the cannon that came in duplicate in the Vickers Medium Mk.III kit? They are the same guns, of the same caliber, on the original vehicles. 

   Let's get to work: the first thing is to check the blueprints and photos of the vehicle and, indeed, the cannon provided is a little short. Ideally, it should protrude a little in front of the hull. See the blueprint below:

The relative position of the 47mm gun with the front of the hull.

Two 47mm guns: one weak...the other strong!!!
The barrel cut to the same size as the Vickers Medium Mk.III

And the "new" gun installed in the turret.
Tommy was happy with the change!!!

Much better!!

Scratch details (copper wires) on the left side...

Vickers Medium Mk.III and A1E1 Independent heavy tank
Two true flapper girls, from the Roaring 20s!!!

    And now, let's measure the Independent: The measurements are in centimeters, as in the technical specifications of the real vehicle in the literature. Once again, scale work cannot be considered bad...

The length of the kit in relation to the Independent is almost perfect...

...as well as the width.
Congratulations, SS Model !!!

    And speaking of congratulations, I think that SS Models is evolving, having seen the evolution of the track link profile between the A1E1 Independent and the Vicker medium Mk.III. These two vehicles have very similar links in real life. But in the scale models, notice that the pattern of the Independent's links is correct (retentions in low relief), while in the Medium Mk.III, an older kit, the pattern is completely inverted, in high relief.

The right and the wrong!!

    But continuing, let's make a locking system for the turret, so that it can rotate without falling out of the hull. The theory is to apply a 1mm thick plastic disc to the bottom of the turret, so that it can receive a screw that goes through the hull from below, forming an axis that allows the turret to rotate 360°. We will also increase the thickness of the plastic in the screw region, so that it has a greater amount of material to hold on to. Here's the theory:

The famous Panzerserra turret locking system

    First of all, use a sharp-edged compass to cut a plasticard disc (1 mm thick) to be glued to the bottom of the turret. See pics below:

The plasticard disc is cut, ready to be glued to the bottom of the turret.

A 2mm thick plastic block will be glued to the center of the disc,
where the screw will lock...
This is all so that the connection between screw
and plastic is well reinforced and strong...

Reinforcement glued to the plastic disc...

    Then, I glued the disc to the bottom of the turret and, carefully and taking correct measurements, drilled the bottom of the hull, so that a long screw could be screwed into the disc at the bottom of the turret, through the hole in the hull. Sorry, but my photos failed at this stage, but the schematic drawing perfectly reproduces what was done...

The famous Panzerserra turret locking system
in position

Turret in positions, with free rotation...
Unfortunately, the secondary turrets had to be glued...

    Because of the irregularity in the bottom of the tank's hull, it was impossible to make an access panel to cover the screw head. My solution was to cover the crosshead of the Phillips screw with a thin sheet of plasticard, directly on the metal.

Another plasticard disc...This time, much thinner (0.3 mm).

    I noticed that two movement limiters on the rear secondary turrets were broken on my hull. It was just a matter of making these pieces with two pieces of stretched plastic... Stephen Tegner's photo was precious at that moment...

Thanks a lot, Stephen!!!

    The kit also does not feature the two rear running boards (the front ones, yes...). I made these pieces with PE scraps from my scrap box...

The two rear running boards installed...
Notice the pattern of the links of the tracks, 
what we talked about earlier...
As you can see, the kit represents the original version, from 1926.

And the girl is ready for painting!!!
Notice the two front running boards...Right front view

Right front view...

The A1E1 Independent with a coat of white primer.
A quality of the SS Model kits is the almost absence of printing lines,
which greatly improves the final appearance of the scale model.

White primer- right view

    As I said previously, the version represented by the SS Model kit is the standard version of the Independent, before the structural reinforcements at the rear and the transmission change (in addition to details on the exhaust system on the tank's rear deck). Therefore, it is this model that will be represented by this kit. And nothing is more boring than a kit without any markings. But researching the 1926 version, I noticed that during the Independent's display to the Prime Ministers of the British Dominions in November 1926, the tank displayed the marking 10 on the side of the turret (perhaps a propaganda move: 10 vehicles in production??!!). Another detail is the 47mm main gun, the recovery cylinder and the mantlet painted in silver color. See the pics below:

Vickers Independent A1E1heavy tank in muddy terrain
at the display during the Dominion Imperial Conference - November, 1926
font: Tank Museum - Bovington

 

Detail of the main gun, mantlet and recovery cilinder
in silver color.

   The dark green color were based on the colors used by vehicles at the time. The profile guide represents what I hope to achieve:

Panzerserra markings and colors guide profile

    The huge problem is that my printer is a laser and does not print white. Cutting a white film to this size is an almost impossible task... My solution was to print the numerals on a transparent film, in a light color (yellow) with the edges outlined in black. The objective is to apply the decal and serve as a guide for a freehand painting, made with a fine brush and white acrylic paint. The following requirements will be necessary: the patience of a monk and the steady hands of a surgeon.... Let's see what happens. But first, let's look at the base color, with some tonal variations:

The girl, dressed in dark green, as fashion dictated at the time.
Our flapper girl is very vain!!!
left front view

Right front view

The looong tail of the Independent...

She really has an aggressive look...

    After a thin layer of Future, to prevent the damn silvering, we applied the decal printed on transparent film. The absence of contrast in white leaves the colors completely "fainted". Let's paint white over number 10...

Decal in position. The dynamic duo Micro-set and
Micro-sol is still acting...
Left side of the turret

Decal in position. Right side of the turret

Now, patience and a steady hand to fill in the yellow with white...
first layer - left view

The right side after first layer of white painting...

        The girl was definitely nicer with the historical markings...

Vickers Independent A1E1 heavy tank
left view

Vickers Independent A1E1 heavy tank
front left view

Vickers Independent A1E1 heavy tank
front right view

Vickers Independent A1E1 heavy tank
rear right view

Vickers Independent A1E1 heavy tank
rear left view

Almost forgetting: we will paint the cannon, the
recovery cylinder and the mantlet in silver color.
Masking done with adhesive tape and toilet paper.

And our girl's nose is painted in silver!!!

Close view - right side

Close view - left side

Starting the weathering....

Discreet weathering...
this vehicle was very well taken care of...

Rear view

    I think I'll add a detail to this tail: a roll-bag doesn't kill anyone!!! Value Gear Details to the rescue!!!

Choosing a suitable roll-bag...

...and after painting...

...and installed on the lady's rear deck!!!

    And after a few more finishing touches, our flapper girl was ready: with you, Vickers Independent A1E1 (standard version) heavy tank, as she performed at the maneuvers during the Dominion Imperial Conference , in England, in November, 1926.

Vickers Independent A1E1 (standard version) heavy tank
Maneuvers during the Dominion Imperial Conference 
England - November, 1926.

Vickers Independent A1E1 (standard version) heavy tank
front right view

Vickers Independent A1E1 (standard version) heavy tank
front right top view

Vickers Independent A1E1 (standard version) heavy tank
left top view

Vickers Independent A1E1 (standard version) heavy tank
front left view

Vickers Independent A1E1 (standard version) heavy tank
front right view

Vickers Independent A1E1 (standard version) heavy tank
 right view

Vickers Independent A1E1 (standard version) heavy tank
rear right view

Vickers Independent A1E1 (standard version) heavy tank
rear left view

Vickers Independent A1E1 (standard version) heavy tank
 left view

Vickers Independent A1E1 (standard version) heavy tank
with Kojak

 

Vickers Independent A1E1 (standard version) heavy tank
and Vickers Medium Mk.III tank.
Two british multi-turreted interwar tanks

Vickers Independent A1E1 (standard version) heavy tank
Maneuvers during the Dominion Imperial Conference 
England - November, 1926.

See you soon, Ladies and Gentlemen, 

in my new project!!!