Saturday 18 May 2019

In Search of the Perfect Sphere

The idea of building spherical tanks was born long ago. Spherical tanks were treated as a viable weapon during WWI, but interest in this topic peaked in the 1930s and 40s. Most of the time, work reached the prototype stage, or sometimes only scale demonstration models were built. Nevertheless, spherical machines continued to enchant the minds of engineers. In our time, the "descendants" of spherical tanks are rather common, having lost their drawbacks.

A derivative of the bicycle

Let us take a small trip back in history to understand where spherical machines came from before we dive into discussion of combat vehicles. Strangely enough, the bicycle was the ancestor of the spherical tank. Bicycles that existed in 1817 were radically different from the ones we see today. They had neither pedals nor a seat, in the classical sense, and the bicycle was made from wood. Like it often happens with new technologies, there was no one singular vision of what a bicycle was supposed to look like. The first designs that resemble modern bicycles appeared by 1840.

The first bicycle with the modern layout is not that old. It appeared in 1884, two years after the first automobile. Bicycles of all sorts continued to compete with it in the late 19th century, and the concept of a bicycle with a rear chain-driven wheel that was the same size as the front wheel did not take off immediately.

The Hemmings Monowheel, the first monowheel design.

Bicycles with two different sized wheels were common. A number of them had a large rear wheel that was driven. Others had a large front wheel that also housed the pedals. This layout has not died out, and is still commonly used on children's tricycles.

The penny farthing was the peak of differentiation between the front and rear wheels. These strange devices were the first to be called "bicycles". The penny farthing had a huge front wheel and a miniature rear wheel. The design seems strange and looks uncomfortable, but based on the author's experience, one can quickly get used to it. This type of bicycle had a higher top speed than its contemporaries.

A drawback of this "two coin" scheme (the name "penny farthing" was based on the small farthing and large penny coins) was that the cyclist could easily go over the handlebars in case of sudden braking. Considering that the "penny" was over 1.5 meters tall, this would not end well. One solution was to place the rider inside the "penny" and get rid of the "farthing" entirely. 

Otto Safety Bicycle, the first commercially successful device of its kind.

It's hard to tell who was the first to propose what is currently called a monocycle or monowheel. Four such devices were put on the marker in 1869, and all four were very distinct. It is likely that the father of the monowheel was Richard Hemmings from New Haven, Connecticut. According to the book "The velocipede: it’s history, varieties, and practice", published in April of 1869, Hemmings invented his device in 1867. The vehicle was powered with the hands, which was a drawback, and was built out of wood. Nevertheless, Hemmings' monowheel had all the characteristics of this kind of vehicle. One advanced feature was the protection from mud that was flying off the wheel.

Another ancestor of the spherical tank, the dicycle, appeared in 1869. It was invented by another American, William Mackaraghan from Pittsburgh, Pennsylvania. His design was much more stable than the monowheel.

The dicycle was the first commercially successful ancestor of the spherical tank. This was made possible by efforts of Eduard Carl (Charles) Friedrich Otto. He developed a very good dicycle in 1879. A year later, it was put into production by the Birmingham Small Arms company (BSA), a future giant in the bicycle and motorcycle market. BSA built 953 Otto dicycles over four years. Each one cost 13 pounds Sterling. The inventor founded the Otto Safety Bicycle Company, which dealt in the sales of dicycles.

Otto continued to perfect his creation, but the popularity of dicycles began to decline. In 1883, BSA put a tricycle into production, which was much more stable and easy to drive. Otto quickly realized that his product had no future and switched to traditional bicycle production.

The Edison-Puton monowheel on display at the technical museum in Sinsheim.

Rapid development of technology at the turn of the century affected these vehicles as well. However, none of the dozens of patents contained any kind of revolutionary breakthrough or radical change.

An inventor by the name of Garvagalia presented a monowheel equipped with an internal combustion engine at an automobile dealership in Milan in 1904. This was the start of the era of equipping dicycles and monowheels with engines. This variant became especially popular. For instance, in 1910 Eric Edison-Puton built a monowheel powered by a 3.5 hp De Dion engine. The vehicle drove well, but had its quirks. Like other monowheels, Edison-Puton's creation had issues with driving at low speeds. The driver also had to have a very high degree of skill. The vehicle had more drawbacks than benefits. It was a bold experiment, but an experiment nonetheless.

Alfred D'Harling's "Aero-unicycle".

Monowheels and dicycles remained popular, despite an absence of commercial success. This was largely due to their unusual looks. The amount of inventors who strived to create a successful design did not decrease. For instance, Alfred D'Harling from Saint-Louis built an monowheel driven by a propeller. This was one of the first vehicles to be featured in Popular Mechanics. The unusual vehicle had a very high top speed, up to 107 kph.

Professor Christie and his vehicle.

Another vehicle that drew close to a spherical tank was built in 1914. Designed by Elsa Christie from Marion, Iowa, the vehicle resembled a monowheel with two auxiliary wheels along the sides. The vehicle had some semblance of a hull, and the extra wheels helped with stability. Christie created his vehicle for racing. Equipped with a Liberty engine, it could reach a speed of 400 kph, but work did not progress past an experimental prototype built in 1923.

By this point, work on this sort of vehicle had progressed far. Military designs also appeared.

Ramming spheres

The first device that could be considered a spherical tank was built in Germany. This vehicle was actually built, not just patented. The Hansa-Lloyd company received an order for a fighting vehicle i 1916. It was ready by February 1917. The vehicle, named Treffaswagen, was a three-wheeled design, but very distinct from Lebedenko's tank. The wheels, 3.3 meters in diameter, took up most of the volume of this 18 ton vehicle. The wheels did not only propel the tank. They also contained machinegun mounts for firing at the flanks. The engine was located in the rear, where a tail wheel also helped in turning the vehicle.

The front of the hull had a gun mount and a driver's seat. The main armament of the Treffaswagen was the 20 mm Tankabwehrkanone Becker M11 anti-tank gun. A later version was supposed to use the more powerful 57 mm Cockerill-Nordenfelt M1888 cannon, which was captured from the Belgians. This gun was also used as armament for the A7V tank.

Treffaswagen on trials. This vehicle is the only spherical tank armed with weapons that reached the trials stage.

Trials of the Treffaswagen took place between February 1916 and March 1917. The tank with a four man crew had to compete with the heavier A7V. Hansa-Lloyd's vehicle lost the fight. The tank was disassembled in October of 1917. It remains the only spherical tank-like vehicle that was not only built, but seriously considered for service. The Treffaswagen was the only such vehicle to receive armament. It was also the first cylindrical tank built. One advantage of this type of vehicle was higher stability in both axes, and ease of driving.

Hugo Gernsback's trench destroyer. 

While Hansa-Lloyd was working on its contraption, spherical tanks began picking up popularity on the other side of the Atlantic. It was driven by Hugo Gernsback, a proponent of technological progress. His magazine, The Electrical Experimenter, proposed all sorts of technologies, including military ones. Gernsback is known as a science fiction author (the Hugo award was named after him), but he was also a talented engineer and the creator of dozens of inventions. He was the first to realize the combat potential of monowheels. Gernsback's first publication on this topic is dated 1915. 

The gyroelectric destroyer and its controls.

Two of Gernsback's projects in this area are quite interesting. One, called "trench destroyer", was a dicycle with a cabin in the middle. It contained the engine, fighting compartment, and driving compartment. This "ferris wheel" could protect trenches from enemy infantry. A year later, in February of 1918, a second design was published. The "gyroelectric destroyer", as Gernsback called it, was a monowheel. The cabin, engine, and driver's compartment were located inside the singular wheel. The armament was moved out to sponsons. The "gyroelectric destroyer" was very close to a spherical tank.

Arsene Pare's "Engine of Warfare" was the first full fledged spherical tank. It was never built, but the principles of his design became common.

The first proper spherical tank was patented by Arsene Pare from Brockton, Massachusetts. The patent application for his "Engine of Warfare" was submitted on May 1st, 1917. Before Pare, all such vehicles were multipurpose. Pare's invention, however, was designed for war from the start. The vehicle even resembled a large grenade. It consisted of a spherical casing that contained another sphere inside of it. Movement was achieved through wheels that rolled along the surface of the outer shell and made it rotate in the needed direction. Internal components were placed as low as possible so that the center of mass was low to the ground. The "Engine of Warfare" was also amphibious, like many other spherical tanks.

Pare's design was a weapon in and of itself. The vehicle could be used to ram buildings or other targets. Hatches for throwing out explosives were also present.

Frank Lautebur's combat vehicle that could also double as a peaceful tractor.

Another weaponized design was a "tractor" proposed by another American, Frank Lautebur, in February of 1918. Lautebur's "tractor" was something in between cylindrical tanks and dicycle spherical tanks. Nearly the entire surface of the vehicle was taken up by wheels. Grousers were installed to increase traction. Since there were two wheels, the vehicle could turn like a tank, which meant that Lautebur's "tractor" didn't have the most common drawback of spherical tanks: difficult control. A "tail" with a wheel was attached in between the wheels to improve stability. If necessary, two vehicles could be connected together side by side.

The USA was home to most spherical tank projects, but other countries produced some as well. A number of patents were issued in Italy. The most interesting one was the "Monocycle vehicle" patented by Karlo Pomilio from Rome. It was a monowheel with a hull that partially extended outwards. This was an unusual tank, but a tank nevertheless. There was no peaceful variant. Gun mounts were to be installed in the front and rear, as well as the sides. In theory, Pomilio's design was supposed to have good mobility, but nobody ever built it. It was far too unusual. The end of WWI also seriously cut the budget for military designs.

Albert Mobare's spherical tank, 1926. 

Interest in spherical fighting vehicles waned in the 1920s. One of the few devices of this type was the "Machine du guerre" patented by Albert Mobare in June of 1926. A platform for the driver, engine, and other components was held in an ellipsoid hull. The "Machine du guerre" had no weapons and could only crush its enemies. The project was never built.

Maximum ricochet

A burst of interest towards monowheels and similar vehicles revived the spherical tank. Creations of English inventor John Archibald Purves triggered this revival. A Ph.D. at the age of 30, the inventor was chiefly involved with optical devices. In the early 30s, he radically changed his direction and began working on a monowheel that could compete with the automobile.

The most refined of the Dynaspheres. This one is equipped with an automobile steering wheel.

Purves filed his patent in September of 1930, but his creations really became popular in 1932. The Dynasphere, as the creator called it, consisted of a large wheel composed of metallic rings. A frame inside the wheel housed the engine and other components. An awning protected the driver from dirt flying off the wheel.

Purves proposed a classic monowheel. The size was anything but classic. The first Dynasphere was over two meters in diameter. The electric motor could accelerate it to 48 kph.

The second type, the most well known, had a number of changes. To reduce the weight, Purves made the wheel from metal and leather. The three meter tall vehicle weighed 450 kg. A 2-cylinder engine from a Douglas motorcycle propelled the second Dynasphere.

The third model, named Dynasphere 5, was even larger. The number in the title indicated that the vehicle could fit 5 people. While the first two vehicles were steered by tilting, the Dynasphere 5 had a traditional steering wheel. An 8 person vehicle was also planned, but never built.

An illustration from an article about a single wheeled tank. Later it will often turn up in documents.

The Dynasphere was not a commercial success, but it led to the revival of monowheels in the public eye. The early 1930s saw the return of the arms race, if only at the experimental level. Popular Science published an article in November of 1933 on a "one wheeled military tank, steered by one man". It described an invention by Angel Garcia Gutierrez from Terrytown, New York. There was nothing unusual about the design at first. The same large wheel with a frame that houses an engine, fuel tank, seat, steering wheel, and other components. However, Gutierrez's monowheel was armoured and armed. The vehicle was covered in armour from both sides. Entrance hatches and observation ports were located on the sides of the vehicle. Each half also had a machinegun in a ball mount. Gutierrez decided to make his vehicle amphibious. The hull was supposed to be buoyant. Extra stability was added through small wheels on each side.

Gutierrez's patent. This was essentially an armed monowheel with an armoured hull.

Gutierrez never built his vehicle in metal, but this publication was noticed outside of the USA. The Red Army received information about alleged production of this vehicle. These news kicked off development of similar work in the USSR. Authors of some vehicles that pitched their inventions during WWII pointed to Gutierrez's work as an example that was followed.

Illustrations of the "Tumbleweed Tank", which became the classic image of a spherical tank.

Popular Science also gave the world another vehicle that became the classic spherical tank. The June 1936 issue has a brief article titled "Novel War Tank Resembles a Rolling Ball":
ROLLING over the ground like a giant ball, a high-speed “tumbleweed tank” proposed by a Texas inventor is a new addition to modern war machines. A spherical hollow steel driving cab is inclosed by a rotating outer shell consisting of two cup-shaped halves fitted with circular traction cleats. Motor-driven gears, mounted on the inner sphere, rotate the outer shells to roll the tank along the ground. Steering is effected by varying the speed of either of the rotating traction shells. Machine guns are fired from the stationary cab through central firing slots and armored turrets at the sides. The heavy driving motor, centrally placed on the cab floor, gives the tank stability and prevents it from rolling sidewise. The inner shell can be sealed against poison gas, while the power plant is completely inclosed to minimize the danger from exhaust fumes. The inventor states that the tank’s spherical shape presents the smallest possible target for enemy bombs or shells, and all but direct hits would glance off its curved sides. 
The blurb was accompanied by a painting of a spherical tank bristling with machinegun barrels. The same vehicle was displayed on the front cover, where the tank was even more powerful. While the driver was handling a machinegun in the article illustration, the tank on the cover had a cannon. 

These images had an impression on the magazine's readers, which included military specialists and engineers. Soviet specialists assumed that the tank on the cover was built and tested. 

Richardson's "battle ball" in reality.

In reality, the illustration was just a variant of the "Autoball and Armoured Ball" invented by Andrew Richardson from Texas. Richardson filed his patent in June of 1932. It was approved in March of 1936, and that is when it came to the attention of Popular Science.

As you can see, there were two projects. The first was a spherical automobile, a much more original design than the Dynosphere. The basis of the vehicle was an aerodynamic hull with doors. It contained a cabin for four passengers, engine, controls, and other components. A bar passed through the center of the hull, which was attached to the outer hull. Unlike the inner hull, the outer hull was not entirely closed. It consisted of several "wheels" with rubber rims. Turning was performed by shifting the inner hull of the Autoball to one direction. The design was fully complete and could have been built, but this was never done.

A spherical automobile was proposed along with the tank.

The second project that made such a noise in the press was much more conceptual. The Armored Ball was radically different from the Autoball. The only thing they had in common was their shape. The Autoball was a monowheel, while the Armored Ball was a dicycle. Andrew Richardson was the first to use this layout for an armoured vehicle. Like Gutierrez, Richardson's design was amphibious. THe overall shape of the patented vehicle was the same as shown in Popular Science. Hemispherical wheels were attached to a central power source. They were equipped with cleats to increase traction, which doubled as paddles in water. Due to the dicycle layout, the Armored Ball could turn in place. The patent does not show any armament, but the description suggests that it should be present.

A spherical tank from 1941. Like with Richardson's device, it was never built.

Richardson's Armored Ball was never built, although it did revive the topic of spherical tanks. One of the advantages of this layout was the increased odds of ricochet when shells struck the hull. However, there were far more drawbacks. Even though the vehicle would not be long, a one-man spherical tank would have a diameter of 2-3 meters. The diameter would have to be even larger if the vehicle had a larger armament and a proper crew.

The installation of armament introduced a number of problems. The gun would have a limited traverse. A rotating turret could not be used. These issues became an insurmountable obstacle for spherical tanks. This type of tank was never built in the USA, even though over ten patents were filed.

Kugelpanzer in Patriot Park.

The Germans built at least one experimental spherical tank. Patriot Park has a vehicle on display known as the Kugelpanzer (a detailed walkaround can be found here). The name was given to it arbitrarily. No one knows who designed and built it. The theory that it was built by Krupp has no evidence to support it. According to the most common theory, it is an observer's vehicle, but there is scarcely enough space inside for an engine and the driver. This is most likely simply an experiment to demonstrate the possibility of building a vehicle in this form factor. According to the documentation, the Kugelpanzer arrived from the Kummersdorf proving grounds.

There are no components left inside, but it is known how it was supposed to work The vehicle was driven by a two cylinder air cooled motorcycle motor. Its power was enough to propel the 2.5 ton vehicle at a speed of 10 kph. A gear train turned the wheels. The rear wheel, controlled by control rods running under the hull, helped with turning. The engine and other components, including the driver's seat, were installed on a platform in the lower part of the vehicle.

One can only guess at the equipment that was installed originally. One thing can be said for certain: work did not progress past the experimental stage. Some people with overactive imaginations draw weapons onto the Kugelpanzer, but this design was unlikely to progress past the prototype stage. The design had one significant drawback. The small wheel would act as an anchor on soft terrain.

Grand Panjandrum, the only spherical tank-like device that was publicly tested during WWII.

Another country that decided to build something similar to a spherical tank was Great Britain. The War Ministry received many proposals for spherical tanks, and a very odd one was built. Initially, the idea seemed sound. The Great Panjadrum, designed by Neville Shute of the Directorate of Miscellaneous Weapons Development (DMWD), consisted of two wooden wheels 3 meters in diameter with a cylindrical hull between them, filled with explosives. The vehicle was propelled via rockets attached to the wheels. The target for the Grand Panjandrum was German fortifications on the Atlantic Wall.

The trials were carried out in public, with photos taken and videos filmed, to ensure that the Germans would find out about it. However, the trials did not go well. The rockets flew off the wheels, after which the Grand Panjandrum became uncontrollable. Even though the design did not move past trials, the Grand Panjandrum made its mark on history.

Elie Aghnides' patent for a spherical combat vehicle.

Elie Aghnides was the luckiest of all spherical tank inventors. Born in Istanbul, the engineer realized his talent in the United States. The Aghnides aerator is still used in faucets today. His success in the creation of filters was also considerable.

The start of WWII motivated him to take up military designs. His first patent was filed in May of 1942. Aghnides proposed an armoured dicycle. Hemispheres on each side had ribs to improve traction, which worked as paddles in water (the tank was also amphibious). One significant difference from Richardson's tank was the presence of small wheels in the front and rear that would not allow the hull to rotate in motion. The driver sat in the front and operated the machinegun that was installed in a ball mount.

A development of Aghnides' spherical tank. The wheels would later migrate to the Rhino in a slightly altered form.

A model of Aghnides' vehicle appeared in pages of popular science magazines, but it was never built. His work was not done in vain. The inventor developed his design further. The Rhino, a joint project with Marmon-Herrington, was the result. The brutal looking machine had impressive off-road performance. Its hemispherical wheels were inherited from the sphere tank. The Rhino remained an experiment, but remains a pretty good example of a successful sphere tank drive.

Frank Maclearty's tank.

American sphere tanks remained on paper. It is not surprising that some creators tried to sell their works abroad. One of these was a design by Frank Maclearty. This vehicle was similar to the Lebedenko tank visually, but built very differently. The vehicle had two massive wheels, each of which was essentially a classical monowheel. Each wheel had its own engine, located as low as possible. The engine and suspension were attached to sprung frame. Another feature that made Maclearty's tank similar to sphere tanks was the installation of gun sponsons on the exterior side of each wheel. The inventor filed his patent in February of 1942, and offered the design to a Soviet delegation in January of 1944. The GBTU reviewed the project and declined. The Department of Inventions had enough similar proposals.

Before its time?

The history of sphere tanks looks like a constant string of failures. It is not surprising, as many technical solutions first come to a dead end. Successful designs do not come immediately. One of the more interesting modern incarnations is the GroundBot, created by the Swedish Rotundus company in 2008. The spherical vehicle with cameras on each side is reminiscent of the spherical tanks. The GroundBot's hull is equipped with grousers, which lets it travel on snow and sand, as well as climb hills. In addition, the device can swim. However, no one is talking about sending it into battle just yet. The GroundBot and analogous GuardBot are built for patrols and observation. However, interest towards this design seems to have died.

GroundBot, the best known modern sphere tank.

There is another descendant of the spherical tanks that is very much thriving. It's called the Segway. Indeed, it is built according to the same principle. Thanks to a system of gyroscopes, the Segway is stable, solving one of the drawbacks of the spherical tanks. The Segway is used by some police forces, so in a way the spherical tank is being used for its original purpose. Either way, it's too soon to put an end to the history of spherical fighting vehicles.


  1. Right away this made me think of Mr. Garrison from South Park Colo. who built a slightly updated copy of the wheel to revolutionize travel.

  2. I remember many of these from the pages of the awesome but sadly defunct "Tales Of Future Past" site, nice to see a bit more technical detail about them.

    Also read a description of the Great Panjandrum final test in a book about oddball wartime Brit inventions once (many were rather more successful, such as the assorted rocketry and "plastic armour"). Topkek stuff - stuffy senior officer types diving for cover to evade loose propulsion rockets and someone's dog chasing one of the things across the beach.

  3. I think we all agree that the WW 1 English rhomboid track designs made the concept of wheel tanks irrelevant. Tracked vehicles just have superior traction and a lower profile to any similar wheeled vehicle. But it's fun to see the imaginative concepts.

  4. 400km/h in the 1920's? This sounds really hard to believe. Planes where struggling to reach these speeds around that time.

  5. Trouble is, these are all BIG and easy to see. And if you can see it, you can kill it.