A motorcycle built in the political prison of Aiud, Romania

Building a motorcycle in prison may seem impossible, but for the brilliant Romanian engineer Sorin Tulea and his two colleagues, it was a reality. Tulea, born on 11th October 1915, attended the Mircea Cantacuzino aviation school and obtained his pilot’s patent in 1936. During World War II, he served on the front lines as part of the 1st Bombardment Flotilla in Brasov, specializing in twin-engine bombing. In the summer of 1941, he was among the first Romanians who responded to the Prut crossing order, even though he had only nine hours of training on the Heinkel 111 bomber at that time. He fought over Odessa, was shot down twice, and was decorated with the ‘Aeronautical Virtue of War’, ‘Golden Cross’ class with two bars, as well as ‘Corona of Romania with Swords’ and ribbon of ‘Military Virtue’.

However, Tulea’s military activity made him a target of the regime installed in 1948, and he was arrested on 24th July of that year without explanation. After being subjected to a sham trial, he was sent to several different prisons, including Jilava, Vacaresti, and eventually Aiud, where he served the majority of his 15-year sentence. While in prison, Tulea’s technical knowledge proved valuable, and he was selected to work in the prison’s factory on 2^nd January 1950. This afforded him better living conditions and the opportunity to use his mind. Over the years, he was responsible for more than 40 projects, including the design of a motorcycle that he worked on with two other engineers during the summer of 1955.

The prison factory closed in 1957, and Tulea was transferred to Gherla, where he remained for only a few months before returning to Aiud. He eventually returned to the factory in April 1960, where he continued to use his skills until he was released in 1963. Tulea’s story is a testament to the resilience of the human spirit, even in the face of great adversity.

Sorin Tulea was freed from prison in July 1963 but was forced to live in the Latesti village, which was inhabited by deportees from the Banat and other ‘enemies of the state’, including the wife of Marshal Antonescu. In November 1963, he was arrested again for ‘treason’ and taken to Malmaison because he was believed to have fled the country while being at Aiud. The matter was cleared up, and he was released in February 1964. After this ordeal, Tulea’s life returned to a semblance of normality.

In addition to his passion for aviation, Sorin Tulea loved motorcycling and photography. He passed away in 2005, leaving behind a legacy of ingenuity and resilience.

Sorin Tulea accepted the challenge of building a motorcycle while in Aiud prison, without hesitation. In an interview conducted by Octavian Silivestru from the Department of Oral History of the RADOR Agency after 1989, Tulea recounted in detail how he and a team of political prisoners built a functional and modern motorcycle from scratch. He believed that the motorcycle could enter series production at any time.

Sorin Tulea: “I must point out that within the Aiud prison, there was a relatively well-equipped factory section where they made all kinds of things needed in trade and for the internal use of the prison. A group of three engineers was working there: Stambuleanu Adrian, the technical director of the I.A.R., who developed the I.A.R. 1000A, the second was Eng. Costel Nicolau, a technical director of Aeronautics during the war, an aviation general, and myself.

One day, the factory manager, then Captain Dorobantu, called us and showed us a letter sent by the Technical Directorate of the Ministry of Interior, requesting that the detainees in Aiud design and build a motor-powered motorcycle. They asked if this was possible to do in the factory. We, along with the prison director, looked at each other for a long time.” Stambulean said, “If we are given everything we need and given enough time, we can do something like that.” Dorobantu said, “We will give you everything you need, make a list, and get to work if you think it can be done.” I asked, “What caused this order to come here, as there are already enough motorcycles with the problems already solved, and now we make a prototype motorcycle? It doesn’t mean anything from a commercial point of view.” He shrugged and said, “These are the provisions, do you want to try this or not?” I said, “We have nothing to lose, let’s see what comes out!” I first asked for machines: a Siemens Plania-type heat treatment furnace, a high-precision WDF-type lathe, a universal Dekel-type milling machine that could mill in all directions, including gears. We also asked for tools, measuring and control equipment, and materials from which we could make such a requirement, because a motorcycle engine contains alloy alloys, aluminum alloys, and other materials that were impossible to find there.

We were told that we would get everything we needed. A group of 30 workers was then formed, the best ones from the factory, who came from Astra Arad, Wolf-Vulcan, Resita and I.A.R. They set up a special room for us, and we got to work. Within a few days, to our great astonishment, a truck entered the factory yard carrying two Wright Cyclone-type aviation engines that were used to equip Liberator aircraft that bombed here. We were told, “Get the materials you need from here.” We started dismantling them and removing everything that could be used as material, not as parts, because the Wright engine would never make a motorcycle cylinder. However, something could be removed from the crankcase or cylinder head. I completely disassembled the two engines using special tools that I made, as they could not be dismantled otherwise. I melted the duralumin from which the engine crankcase was made, and the aluminum from which the cylinders and cylinder head were made, to use as raw materials for constructing aluminum parts. From the point of view of the materials, we requested chromium and nickel alloy steels to make the packaging according to the Romanian standards, or STAS, with the corresponding heat treatments.

I started designing the motorcycle, and the thermal and resistance calculations and general drawing were done by Prof. Stambuleanu. We developed a boxer engine of 125 cubic centimeters each, making a total of 250 cubic centimeters, just like the BMW motorcycles, with four speeds. Gen. Costel Nicolau, who had studied at the Paris Aeronautical High School, calculated the gearbox, including all the gears, and I had to do the overall drawing and execution drawings on all the engine parts in terms of tolerances, roughness, sizing, standards, and heat treatments. The pieces themselves were made, but we realized that the materials made by the Americans could not be used in the working conditions of Aiud. They were centrifugally cast and pressurized or vacuum cast. We took the aluminum for the cylinder heads that we melted and tried to cast the cylinder in that shell, which had been very well designed. However, the casting failed because the aluminum had a casting temperature of around 750-780° C, with a very low fluidity limit. That meant that it needed to be cast in a vacuum or under pressure. Similarly, the cylinders made of aluminum with an inner cast-iron shirt had to be cast under pressure. The aluminum did not fill the shape to make the cooling fins, and we had to devise devices for pressure casting and centrifugal casting. The technicians could not believe that such a thing could have been done at Aiud.

The result was that the engine ran! How did I do centrifugal casting? I took an engine of 800 rpm that put a slide on the shaft. Then, the respective shell was mounted, and the whole engine was put on a support where there was a slide on which a gutter could fit inside the shell. On this gutter, I came with the respective aluminum lion that was immediately removed from the oven, heated on the flames by an oxygen apparatus, and placed inside while the engine was turning.

Aluminum in the fluid state slowly filled the entire shape until it started to come out through various ventilation holes. The centrifugal casting went perfectly in Aiud. When creating the die-cast cylinder, we needed a special device. I used a bench press with a high-pressure screw that could apply up to 200 kgf of pressure. I mounted a piston underneath it that could be inserted into a cylinder near the heat treatment furnace where the aluminum was melting. I connected the furnace to the bench press using a pipe that had a 90° bend leading to the press. Above the piston, I created a side window that could be used to pour in the liquid aluminum, similar to the admixture process used in two-stroke engines. The window was connected to a funnel for pouring. To keep the aluminum at the melting temperature, a team of six people used burners to maintain the temperature of the red pipe.

After being removed from the oven, the aluminum was immediately poured into the funnel located on the left side of the tube. The tube, which extended about 5 meters above the inlet funnel, was used to guide the aluminum into the container below. The aluminum flowed down the tube and filled the container below the inlet funnel. There were six burners that heated the inlet pipe, one that heated the pouring funnel, and another that slowed down the piston movement. Once the entire pipe was filled, the press rotated above while the piston applied a pressure of 200kgf, forcing all the liquid inside the fixed cylinder. When the liquid began to emerge from the ventilation holes, it indicated that the casting process was complete. This is how pressure casting was performed in Aiud!

This story lasted for months. It didn’t take long for the design and construction of the motorcycle, as well as the technological preparation operations for the castings, but the world didn’t want to believe that. The result was that the engine succeeded perfectly, and there was great enthusiasm. All the prisoners and guards began to scream in admiration when molten aluminum began to leap from the chimney, spraying everyone and burning their clothes and eyebrows, but nobody cared about it. We were all glad that the whole operation was successful. Next, we fitted the engine with materials from Wright engines and built a test bench with a tachometer and thermometer to measure exhaust gas temperatures and the temperature in the cylinder head. At full power, the engine reached 8,000 rpm! The engine was constructed in what’s known as a ’square’ design, with the piston stroke equal to the diameter of the cylinder. The cylinder was made of the same material as the Wright engines in a three-core shape. Most American engines at the time used cast iron, especially in the sealing segments, but I melted this material to form a bullion and made segments for the two pistons. I also broke apart the American cylinder heads, removed the lattices made of high thermal resistance iron, melted them down, and made new ones for the motorcycle’s caps. Installing these valve slats in the cylinder head where the valves would operate required hot heating and cold cooling. To expand the cylinder head, we first processed it to the required tolerances, and then heated it in oil to 150°C. After that, we cooled it down rapidly in a chill to -80°C. To cool the cylinder heads to -80°C, we used a carbon dioxide tube. However, this caused some issues, as it made the tight ones impossible to remove and the wider ones difficult to install. It seems that the Americans faced a similar problem and had no other solution. We only used the intake valves from the American engine, which we resized and processed, while retaining the forged valve, as the Americans had done. For precision work, we requested and received a universal Czechoslovak TOS grinding machine and a cylindrical grinding device for the lathe that was part of the WDF lathe. With these machines, I could perform rectification with a precision of one thousandth and surface correction with a roughness of 0.02. We had all the necessary tools, including calibrated screwdrivers and wrenches. The electric and power components followed. We made the carburetors by hand. I used the forged aluminum casing of the American 14-cylinder two-star engine to create the motorcycle engine block. The actual frame was made of CR-MO tubes. The American engines had a beat, and I used tubes from them to construct the front telescopic fork and the oscillating fork, like the MZs later on, as well as the oscillating fork in the rear with gears (not chain), similar to BMW motorcycles. A torsion shaft passed through one of the arms of the fork to carry the movement of the wheel via a conical shaft coupled to a cardan connection that allowed for oscillation. What surprised me was that I had already thought of this solution back in 1954, and when I was released from prison, I discovered that BMW motorcycles had the same technical solution.

The skirt was handmade, long, with bows, and had a rubberized canvas with a casket on the edge that could carry two people. I crafted the exhaust pipe by bending chrome tubes into the desired shape, using sheets of chrome to ensure resistance to corrosion. The tank was bigger than that of a Jawa 250, and I think you could easily cover a distance of 1000 km with a full tank. In total, the motorcycle did not exceed 150 kg. We fabricated the headlamp and the headlamp mirror in-house. While the headlamp, bulb, dynamo, and circuit breaker were obtained from a Jawa, I sourced the tires, inner tubes, and rim without spokes from a Triumph. To complete the build, I crafted the spokes, brakes, and cables on-site. When people looked at the motorcycle, they said it looked like it had come out of a factory. The only thing that seemed out of place was the pedals that the driver had to stand on, which had some rubber sleeves with rice. Since I didn’t have rubber then, I made them from wood, painted them black, and today, you cannot tell if they are made of wood or rubber. All the materials were of ultra-quality, of American origin, and I do not think that they were in a motorcycle factory at that time. When everything was ready, I did a motorcycle ride test inside the penitentiary. The construction began in 1954 and lasted until August 1955. I used the lathe to start the engine and then fashioned a gimbal link between the two. I participated in the two-day testing period, during which we also had to run the sprockets at the gearbox. I constructed a unique contraption to hold the entire gear train, submerging it in a highly abrasive chromium oxide solution. Even with a grinding wheel, we couldn’t achieve the same level of surface roughness on the teeth that our device produced! Despite being held in prison, we managed to produce flawless results that could rival any top factory. We asked to be left alone so we could do what we wanted. After about two days of running through the prison yard, a whole series of commissions led by the security colony began to come. They came, they looked, and they left. They didn’t understand anything at all, but they came because they had to. At one point, along with this commission, some civilians—tall, well-dressed guys with severe looks—began to appear who were clearly not Romanians. They looked at the pictures, but didn’t say a word. They were part of a joint Romanian-Russian commission, so the Russians were interested. In the end, they came with teams of reporters and photographed everything, including the editing, parts, and workshop. After the work was completed, Colonel Clinc, Lugoj’s chief of security, arrived, got on his motorcycle, and left the factory gate. That was the end of it. We created the necessary documentation and waited to see if series production would begin, but we received no information, nothing. However, the fact that the whole Ministry of Interior turned around and did everything I asked for was clearly a matter of a politically superior nature that interested the Russians. The Romanians were not crazy to make such an investment. Years have passed since then, and no one could answer the question that prompted the Russians to do all this and those photo reports. After a long time, while with a friend in Strasbourg, I dug through his library and found a book written by a Russian about Marshal Jukov. There he made it clear that in August 1955, when the Romanians and Russians had become quite nervous that the work was not completed, General Jukov led the first Russian delegation to Geneva. There they met with Eisenhower in an attempt to ‘break’ the Cold War. During these discussions, the Russians had to come up with some documents to show that it was not true that prisoners died in prisons. Thus, they showed political convicts who built motorcycles and high tech. When someone takes photos, it’s to show something, right? In this case, it was to show Eisenhower the conditions in which detainees in Romania lived. The result of the conference was zero, but that was the intention. Professor Stambuleanu was a great socialist leader. When I didn’t know about a president’s visit to London, the question was raised about what kind of socialism the Russians had since socialists like Stambuleanu, Jula, and Hromatca were in prison. The next day, all the socialists were released from prison. Stambuleanu was immediately appointed as a professor of thermal motors at the Polytechnic. He called the Interior Ministry to recover the motorcycle. He asked once, twice; he was a guy who didn’t give up, and to shut him up, they gave him the motorcycle and all the parts. Stambuleanu then exhibited them in the Polytechnic museum. The motorcycle stayed there as long as he was a teacher. When he retired, he took his motorcycle and stored it in his cellar. It remained there after his death until it was taken by the Sighet Memorial Museum.