A hidden 'Leonardo da Vinci' is revealed in Alfred Krupa's breathtaking inventions

Behold an unsung visionary of modern engineering.
Deena Theresa
Alfred Joseph Krupa with his wheeled suitcase (left), and folding canvas catamaran (right).Alfred Krupa

On February 18, 2020, Interesting Engineering wrote about Alfred Krupa, a Yugoslavian artist who supposedly invented the wheeled suitcase in 1954, years before a patent for the same — "Rolling Luggage" — was granted in 1972 to Bernard Sadow, owner of U.S.Luggage, now part of Briggs & Riley Travelware.

Alfred Joseph Krupa died in 1989, with his idea of the wheeled suitcase unrecognized.

But in May 2022, Krupa's grandson, Alfred Freddy Krupa, wrote to us, unlocking a gigantic treasure trove of inventions. Alfred Krupa's "semi-preserved" folder revealed sketches and plans for several inventions, ranging from small-scale practical gadgets to "grandiose" ideas.

They included the wheeled suitcase, a system to prevent the sinking of large ships, a glass-bottom boat, an unsinkable rescue "boat-chamber with legs", a shipwreck rescue balloon, an underwater scooter with a camera, shipwreck rescue equipment, equipment for the protection of persons at sea from sharks, and so much more.

According to Freddy Krupa, his grandfather developed the ideas a few years after World War II in the postwar socialist nation of Yugoslavia, when the Space Age was still several years in the future, and "technical gadgets visible in the James Bond movies were decades away".

Was Alfred Joseph Krupa the hidden "Leonardo Da Vinci" of the 20th century?

Alfred Joseph Krupa's "semi-preserved" folder revealed sketches for several inventions. Source: Alfred Freddy Krupa

Alfred Joseph Krupa: an inspired inventor overcomes a difficult childhood

Alfred Joseph Krupa was born in Mikolow, Poland, into a mixed German-Polish family with Jewish roots, according to Alfred Freddy Krupa, a painter and professor, who shares the same name and profession as his grandfather. 

"He had an extremely difficult childhood during the war and post-war years of World War I, leaving him without his parents. His grandmother Therese raised him, and his brothers, Gerhard and Engelbert. Sister Hildegard Marie seemed to have been adopted at one point," Freddy Krupa told IE in an email interview.

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Since their grandmother Therese's pension wasn't enough to live on, the boys lived multiple lives — for example, carrying suitcases for people from the train station, and stealing coal from surface coal mines on the property of landowners. "Grandpa drew portraits for money… everything," said Krupa to IE.

After completing high school, Krupa traveled to Krakow, Poland, where he studied painting at the Academy of Fine Arts. He then graduated in 1937, just before the onset of World War II.

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In 1943, Krupa escaped occupied Poland to Yugoslavia, where he was one of the core artists of the Art of Croatian Antifascist Movement and a member of the resistance movement. But he couldn't save his sister, Hildegard Marie, who perished in the Auschwitz-Birkenau concentration camp in 1944. (Freddy Krupa mentions that his grandfather and sister, Hildegard Marie, were registered victims of Nazi persecution.)

Following the war, Krupa began exhibiting his paintings, which included portraits and landscapes in watercolor, oil, charcoal, chalk, and pencil. "His was the first exhibition of an academic artist after the end of the Second World War in Zagreb," said Krupa. "It took place at the Ulrich Gallery in 1945, the oldest exhibition hall in Zagreb." In 1946, Krupa started teaching art at the Karlovac High School, where he remained until his retirement, in 1971.

Among other things, he was a pre-war amateur boxing champion in Poland, and a shooter. After leading a very eventful life, Alfred Joseph Krupa sadly died of a heart attack in Domobranska, on October 16, 1989.

Interesting Engineering: Did your grandfather discuss any of his visionary ideas with you or someone in the family?

Alfred Freddy Krupa: Of course. He certainly talked to my father the most [Alfred Krupa's son Mladen worked on one of his father's inventions —  which prevents large ships from sinking]. But, in the late 1980s, before his death, my grandfather and I would stay up at night to talk about everything, including his inventions. He was very proud of his work but somehow disappointed that he failed to realize everything he set out to do. He had planned to continue working on his inventions, but his sudden death prevented him from doing so. [His inventions were] extremely fascinating to me but I was also kind of angry because he was not more aggressive in finding ways to realize his ideas. Today, I think he was just tired of fighting.

IE: Alfred Joseph Krupa's sketches seem to suggest he focused mainly on new ideas about rescuing people. Was he influenced by the war?

AFK: I don't know how that came about. But your conclusion is common sense and logical. I thought about it a lot and realized that his life in Poland until the end of World War II was often reduced to the question "how to survive", "how to cope with a crisis". He had seen so many deaths, and been in so many dramatic situations, that it certainly changed his perception of the significance of life.

Today it is pretty logical to add small wheels to a suitcase, but many generations traveled without them. I am strongly convinced that my grandfather created such a practical invention due to the hardships of his childhood. As you know, he was forced to start work early, along with his brothers. He had mentioned that the workload was heavy. I assume his practical and insightful mind wished the suitcases were wheeled.

Regarding, the life-saving devices at sea, I assume he began thinking of those in 1945 when he got his first job on the Island of Krk. I can imagine that he noted the issues faced at sea.

The majority of Alfred Joseph Krupa's sketches contain ideas for underwater and rescue equipment. Source: Alfred Freddy Krupa

IE: Among the sketches, did any materialize into tangible products?

AFK: There are photographs (that are now well known) of some of his inventions. Regarding the suitcase with wheels, we can see that he devised both the variants which were later patented by Sadow and Plath. My dad says that my grandfather made four to five pieces and that the family used them for a long time. One survived until my time in the mid-1970s. My grandfather never owned a single purchased wheeled suitcase, only [those of] his own [design].

He had made a simple device for resting on the train, because at that time trains in Yugoslavia were very uncomfortable — they were made of boiled wood, on which it was very difficult to sit comfortably. His device resembled a load-bearing pendulum that you hang on the space for suitcases above your head — then you could lean on a plate that was fixed to rubber bands. The photo exists. He also made diving masks in the late 1940s, as he couldn’t buy them at the time. Of course, he could not realize his great ideas due to the lack of help from the system.

The only preserved item is some 70-year-old old version of a portable periscope box made of impregnated canvas for underwater viewing. Others have been lost over the turbulent decades.

IE: Had any of his peers seen his folder? Would you know what they thought of his inventions?

AFK: I know that in the 1950s and 1960s he communicated with many, including various Yugoslav and Croatian institutions. There was also an attempt at the British Embassy. He had exhibited [the first glass-bottom boat] in Belgrade at the Fair of Technology and Innovation in 1957. There were various reactions and negotiations, but nothing ever resulted in concrete cooperation. In one case, the Yugoslav Register of Ships, in their letter dated March 13, 1956, informed him: "Consistent with the International Convention for the Safety of Life at Sea from 1948, which was accepted by our state / Yugoslavia inflating cannot be accepted as correct." So, it looked like his marine life-saving invention, which involved the inflation technique, was (internationally) doomed from the start.

As for his opus of invention, I think that people have seen some isolated proposals, but so far [they've] never been presented to the public in their entirety. There are also some letters he exchanged at the time. I have a document from the Uprava za patente Federativne Narodne Republike Jugoslavije [Patent Office of the Federal People's Republic of Yugoslavia] dated December 2, 1960, in response to the patent registration of his version of the boxing gloves on May 3, 1956. Among other things, they said that the use of horse hair exclusively for boxing gloves was prescribed and therefore could not accept his solution. He was again stopped by formal conventions, as in the case of his solutions to save ships from sinking and people from drowning.

I think this well illustrates the environment and the situation in which he operated.

Tangible inventions
With his body support system for trains and skis for walking on water. Source: Alfred Freddy Krupa

IE: How does it feel to have such a massive treasure chest of work by a genius?

AFK: To me, it has always been something of a personal, intimate treasure. Something very difficult to put a price tag on. My whole family is very proud and I'm glad that the time has finally come when the world would valorize the inventive genius that my grandfather, mentor, and friend was.

IE: What do you hope to do with these sketches?

AFK: I would like to make it public to the full possible extent, to preserve them from being lost or destroyed (sold to a museum?) Perhaps we could think of developing these ideas.


Alfred Freddy Krupa added that he continues to research his grandfather's legacy. Documents and letters were provided to substantiate his story.

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