Back in my childhood I used to spend a lot of time at my grandparent's cottage. It was a wooden house amid a small orchard, just under the top of a hill outside of Ljubljana. My parents would often drive me there in a red Zastava 101 on weekends and holidays. I played with surplus plumbing parts and old tools that were lying around, slept in the attic and had nightmares from having to go to the outhouse after dark.
The cottage was designed and built by my grandfather as a weekend retreat. He was a mechanical engineer who moved to Ljubljana with my grandmother to one of the first apartment complexes in the city, proudly displaying his professional title above the door bell. He was designing turbines for hydroelectric power plants at the heavy machinery manufacturer Litostroj.
When I wasn't wasting potable water or setting things on fire, one of my favorite ways of spending time there was browsing through a book Elektrotehnika v slikah. I could always find it stashed between two planks above my grandfather's bed. It was bound into a hard crimson cover with gold lettering and even back then already had the smell of an old paperback. The title translates to English as Electrical engineering in pictures and it's actually a Slovenian translation of the German original Elektrotechnik in Bildern by Gustav Büscher.
I don't know how that book got there. I doubt that my grandfather learned anything new from it, considering it was printed in 1968 and he finished his 4-book, 5-inch thick thesis on designing Francis turbines 6 years earlier.
In any case, I loved to turn its pages. I looked at the pictures and read the short paragraphs until I knew most of it by heart. First few chapters at least, where the book explains the basics like current, voltage and resistance with simple water analogies. There, almost each paragraph had an illustration that was just serious enough not to appear overly childish and funny enough to keep it interesting. The book was, after all, targeted at adults.
Later chapters went on to describe electric machinery and vacuum tubes with more elaborate mechanical analogies. Judging by the tear-and-wear of the pages, I skipped most of those parts back then. Equations were definitely beyond me at that point, and I'm not sure I even bothered my parents asking about them.
In the chapter about hydroelectricity, the Završnica power plant is featured on several occasions. Maybe it was there in the original version of the book. Or, more likely, the illustrations were adapted when the book was translated. Regardless, Završnica was the first public power plant in the region, so it definitely deserved the attention. By the time this book was published, it was already more than 50 years old.
For a long time, if someone would ask me, that plant would be the only one I could name. I didn't know where it was, but the name has definitely stuck in my head.
Even a month ago I wouldn't know where to put it exactly on the map. I was therefore a bit surprised when I found out that the plant is now being converted into a museum and that I will see it on my visit of HE Moste.
I now know that the dam on river Završnica is a short hike from the town of Žirovnica and is surrounded by a pleasant recreational park. I learned that the pressure pipeline goes under the town and discharges into river Sava below. And I also learned that the prominent building on the top of the hill you see when driving on the Gorenjska highway is its surge tank. Even though machinery in the old turbine hall is being cut open for display, the surge tank above still serves its original purpose. From up close it is an impressive monument to early 20th century hydro engineering.
A walk through the museum revealed many sights that were familiar to me from the book, like the mechanical frequency meter above. I don't think I ever saw a real one before.
What I also learned on the tour is that HE Moste next door was my grandfather's first big design project at Litostroj.
The original bronze Francis turbines dimensioned by him and cast by Litostroj have long been replaced, damaged by cavitation and sand particles carried from the mountains by river Sava. However one of them is now proudly displayed on a plinth in the park in front of the plant.
After HE Moste, my grandfather went on to design power plants throughout the former Yugoslavia and abroad. His design bureau was involved in projects all over the world. He kept a globe in his office marked with flight paths of his intercontinental flights that circled the Earth.
The visit to HE Moste and HE Završnica last month has been as much a technical interest for me as it was a way to remember my grandfather. Without doubt he helped spark my interest for engineering. Either by letting me browse his books or watch him spend his days drawing carefully calculated lines on translucent paper.
He died in 2011 and was designing turbines in his home office for as long as he could hold a pen against a drafting table. His cottage is gone as well and Elektrotehnika v slikah is now standing on a bookshelf in my living room. It was nice to see in person one of more than a hundred power plants he helped design during his career that are still producing electricity.