Current Affairs Man-powered medieval crane at Prague Castle
The exhibition "Charles IV, Emperor by the Grace of God" held at Prague Castle earlier in the year has been described as one of the most important cultural events of the decade. The most valuable art works of Czech origin scattered among collectors in Europe and the United States were successfully assembled for a reconstruction of life under the Luxembourgs. The exhibition has had numerous accompanying events; one of the most interesting is the creation of a perfect replica of a medieval crane which now stands in the Castle's north courtyard. The crane is fully functional and was made according to illustrations from the Wenceslas Bible dating to the late 14th century. This week visitors could see the crane in action and DL went along to admire it. She spoke with Ondrej Protiva, a carpenter who helped to create it and manned it for the benefit of the crowd:
It is all wooden and man-powered obviously - you were just treading the wheel - can you explain how it works?
"Well, it is really simple. You tread like on a treadmill and if you weigh 50 kg then you can move about 500kg. This crane is able to lift one thousand kilograms which is why it has two wheels. Two people can lift a ton without any problem."
What was it used for?
"It was used to build cathedrals and all the Gothic buildings you can see around you. This type of crane was used up until the time of the steam engine. Back then people used man-power or animal-power but of course man-power was more sophisticated because one could communicate with the people working the wheel - so it gave you more control."
How many people worked a crane like this?
"Three or four people were quite sufficient."
How did you get an international team together to construct it?
"Oh, at a symposium in Poland we met a group of people from the United States and they were fascinated to hear that we planned to build it from scratch as they did in the 14th century without any modern mechanisms or tools. Our American friends like that kind of thing and they decided they wanted to help us build it. And by the way this crane is not just a show piece -it is fully functional and we will use it to reconstruct a real castle. Not Prague Castle but Tocnik Castle. We will use it for two years and then it will remain there as an exhibit to show visitors how such castles were built."
"It took about two and a half months - including chopping down wood for it in the forest - we worked with axes not electric saws."
Was just one crane used to build a cathedral or were there more of them? And how long did it take?
"They had more of them, for sure. And building a cathedral took about a hundred years. Sometimes as long as 500 years - it depends on the cathedral."
"No, it wouldn't. The castle is located on a really high hill and there is just a small road leading up there so it is nearly impossible to get a contemporary crane there."
So how on earth will you move this up?
"Very easily. It is like Lego. You can dismantle it and put it back together where you need it. All you need is human power."
When I see you working it you look like a hamster running in a wheel. How does it feel?
"It is actually a very nice feeling. You weigh next to nothing but you can move anything. So it is really ...powerful."
The crane can be seen in the north courtyard of Prague Castle until the end of September.