Lifting Weights Like the Romans

“Other than the castle itself, what is the most impressive thing to see at the Ozark Medieval Fortress?”  I think most people would answer this as the Medieval tread wheel crane of Roman design.  The ancients, like the Egyptians, used water wheels as power and the reverse, meaning harnessing animal power to turn a wheel to lift water.  The  Greeks used cranes made of long logs shaped like a capital “A”.  Pulleys came to the Middle Ages from the ancient mariners, but it was the Romans, amazing engineers that they were, who added the tread wheel, or “squirrel cage”.  Not only did the Romans make extensive use of tread wheel cranes, they used multiple pulleys for added lifting power.  Because of the replacement of the winch with a tread wheel, the maximum load became surprising.  For the Egyptian pyramids a 2 ½ ton stone required 50 men to move it up a ramp.  The Roman and Medieval tread wheel crane was 60 times more capable because one man walking in the wheel gave the same lift!

In the Middle Ages such cranes were used at harbors and in the construction of cathedrals as well as castles.  In fact, even today many cathedrals in Europe still have the Medieval tread wheel crane above the ceiling and below the roof.  So if you visit a cathedral in Europe, look up and above that 100 foot high ceiling may be one of these huge Medieval cranes.

At the Ozark Medieval Fortress at present the crane is used for demonstrations.  As the wall of the castle gets higher, it will be put to work.  At the end of the 2010 season the beams for scaffolding were installed on the East Tower, which puts it at the height to need the crane in 2011. It is expected that the crane will also be necessary to assist in the placement of the “drawbridge” or fixed bridge which will be used to enter the castle.