The enormous boulder on which the statue of Peter the Great (also known as the Bronze Horseman ) sits is known as the thunder stone. According to local legend it was given it’s name because it was believed thunder had split the piece off from a larger rock.
The stone, which was estimated to have weighed 1,500 tonnes, was discovered in marshland by a local, S.G. Vishnyakov, at Lakhta near the Gulf of Finland in 1768. The story of how the stone found it’s way to St Petersburg is just as epic a story as the statue itself.
Having found the perfect base for the memorial to Peter the Great, the big dilemma for sculptor Falconet was how to move such an enormous boulder all the way to Saint Petersburg. He wanted to work on cutting the rock right where it lay but Catherine the Great was having none of that, she ordered it moved.
The first problem was how to lift the damn monstrosity which was buried half way down in the marsh and the second was how to transport it to the sea where it was to be placed on a specially made barge .
Enter Marinos Carburis, a Greek engineer who happened to be a lieutenant-colonel in the Russian Army at the time. Having dug the thunder stone out of it’s muddy home he then placed it on a metallic sledge which slid over bronze spheres which were about 13.5cm (6″) in diameter (a little like ball bearings).
The rock was then hauled , using only human labor, 6km (4 miles) to the Gulf of Finland. The process would end up taking 400 men 9 months to finally get it to the sea. One of the problems was they could only lay a 100m of track at a time. It was estimated the men managed to push, pull and heave the thing 150m a day.
During it’s journey stonecutters were busily shaping it into a wave. Catherine would also periodically visit to check on the progress. On it’s arrival an enormous barge was constructed and two warships were on hand to support it from either side.
The Thunder Stone is believed to be the largest stone ever moved by man.