Thickness of Ice

My Swedish greatgreatgrandfather was a colorful person. One of his «hobbies» was to be the first one to walk on the ice on the nearby lake in the autumn and the last one to do the same in the spring! On one occassion the old man fell into the icecold water. This was of course extremely dangerous, and could easily have taken his life. «So what happened?» asked the relatives when he returned home. «Well», he said, «first I called for help, but when nobody came, I had to get out of there myself!»

In December 2006 a famous Norwegian skier who had won medals in the Olympic Games, was not as lucky as my relative, and while skiing on a frozen lake a little north of Oslo, fell through the ice and drowned.

Following this tragedy, the newspapers told the public how thick the ice has to be to carry persons and vehicles, reminding everybody that even when you measure a certain thickness, the ice may be thinner in some places.

5 cm thick ice can carry one grownup weighing 75 kg
10 cm thick ice can carry a motorcycle weighing 600 kg
15 cm thick ice can carry one light private car weighing 1200 kg
20 cm thick ice can carry one heavy private car weighing 2700 kg
25 cm thick ice can carry one medium heavy lorry weighing 3600 kg