What happens when water freezes? Well most people know that it expands and it is this expansion that causes water within rock cracks to break apart rocks.

But what would happen if it couldn’t expand? Scientists in the 18th century first started looking at this question and no amount of metal or coverings would work. The ice would form and cavalry shells would explode with the pressure.

There is an ice phase diagram ( copied below ) which shows the different forms of ice and this suggests that some 43,000 pounds of force per square inch would be needed to keep the water from expanding. But what then happens to what when it becomes ice which can’t expand? Well it becomes Ice II and in total there are 15 different types of ice which can form as the pressure and temperature increase.

The different forms have different properties as well.

water phase