Ice Architecture
 ... and when a group of Canadian engineers go on winter vacation!
Yes we all know, Canada is a half frozen land, but the cold weather doesn't stop us from going out and having fun, even in the WINTER! It all started when I and a couple of other friends spent a weekend in winter at a friend's family cottage up north. Back then we were all undergraduate engineering students at the University of Waterloo. The tradition is to break the frozen lake's ice at night and do the Polar Bear Dip, welcome to Canada! After the dip when we were warming up around the wood stove, someone said lets do something with the chunks of broken ice. Twenty minutes later, we had an Ice Arch designed on a napkin!

Here is what happened the next morning, it was -23°C:

From left to right: Isaac, Bruno, me and Dan.
Blocks are being held in place under their own load. For the foundation, I cut a shallow right angle triangular groove on the lake.

The very next year, we decided to build something more challenging: an Ice Igloo! I designed the igloo; however my plan sounded so far fetch to my friends that one of them made a bet that he would sleep in the igloo for a night if we could build it!
First round of blocks are in place and Arshad is already trying it out!
Here is the trick: first round of the blocks should have a slope from the ground level to the actual height of the blocks.This helps to lean the blocks on each other to transfer the load!
As the spiral rounds of block goes up, a shallow cut on the top helps to lean the wall inward and get the dome shape.
You can see the spiral shape of the blocks here. Leaning on the wall so it doesn't collapse inwards till we put the last rounds of blocks in place.
And here is the finished Ice Igloo! and now Arshad has a great story to tell his grandchildren about spending a night in an Ice Igloo!