system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do Icebreakers work?

With the new recently about a ship being stuck in the ice, and three "Icebreaker" ships being sent to rescue it, one is now also stuck.

How do Icebreaker ships work, and what are their limitations?
gpt
Their hull, especially the bow (front) is made much thicker and heavier than normal and their engine/s are more powerful than you would expect on a craft of that size.

In very thin ice (1m ish) they bash through it. 

As the ice gets thicker the bow rides up it and the weight of the ship crushes down and cracks it.

Different ice breakers have their own limit. Unfortunately, the ship stranded in the arctic is in ice just beyond the capabilities of the ice breakers sent to help.