During cold Russian winters the River Neva through Saint Petersburg becomes covered with ice, with icebreakers required to keep the waterway open. On my visit to Saint Petersburg I saw them at work.
The icebreaker headed upriver through a clear channel.
Until it encountered the first ice floe.
The icebreaker lined up towards the ice.
Then charged into it.
Crashing over the top.
And breaking up the slab.
Which then flowed downstream towards the Gulf of Finland.
The icebreaker I watched was named ‘Минск’ (‘Minsk’) but there is at least one sister vessel – icebreaker ‘Одесса’ (‘Odessa’).
While downstream I saw the much larger oceangoing icebreaker ‘Красин’ (Krasin) – now a museum ship.