BERLIN, Germany — It’s pretty rare to see a sight so beautiful it makes you laugh out loud with all the excitement of a child.

The best shot is from the prow of the Oder.

That’s how beautiful the Oder-Spree waterway in Berlin looked early this morning as a huge pink sun rose over a glittering expanse of ice.

We were on board an ice-breaker, one in a fleet of five tug-like boats tasked with carving a route through the city’s frozen rivers so that water-freight, namely coal, can make its way through.

The coal barge we were guiding was 140 meters long. When they’re fully loaded they can cut through the ice but they can’t turn without the help of an ice-breaker like the Oder.

And with Russia umming and aahing about whether to keep delivering gas through Ukraine to Europe, those coal deliveries are crucial right now.

Each week, 40,000 tonnes of coal come into Berlin along this waterway.

We were at the port at 5:30 a.m. waiting to board the boat. It was pitch black, seven degrees Celsius below freezing and she wasn’t there yet.

All you could hear was the sound of millions of tonnes of ice creaking across the river — incredibly eerie, like a hideous chorus of screams on low volume as though people are trapped below.

It's cold but the view is spectacular.

It’s not something you can communicate well in a television report, you need to listen longer than TV gives you time for.

You could hear our boat, the Oder, long before you saw her lights from the din the ice made as she crashed her way through.

You’d have thought those charged with ice-breaking would be pretty cautious about how slippery it is. But the crew of the Oder seemed to take a fairly cavalier approach.

No sooner had they moored than one took a not inconsiderable leap from the boat to shore, only to slip on take off and really barely make it.

Minutes later, our hearts in our mouths (it would have been a very cold and very dark rescue operation), our camera-bag took a nose-dive for the depths as we were clambering on board and was saved just in time by a hook low down on the side of the boat. A lucky escape from a potentially very expensive accident.

We were blessed with a beautiful morning as we led the coal barges along freshly carved routes through the ice. 

The three-man crew of the Oder and ice-breakers like her operate long shifts in freezing temperatures to keep coal coming into Berlin.

Sometimes it can take as little as one hour for the river to freeze over completely again.

One small link in the complex infrastructure which keeps a city warm when it’s way below zero and there are dangerous political machinations at work on the international energy front.

Watch Frederik Pleitgen’s report of ice-breakers keeping energy supply lanes open.