It may not be the largest or most powerful ice breaker ever to set sail (that record is held by Russia's nuclear-powered NS Yamal), but America's Polar Star is easily one of the most badass. This 75,000 horsepower ship can crush a two storey ice wall in a single swipe of its mighty bow.
Ice floes in both the arctic and antarctic oceans are constantly jostling and shifting like ice cubes in a tumbler of whiskey. Normally, ships can simply push individual bergs out the way when navigating these polar sea routes. However, as was the case with a Russian research vessel, the Akademik Shokalskiy, last month, these routes can and do freeze solid, trapping ships for weeks or even months at a time.
When that happens, stranded crews can request assistance from specially built icebreakers like the US Coast Guard's Polar Star Heavy Icebreaker. Built by Lockheed in 1976 and stationed in Seattle alongside its sister, the Polar Sea, the Polar Star is one of the most powerful non-nuclear ships in existence.
The Polar Star — which just received a three-year, $US90 million overhaul — measures nearly 122m long and displaces 12,000 tonnes of water. Six 3000 HP diesel engines supplement a trio of Pratt & Whitney 25,000 HP gas turbines to provide the ship with sufficient ramming speed to decimate almost any ice wall. At a sustained pace of three knots, the Polar Star can shred through a solid 1.8m of ice pack. With a running start, the ship can pound through walls of ice up to 7m tall, no problem.
The ship's ice-breaking abilities come not just from its massive power-plant but also its specially-designed hull. Clad in nearly 5cm of steel shell plating and supported by an internal steel beam structure, the Polar Star essentially pushes its bow onto ice floes and then relies on the ship's weight to crush it.
Spending six to eight months rolling around the polar ice caps is enough to make even the hardiest Coast Guarder long for shore leave. To compensate for the arduous work, the Polar Star is outfitted nearly as well as modern submarines. The ship's 15 officers and 126 enlisted enjoy access to four lounges, a library, a gym, a general store, even a US Post Office among other amenities. And since everything outside the ship is either white or more white, the ship's interior forgoes the typically drab grey of US naval vessels for more colourful paint schemes.
And when the Polar Star isn't saving stranded ships, it performs a number of secondary duties, including transporting science teams, surveying the year's ice formation, SAR operations and resupplying the National Science Foundation's antarctic science stations.
The Polar Star was actually on its way to deliver supplies to the NSF in Antarctica when it was pressed into service last week, charged with saving the Akademik Shokalskiy vessel, as well as the Xue Long ice breaker that had previously tried and failed to save it. The Polar Star is expected to reach the ships by January 12 and should have them extracted from their icy tombs shortly thereafter. [Stars and Stripes - Wiki - USCG]
Update: Figures. Just when the Polar Star gets on the scene, both the Xue Long and Akademik Shokalskiy manage to navigate themselves free through a narrow crack in the ice sheet. Still, all's well that ends well.