MarineLink is reporting Argentina has recently completed repairs on their only icebreaker, ARA Almirante Irizar.
There are some remarkable parallels between USCGC Polar Sea and Argentina’s Icebreaker, ARA Almirante Irizar. They are essentially the same size (length and beam within a foot and the same draft) and the same age (both commissioned in the late ’70s). The Polar class ships have much greater horsepower with their gas-turbine engines, but their diesel horsepower is very similar. Both have been out of service for years. The Polar Sea since 2010 after failure of five of her six diesel engines. The Almirante Irizar since 2007 after a serious fire.
Sounds like the required repairs were quite extensive. Not surprisingly it cost more that initially expected and repairs included enhancements rather than just a restoration of the previous configuration.
As the Coast Guard looks at the Polar Sea, we will also likely want to incorporate some changes.
Another interesting parallel: The Argentinian breaker is the parent ship for the HEALY.
Looking at the specs, I do see some similarities. Which reinforces my belief that the Polar Sea even without turbines, could still be an effective icebreaker.
I wouldn’t necessarily call Almirante Irizar a “parent ship” for USCGC Healy as they represent completely different generations of icebreakers. The Irizar was designed by the same people who also participated in the design of the Healy. They had more modern hull forms to use as a starting point than something from the late 70s.
If the lines plan for the Polar class was available somewhere, it would be relatively simple and straightforward to make estimates for the icebreaking capability and compare it to other icebreakers. Somehow the published performance (six feet at three knots) seems pretty low considering that those ships are the most powerful non-nuclear icebreakers ever built. Is there something seriously wrong with the hull form and/or propulsion system that wastes some of that power?
Parent ship” doesn’t mean “same ship” or “sister ship”. It means it was the starting point. We don’t need to make estimates of the Polar class capability, its a known thing. If you read the trip reports from the 70’s, you will understand that her actual capability is FAR greater than 6 feet at 3 knots continuously.
Yet, this figure has been on the table when discussing the icebreaking capability of the new polar icebreaker. If what you say is true, there is a danger that the new icebreaker would be less capable than the Polar class in terms of actual icebreaking capability. Also, combine that with the tendency of the USCG to classify icebreakers based on their propulsion power, you could end up in a situation where heavy icebreakers would be replaced by medium ones which have the same “public” performance figures as the old heavies. After all, 3 knots in 6 ft ice is not something that requires 75000 hp unless your hull form is exceptionally bad…
Actually I think the hull form on the Polar Class was one of the things they did right. Really hope they do not repeat the variable pitch props.
I’ve heard someone else say something similar as well.
In any case, a ship with a mission like that cannot be optimized only for icebreaking. Thus, somewhat higher propulsion power demand might be acceptable if that brings considerably better seakeeping characteristics. An extreme ice bow such as that of Kapitan Nikolaev or the river icebreakers would work only on a ship that rarely sails in open water.
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ARA Almirante Irízar returns to ice following ten years of repairs:
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