USCGC Polar Sea
We send our only Heavy Icebreaker almost 20,000 miles, to the end of the earth with no back-up.
Take a look at this news release regarding an upcoming award ceremony where the Commandant will recognize Petty Officer 1st Class Kevin Oakes, Petty Officer 3rd Class Augustin Foguet, and Seaman Manon Mullen.
They had to repair a thrust bearing bracket. This is a really strong fitting designed to absorb the push of 25,000 HP and it broke.
EM1 Oakes fixed a generator, apparently a main propulsion generator, that had developed a short that resulted in loss of with a surfboard repair kit.
They had ” three fires and one major lube oil leak, which can quickly ignite into fire.”
We are blessed with excellent enlisted people, who do extraordinary things, but we cannot keep doing this. It is only a matter of time until one of our two icebreakers suffers a catastrophic failure far from any assistance.
We are still close to ten years from a new heavy icebreaker, but while it will hopefully give us a more reliable replacement for the Polar Star, it will not fix the problem.
We have a acknowledged need for medium icebreakers. The Congress seems to recognize our lack of icebreakers as a problem, and there are relatively near term alternatives available in the shape of an icebreaker now excess to Shell’s requirements and another begun and well advanced in construction, which is now stopped.
Wouldn’t it be better to send two ships south?
Chuck Hill's CG Blog 
That scenario is not limited to Ice Breakers. The original Deepwater Plan was to facilitate all the old warhorses retirement by 2020. With the RAND post 9/11 study suggesting it be 2015 or 2010. Coast Guard leadership allowed that to stretch to 2030 and not use the contract performance guaranty to hold the defense contractors feet to the fire. Look at the Haitian and Deepwater platform missions as well as Cutter Readiness Data over the past 5 years. The borrowed time has come and gone.
Here’s an article with photographs from the USCGC Polar Sea:
http://maritime-executive.com/features/in-photos-the-fate-of-the-polar-sea
That technology might have been top-of-the-line in the 1970s, but it’s not something the United States should rely on in the 2010s in some of the most remote areas in the world:
“We manually tune these potentiometers in port to put all the diesel-electric main engines on the same horsepower curve. And then we sail to Antarctica and hit the first piece of ice, everything here is vibrating, and the engines won’t play well together anymore. This is what Polar Star is sailing with today. It’s terrible – but it’s a system we know, and replacing it would be difficult and risky.”
They are making a case for not bringing back the Polar Sea. Restoring the Polar Sea would be a fool’s mission, They were not even reliable when they were new.
Problem is the Polar Star still has the same unsupportable systems.
We need three heavy icebreakers, but we are not going to get a new one for ten years. There is definitely going to be a gap between the service life of the Polar Star and the new Polar Icebreaker.
We need to bite the bullet and accept that the only alternative is a massive renovation of the Polar Sea. Maybe it cost $300M but if it lasts ten years it will be worth doing.
Did the PIB ever go through FRAM?
@Lyle, neither of the Polar Class have ever been FRAM’d that I am aware of.
You think we should FRAM both them to give us some breathing room? Granted they are 20 years past FRAM stage. And that is expecting the current PIB replacement program to continue.
We need three heavy icebreakers. the first new one will not be fully operational until 2028, assuming the other two are built at two year intervals the third new PIB will not be operational until 2032.
I think we should do a major renovation on Polar Sea including a full repowering with diesel electric propulsion using fixed pitch screws to make it truly reliable with the intention that it should last until at least 2032, Given it is going to take at least two years to renovate it that is only 14 years. I think we can do that for $300M or less. That will give us some breathing space then we can look at Polar Star and decide if we want to do the same major renovation or just continue to hobble along using the present configuration.
If w first renovate the Sea and then also the Star we can stretch out the building program a little further, but we don’t have to decide on the Star until we see how it goes with the Sea.
Can the PIB make do with two shafts? Rebuild the engine rooms and put the NSC’s 2 diesel engines in, and two of the NSC’s Gas Turbines, or even two of the LSC’s turbines in place of the NSC’s if they will fit? Will that be enough power? Common parts will ease maintenance cost.
Since it has not gone through FRAM, and if they can rebuild it like we rebuild BB-48 and add 20+ ytears to it i say go for it. Plus we could use the PIB’s as test bed for the technology that will be used in the future PIB’s My maine concern is that 2028 is wishful thinking for brand new ships.
Sorry for Ramblin 1:15AM here.
The diesel-electric conversion of the USCGC Polar Sea is probably possible in theory, but I’m not entirely sure about the feasibility of such project. The Polar class was built with a rather unique propulsion system for a heavy icebreaker – the only ice-going ship that I know of that had a gas turbine mechanical/diesel-electric propulsion system was the Finnish 1A Super ice class ferry Finnjet, built in the 1970s and scrapped a few years ago, which was limited to 29.4 MW (out of 66.4 MW) in ice-covered seas.
The first issue I can think of in “full repowering with diesel-electric propulsion” is how to fit the electric motors inside the hull. The current DC motors are rated at 6,000 hp each and I would expect ~20,000 hp AC motors to be significantly larger and heavier. Can you fit them in the hull without changing the alignment of the shafts, assuming you go for direct drive and not reduction gears? Do you have sufficient space for switchboards, propulsion transformers and drives? Where will you put all the new diesel generators and their auxiliary systems? These questions can be challenging even when you’re designing a new vessel, let alone a conversion with a large number of constrains.
Lyle, you could probably achieve some kind of icebreaking capability with two shafts, but considering that the Polar class has triple shaft/single rudder layout, reducing that two twin shaft would mean the rudder would not be in the propeller slipstream anymore. That would mean that the maneuverability, particularly in heavy ice, would be extremely poor. You’re looking at 10+ km turning circle.
I also recommend you to forget gas turbines, at least mechanically coupled ones. The propulsion system in the Polar class has caused problems since the beginning, so step one would be to get rid of the problematic parts and go for something simple, such as fixed pitch propellers driven by AC/AC power plant. That’s what everyone else has done in the 1980s. However, using the gas turbines to produce electricity could work, but I’m not familiar with such systems.
Chuck, as far as I know, it’s not possible to run the gas turbines and electric motor in parallel on the same shaft. Also, I recall reading somewhere that the maximum continuous rating of the gas turbines is just 60,000 hp, and that 75,000 hp can be sustained only for a limited amount of time.
Tupps, I was not suggesting mechanically linking the gas turbines, but they could also be used as generators. It is being done on the Royal Navy Type 45 destroyers. https://en.wikipedia.org/wiki/HMS_Daring_(D32)
and on HMS Queen Elizabeth.
Chuck, ok. The same system is also in use on RMS Queen Mary 2 and the Chilean “icebreaker” Contraalmirante Oscar Viel Toro (ex-CCGS Norman McLeod Rogers). However, being such a rare configuration in icebreaking vessels, I don’t know how it works when you take the dynamic loading of the power plant into account. How fast can it ramp up?
It’s certain that a gas turbine generator has a better power-to-weight and power-to-footprint ratio than a diesel generator, but if you’re talking about a long-endurance vessel such as an icebreaker, how does it compare when you also need to consider the additional fuel required by the more thirsty gas turbine?
By the way, when calculating the propulsion power, remember that the overall efficiency of a modern AC/AC diesel-electric propulsion system is about 0.9, so for every 100 kW on the diesel engine you get 90 kW on the shaft. Also, don’t forget the other consumers and the “hotel” side.
I wonder how those engines on the NSC can handle cold intake air. If they can’t, the heating is a significant energy consumer.
I would also think diesel electric would be best, but gas turbine generatiors are an option.
Presumably diesels would be used most of the time and the gas-turbines brought on line only for the more demanding ice conditions.
The Type 45 desroyers have been having some problems in high temperature operating conditions, but I have not heard of gas turbines having trouble in the cold. They are after all like aircraft jet engines that regularly operate in the cold of high altitude, including over the pole flights, And they have worked well enough on the Polar class.
Gas turbines require a lot of volume to handle the quantity of intake and exhaust gases. The Polar class design obviously accommodated this but using them as generators rather than mechanically connecting them to the shafts means they could be mounted much higher in the ship, shortening the trunks and freeing up a lot of volume. In HMS Queen Elizabeth the main propulsion gas turbine generators are located in the superstructure.
The USN DDG-1000 class are also gas turbine electric.
Chuck, the current Polar class configuration has mechanically coupled gas turbines driving controllable pitch propellers, a configuration that has caused a lot of problems over the years. This can be seen for example in the Marine Executive article I linked earlier – in “diagram 1”, “R/G” stands for reduction gearbox. If my memory serves me right, the air intakes are just forward of the aft smoke stack in that construction that looks a bit like a second bridge.
However, many modern icebreakers – such as the USCGC Healy – have their diesel generators installed on the main deck level. This has a number of advantages for power plant design and also moves the center of gravity upwards, making the ship more comfortable in heavy seas. There’s no reason why the same couldn’t be applied for gas turbine generators if they were used. The downside is that they take up a lot of “useful” deck space and you’ll have less vertical space for the exhaust system.
Yes I am afraid the Polar Star is almost certain to have a major failure before its planned end of service.
The Polar Class currently are configured with 75,000 HP provided by three gas turbines and 18,000 HP from six diesels. I don’t believe the diesels and turbines are operated in combination so lets say to provide comparable power you need about 75,000 HP.
Replacing the entire plant with six diesel generators using the same engines currently used in the Berthof Class would provide just under 60,000 HP, not quite equal, but close.
We might be able to use components from the Lewis and Clark Class T-AKEs.
http://www.naval-technology.com/projects/lewisandclarke/ It uses four diesel generators and two motors to produce 35.7MW or very close to 50,000 HP, to drive a single shaft. Bumping this up by adding two more genertors and another motor would allow very close to 75,000 HP on three shafts.
It might be a bit more complex, since it has not been done before, but if we could convert the type of engines used in the Bertolf class to generators, two LM-2500 gas turbines and two of the diesels could provide over 75,000 HP. Assuming we are using electric propulsion, which allows us to used fixed pitch screws, the engines don’t have to be tied to particular shafts. Any one engine or combination of engines could power three shafts.