USCG Ice breakers


#1

report to congress


#2

Oh…the horror…

Another witness at the hearing—Mead Treadwell, the lieutenant governor of Alaska—stated:
[Regarding] The issue of the ships, the company that is building these ships for Shell
[Oil] has visited with me and other state officials, and that’s why you heard us say in our
testimony that we think the leasing option should be considered. We don’t have a way to
judge the relative cost. But if on the face of it, it seems like it may be a way to get us the
capability that the admiral needs.72


#3

[QUOTE=z-drive;177703]Oh…the horror…[/QUOTE]

yup…lots and lots of verbiage in that report all about the USCG leasing an icebreaker.

me shmells the odor of a setup although some may recall my earlier opining that Shell should buy the vessel from ECO then donate it to the USCG to refit for their needs. Everybody wins in this case. The USCG gets a nearly new icebreaker for nada, Shell gets great publicity and press plus a nice tax deduction and don Vito Chouest gets his bloody money!


#4

I didn’t get that impression from the report. Too small and leasing offers no savings and actually costs more over the ships life. Short term, yes.


#5

Some info about the future USCG polar icebreaker:

https://www.fbo.gov/utils/view?id=6bf790d9a55643d036407a559ee67352 (PDF)


#6

I wouldn’t call AIVIQ either a heavy or medium icebreaker. It’s just an unproven MPV with some icebreaking ability.

It might make sense for the USCG to buy AIVIQ at a modest price of perhaps $25 to $50 million with a budget of no more than $10 million and one year for conversion. It could play a stopgap Alaska icebreaking and rescue towing role at reasonable cost while we wait for a real icebreaker to be built and funded.


#7

[QUOTE=tugsailor;177731]I wouldn’t call AIVIQ either a heavy or medium icebreaker. It’s just an unproven MPV with some icebreaking ability.

It might make sense for the USCG to buy AIVIQ at a modest price of perhaps $25 to $50 million with a budget of no more than $10 million and one year for conversion. It could play a stopgap Alaska icebreaking and rescue towing role at reasonable cost while we wait for a real icebreaker to be built and funded.[/QUOTE]

Yes, and either way eventually it could be utilized as a naval asset to replace one of the USNS tugs and add DP/ice capabilities at the same time.


#8

“Some” being a design icebreaking capability of 5 knots in 3.3 ft ice, more than that of many “real” icebreakers. Of course, with mechanical powertrain and CP propellers in nozzles, the overall operational capability in ice may leave much to hope for.


#9

[QUOTE=tugsailor;177731]I wouldn’t call AIVIQ either a heavy or medium icebreaker. It’s just an unproven MPV with some icebreaking ability.[/QUOTE]

I do have to wonder if Shell ever did have the AIVIQ crunch any ice when in the Arctic to see what she was truly capable of with regards to icebreaking?


#10

[QUOTE=z-drive;177728]I didn’t get that impression from the report. Too small and leasing offers no savings and actually costs more over the ships life. Short term, yes.[/QUOTE]

you know of course that the USCG would never want to lease somebody else’s ship and want to own their outright but the Congress would have to appropriate the money for a new purpose built ship and with strong lobbying by ECO then might tell the Coast Guard to suck it up and take the ship they are given.

One thing in the report regarding the leasing of a commercial ship was that they keep saying that no vessels are presently available which makes me wonder if all this was written before Shell pulled the plug on their Arctic adventures? We certainly now know that the AIVIQ is out of a job and being the massive moribund Blue Whale she is will never go back to work in the offshore industry (big shoutout to Shell for that bit of genius) so logically, if the USCG needs a ship which can break ice and ECO is sitting on one not doing anything other than propping up a dock then you put the pieces together and tell me how they fit?


#11

perhaps in an interim manner, but they will not just plan to lease indefinitely. The report seemed to say leasing was an option but not practical for a “heavy icebreaker”


#12

[QUOTE=Tups;177742]“Some” being a design icebreaking capability of 5 knots in 3.3 ft ice, more than that of many “real” icebreakers. Of course, with mechanical powertrain and CP propellers in nozzles, the overall operational capability in ice may leave much to hope for.[/QUOTE]

The Louisiana companies routinely exaggerate horsepower by 50%, so why wouldn’t they also exaggerate icebreaking ability?

If they did not know any better than to use nozzeles, why would we think they know anything about building an icebreaker or what it’s actual capabilities might be?

I have to wonder how long she would hold together if routinely used for icebreaking duty.

I agree with c.captain, they should have steamed AIVIQ a couple hundred miles north of the iceless Chukchi Sea drilling site and tried her out in one meter of actual sea ice with ridges.


#13

I think they left all of the real icebreaking work for the Finnish icebreakers. They couldn’t risk another mishap, eh … especially after Fennica’s hull incident (not ice related though)?


#14

Saw Aiviq tied up in Seattle today STILL.


#15

[QUOTE=commtuna;177788]Saw Aiviq tied up in Seattle today STILL.[/QUOTE]

and there she will remain for a very long time although you have to wonder that the USCG Pier 37 where their icebreakers moor is just across Elliot Bay


#16

I can’t see the uscg buying that thing but you never know I guess


#17

tugsailor, most “offshore icebreakers” have nozzles. Even the Swedish icebreaking phenomenon Oden features a similar propulsion system as Aiviq. However, nozzles are known to cause problems (clogging) even in diesel-electric Z-drive ships like Fennica and Nordica, so there’s a definite loss of overall operational capability in difficult ice conditions especially for conventional shaftline ships that cannot “blow” the nozzles open. This is apparent with Oden when she’s being used for escort operations in the Baltic Sea - despite her fame as one of the best icebreakers in the world, she’s better off in operations such as the McMurdo break-in and scientific stuff in the Arctic than cutting icebound ships free on the Swedish coast.

As we all know, the advantage of nozzles is that the vessel has much higher bollard pull in open water for towing and anchor-handling operations. Unless you expect to do a lot of ice management and other challenging operations in difficult ice conditions, you’re better off with ducted propellers. However, in my opinion azimuth thrusters are something you can’t really do without if you want to do serious icebreaking. Perhaps that’s why ECO chose them for the two icebreaking AHTS vessels that it was (is?) building…

As for the icebreaking performance, it’s possible to calculate a rough estimate based on publicly available technical data and a few drawings from Shell’s ice management plan. I might actually have my students use Aiviq in their weekly exercises later this spring. Also, being a new design, it has probably been tested in an ice tank. I would expect that Shell has asked to see the model test report before paying for the vessel.

I, for one, would have wanted to see Aiviq break some ice. When I was up there in 2012, the ice around Kulluk was barely thick enough to walk on.


#18

[QUOTE=rshrew;177815]I can’t see the uscg buying that thing but you never know I guess[/QUOTE]

it would happen if the Congress forced them to take it but you know there would be lots of kicking and screaming in the process. I can certainly see ECO putting on a full court lobbying press with all their friendly Alaska delegation to make this happen and if Uncle Ted was still alive and leader of the Senate Appropriations Committee that the money would already be a approved and ready to go. It would not even surprise me it they got the deal set up to keep ECO people on the vessel after it want to the USCG.

what I want to know is if Shell is still paying the charter rate on the Whale or if they have given Chouest a lump sum to buy out the contract?

      • Updated - - -

[QUOTE=Tups;177816]tugsailor, most “offshore icebreakers” have nozzles. Even the Swedish icebreaking phenomenon Oden features a similar propulsion system as Aiviq. However, nozzles are known to cause problems (clogging) even in diesel-electric Z-drive ships like Fennica and Nordica, so there’s a definite loss of overall operational capability in difficult ice conditions especially for conventional shaftline ships that cannot “blow” the nozzles open. This is apparent with Oden when she’s being used for escort operations in the Baltic Sea - despite her fame as one of the best icebreakers in the world, she’s better off in operations such as the McMurdo break-in and scientific stuff in the Arctic than cutting icebound ships free on the Swedish coast. [/QUOTE]

don’t all these ships have some form of screen forward of the Kort nozzles to prevent ice from getting into the prop? If they don’t…why not?


#19

[QUOTE=c.captain;177817]don’t all these ships have some form of screen forward of the Kort nozzles to prevent ice from getting into the prop? If they don’t…why not?[/QUOTE]

While some ships such as the Russian nuclear-powered lighter Sevmorput have hull appendages to steer bigger ice floes away from the nozzle, I have never seen any kind of “screens” in front of the nozzles in large icebreakers. I would expect something like that to cause more problems than it solves - it would get clogged very quickly by small pieces of ice, disturbing the flow to the propeller and thus reducing the thrust.

Keep in mind that the propeller blades are designed to withstand nearly constant ice contact as long as the propeller keeps turning and the blades hit the ice floes with the leading or trailing edge - there’s no need to “protect” them. However, when nozzles get clogged, the propeller slows down. In diesel-electric vessels, you get full torque from (nearly) zero speed and the propulsion motors can also provide over 100% of nominal torque for a brief period of time, meaning that the propulsion system recovers faster and can generally deal with a lot more ice contact. While some diesel-mechanical icebreakers feature flywheels on the shaft to increase inertia, there’s only that much torque that a diesel engine can provide at low revolutions. That’s one of the main reasons why icebreakers went from steam engines to diesel-electric propulsion.

Here’s a video of some TransAtlantic icebreakers (shaftlines, CPP, nozzles, mechanical powertrain - not unlike Aiviq!) being completely helpless in difficult ice conditions in the Baltic Sea. They had to call in the 1970s era quad-screw diesel-electric icebreakers to help them and the passenger ships.

//youtu.be/QgWo1uCu-RA


#20

I figured they would sell the notion that the aviq should be positioned in Prince William Sound as a ice mangment/ response vessel. I know the servs contract should be getting renewed shortly.