Video on Azipod Propulsion on RCI

[mjldvlks]

My understanding was that they installed a single diesel engine on Radiance class ships to provide electricity primarily when the ship was in port. The turbines still provide power when the ship is at sea. I believe it was a cost saving measure, as the turbines were not as fuel efficient as the diesel engines at the lower power levels used in port.

 

You are correct. I heard somewhere, sometime that I cannot now recall, that turbines make good sense for propulsion but are way inefficient for generating electricity in port -- hence the addition of the additional engine for electrical generation.

 

There was a film about this in season one of Nat Geo's "World's Toughest Fixes" where they show the whole process from entering dry dock to cutting the hole in the side to installing the engine to re-sealing the hole. It used to be available on You Tube, but appears to have been taken down due to copyright complaints. If you ever get a chance, it is worth watching -- but I don't think I would pay Amazon whatever they want for it.

Edited June 18, 2014 by mjldvlks

[TheInnocentAge]

For example Allure has the following Diesels installed;

 

3 ×18,590 hp Wärtsilä 12V46D

3 ×24,780 hp Wärtsilä 16V46D

 

That's 6 engines the size of double-decker buses, producing a total of 130,000 HP. Just three marine turbines that would probably take up the space of three of those engines could produce the same power, if not much more.

 

The GE LM6000 marine turbine: 60,000 HP

 

Cool info, thanks for sharing. I was on the Allure last November shortly after her propulsion issues came to light, and although she was slowed a bit, it was still a very enjoyable cruise. Lost an hour or two of port time, so I'm sure those that had shore excursions impacted may have a different view of it than I.

[Tosara21]

Interesting video, thanks for sharing

[Psycopuppy]

The Navy used a lot of GE LM2500's for main propulsion systems and Allison 501K-17 & 34's turbines for electrical generation. The main turbines were all enclosed and if a new one was needed, they pulled it out of the air intake. Takes about 10 hours and can be done pier side.

 

I liked the pods as I see the ease as to move a ship that size. The Navy actually uses a reversible pitch implementation on the screws to adjust the thrust so that the shaft continues the same direction and allows the ship to move forward, reverse or neutral, but don't have the ability to have any side thrust. Of course, the ships have their own purpose in life.