gCaptain has posted news of a new propulsion system developed by Caterpillar Marine in partnership with Odense Maritime Technology (OMT) and Scandinavian Marine Group (SMG) that is claimed to be more efficient, quieter, and suitable for icebreakers and other vessels operating in severe environment, while offering maintenance advantages in terms of accessibility. A more complete view of the system is here.
Seems like an overly complicated design. What’s wrong with Azipods and Z-drive thrusters?
Also, I still don’t understand why people insist on putting nozzles to ice-going vessels…
The supposed advantages include the ability to do maintenance on the system without going into dry dock.
As to the nozzles, supposed to increase “thrust” not speed, meaning I believe better towing ability, and perhaps better acceleration. Nozzle rings might keep the bigger chunks of ice out of the screws, although might also provide place for ice to accumulate.
Well, I do see a point in the maintenance aspect. However, there are also a lot more components to fail in comparison to an electric podded propulsion unit. Sure, you need a dry dock (or one of those boxes that can be pumped dry to form a “partial” dry dock) to carry out maintenance, but operational experience from Arctic applications has shown that “extra” drydockings are rarely needed.
As for the nozzle, I know what the advantages are, but not that many people know just how bad the ice clogging can be even in well-designed ships and how it affects the performance of the vessel. That’s why I would never put a ducted propeller to a vessel intended for operations in ice (icebreakers, ice management vessels etc.).
However, perhaps this kind of propulsion system could find its niche in marginal ice zone applications.
Azipods seem so much better than this to me. Ability to direct thrust and/or wash/turbulence in any direction are far superior for the Azipod than this. With the size depicted in the drawing, there’s also going to be a significant tunnel between the housings. And, I’m not an MK by any stretch of the imagination, but other than seals, what would need to be worked on, which could also be accessed from inside, when we’re talking about electric motors (which I was under the impression were not maintenance-intensive)?
gCaptain reports the system got an innovation award. There is also a claim of a 30 improvement in efficiency. http://gcaptain.com/cat-twin-fin-system-wins-innovation-award/
More on this system: http://www.marinelog.com/marine-log-news/item/10364-cat-twin-fin-system-wins-platts-global-energy-award.html