Gerald R. Ford Class CVN

[Firefinder]

Good thing that the Ford was to have an AC IEP system like the Zumwalts.

So literally half of the issue mentions are not even a thing

 

[DJK]

Then there's the brushes...

Carbon everywhere. It takes forever to clean the motor and generator of it and you end up covered in that...@#$%@#&^**

Lucky modern DC motors should be brushless these days, I cant imagine how often you would have to replace brushes on a propulsion motor!

 

[T. A. Gardner]

Lucky modern DC motors should be brushless these days, I cant imagine how often you would have to replace brushes on a propulsion motor!

Motors that would drive a ship have brushes. The generators have brushes. I hate brushes... You get that way when you're the one having to do the maintenance on them. They work better if you are going to cruise at a fixed speed and that speed isn't particularly high.

 

[TomS]

Good thing that the Ford was to have an AC IEP system like the Zumwalts.

So literally half of the issue mentions are not even a thing

I don't think Ford was ever planned to have IEP.

 

[TomS]

Motors that would drive a ship have brushes. The generators have brushes. I hate brushes... You get that way when you're the one having to do the maintenance on them. They work better if you are going to cruise at a fixed speed and that speed isn't particularly high.

The Zumwalts use induction motors for propulsion. No brushes.

I'm not 100% certain, but I think all the rotating machinery was designed to be brushless, for this very reason.

 

[T. A. Gardner]

The Zumwalts use induction motors for propulsion. No brushes.

I'm not 100% certain, but I think all the rotating machinery was designed to be brushless, for this very reason.

Yes, that's possible. They may be AC stepper motors with variable frequency. It all adds complexity though.

 

[DJK]

Yes, that's possible. They may be AC stepper motors with variable frequency. It all adds complexity though.

Pretty sure they were AC induction motors designed to run off a massive VFD (variable frequency drive). Usually there is various strategies to control speed/acceleration via the VFD, but I found one concept interesting that allows the VFD to approximate torque output so that would have been a useful thing for military propulsion. One comment I remember vaguely was that PMM motors weren't available in time, and some rumour that DoD was trying to avoid relying on rare earth magnets that would be vulnerable to supply issues from China. Big VFDs became feasible a while ago after a certain component was developed that could handle the power.

 

[Sferrin]

JFK.