Catobar Chinese carrier

[skyrover]

China has announce construction of it's third aircraft carrier and first CATOBAR carrier has begun with first steel cut in march 2015.

http://www.bilibili.com/video/av7611144/



The construction of a 4th carrier may also have started.

[Lurking Lawyer]

DELETED: Comment made by a member who's account has been deleted.

I can't see it either but I suspect it won't be EMALS.

Then again, they nick everything else so you never know!

[Eric Mc]

EMALS?

Wild Guess - Electro-Mechanical Air Launch System?

[Eric Mc]

All the early steam catapult ships were non-nuclear.

[maffski]

They've updated their test facility with one steam and one EMAL's catapult.

China flight testing modified J-15 for CATOBAR operations

[Eric Mc]

What do they use today - gas turbines I suspect?

[Eric Mc]

So, In English - it has gas turbines combined with diesel generators but the propellers are turned by electricity?


Seems a bit overly complicated to me. How is this more efficient than say, gas turbine turned screws or even direct diesel turned screws?

I would have thought introducing so many stages into the power delivery system would introduce power losses.

Perhaps someone could enlighten me

[tuffer]

Eric Mc said:

So, In English - it has gas turbines combined with diesel generators but the propellers are turned by electricity?


Seems a bit overly complicated to me. How is this more efficient than say, gas turbine turned screws or even direct diesel turned screws?

I would have thought introducing so many stages into the power delivery system would introduce power losses.

Perhaps someone could enlighten me

Wild guess, would you get more Torques from electric motors?

[SpeckledJim]

Or, you can run your gas turbines at an optimised steady, efficient rate, and then the electricity you garner is used as and when and how you need it?

[saaby93]

SpeckledJim said:

Or, you can run your gas turbines at an optimised steady, efficient rate, and then the electricity you garner is used as and when and how you need it?

Could they use that idea on some recent RN ships too?

[Taffer]

Eric Mc said:

So, In English - it has gas turbines combined with diesel generators but the propellers are turned by electricity?


Seems a bit overly complicated to me. How is this more efficient than say, gas turbine turned screws or even direct diesel turned screws?

I would have thought introducing so many stages into the power delivery system would introduce power losses.

Perhaps someone could enlighten me

With mechanical systems, you have losses in the propeller shaft and the reduction gearboxes, plus the space they take up in the ship. You're not adding stages into the power delivery system with diesel-electric (no need for gearboxes or outputs to shaft generators) and you're introducing the benefits of increased redundancy (several power sources feeding into the system).

Not used for military purposes, but diesel(and GT, thanks Cunard)-electric azipod propulsion systems have much less hydrodynamic drag, and have proven fuel savings over 'traditional' configurations on ships.

[Eric Mc]

Tanks for the explanation.

Are big diesels used much on naval ships?

[Taffer]

Eric Mc said:

Tanks for the explanation.

Are big diesels used much on naval ships?

Depends on your definition of big!

If you mean really big, slow-speed 2-stroke engines like those on container ships and tankers, then no. Plenty of large naval vessels with 4-stroke engines as prime movers though, HMS Ocean being one of the biggest I can think of without GTs (2x12000hp engines). Plenty of naval auxiliary vessels are just diesel too, as they have no requirement for bursts of high speed steaming.

[Steve_D]

DELETED: Comment made by a member who's account has been deleted.

Not unlike the days of steam where you only lit as many boilers as you needed at the time. When the bridge said they wanted more speed you lit more boilers.
Now you start another DG or GT and perhaps throw some switches.

Steve