055 DDG Large Destroyer Thread

[Brumby]

Electric drives were used on naval ships a hundred years ago and so the idea itself is not new. Rather than adopting a jones mentality, the question to ask is why do you need it for your naval ship?


Essentially the conversation over electric-drive technology centers around the type of electric motor. Synchronous motor is technologically the most matured and I believe are the ones installed on commercial vessels. I think the hybrid system used in Burkes feature synchronous motor as an approach due to its power-density limitation There is a problem in scaling up and is not entirely suitable for power-dense military naval vessels. Next in line in technological maturity is the induction motor which is sufficient in power-density for naval surface vessels but not submarines because of compactness and noise. I think this is what went into the Zumwalt if I am not mistaken. Next up is the permanent magnet motor which is considered suitable for both surface and underwater vessels. I suspect this will go into the Ohio next generation vessel. For the even more technologically challenging is the superconducting synchronous motor and the superconducting homopolar motor. If China is working on IEPS, does anyone know which electric motor it is working on?

 

[Brumby]

Sometimes there is price to pay for being an early adopter when the technology is not matured. The Type 45 electrical problems as reported earlier this year.

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Repeated electrical faults have left £1bn Type 45 destroyers unable to navigate or activate weapons systems
The Royal Navy’s most advanced warships, once described as the best in the world, will need multimillion-pound repairs because of repeated power failures that leave the Type 45 destroyers unable to move or use defence and weapons systems.

The technical faults, initially described by the

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as a short-term problem, will require engineers to bore holes in the sides of the six £1bn warships to add new generators.

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that a senior serving naval officer had written in an email that “total electric failures are common” on the ships. Two years ago, HMS Dauntless had to stop a training exercise because of power failure, and in 2009, on its first voyage to the US, HMS Daring lost power in the Atlantic.

The former Labour security minister Admiral Lord West called the flaw “a real weakness” and said the MoD had pretended it was a case of teething problems.
“They must have known three or four years ago that this was more than that,” he

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. “There’s no doubt this is extremely worrying. It’s an intermittent fault which has quite clearly caused a lot of problems. You don’t expect suddenly to lose all power when you’re steaming along normally.”

West said the repairs were likely to cost huge sums. “Tens of millions, because you’ll have to cut a hole in the ship, get into it, fit something else into it, button it up and get it out. And even more worrying is we only have 19 destroyers and frigates. That is a national disgrace. Someone needs to look at why did we arrive at this position.”

An MoD spokesman said last year’s defence review had committed to improving the Type 45’s power and propulsion system through a series of machinery upgrades during planned maintenance.

 

[delft]

Brumby's post shows two Rotterdam LPD's. These ships have now be replaced by the single Joint Logistics Ship Karel Doorman. This ship had one of its two pod mounted e-motors fail at sea at less than one year after commissioning. Repairs will cost some eight months.

 

[damitch300]

Err no.
We still have boths lpds.
Johan de with one of them has pods.
Karel doorman got 2 electric drive engines with normal screws.
One engine broke down for the repair of 8months.

 

[damitch300]

Brumby's post shows two Rotterdam LPD's. These ships have now be replaced by the single Joint Logistics Ship Karel Doorman. This ship had one of its two pod mounted e-motors fail at sea at less than one year after commissioning. Repairs will cost some eight months.

Err no.
We still have both lpds.
Johan de witt and Rotterdam.
Johan de witt is one of them and has pods.
Karel doorman of an jss class got 2 electric drive engines with normal screws.
One engine broke down for the repair of 8months.

 

[ShattaAD]

Would it be possible/feasible for future DDGs like the 055X to have a fully enclosed aft helo deck/hangar hybrid AIO so as to eliminate the need for a dedicated hangar and a dedicated landing platform for the helos? The hangar enclosure can fold out like a convertible or a mobile bridge platform to increase deck space if needed be or when launching the helo. I can see several advantages to this design, it can increase the usable space for say, VLS by eliminating the current hangar location on the 052x. It can also improve stealth by making the aft section more uniform along with the rest of the ship and it can launch and recover helos much faster than having to roll them out of the hangar first since the hangar is also the launch platform for the helo.

 

[AndrewS]

Isn't the hanger where they store equipment and do maintenance as well?

Plus I expect the importance of UAVs to grow in the future, so they should build in more expansion space.

 

[Blitzo]

an interesting depiction (this is the highest quality version i could find) -- though I think the cutaway gets quite a few things wrong which will probably be different on the real thing. certain sensors missing or present which shouldn't be, low VLS count, and other configuration deviations.

But overall it's a nice cutaway, from warship knowledge magazine I think... though I think given their track record they are shooting in the dark sometimes as much as we are despite being semi official.

 

[MwRYum]

Would it be possible/feasible for future DDGs like the 055X to have a fully enclosed aft helo deck/hangar hybrid AIO so as to eliminate the need for a dedicated hangar and a dedicated landing platform for the helos? The hangar enclosure can fold out like a convertible or a mobile bridge platform to increase deck space if needed be or when launching the helo. I can see several advantages to this design, it can increase the usable space for say, VLS by eliminating the current hangar location on the 052x. It can also improve stealth by making the aft section more uniform along with the rest of the ship and it can launch and recover helos much faster than having to roll them out of the hangar first since the hangar is also the launch platform for the helo.

Dedicated hanger is a necessity because helicopter need not only a sheltered storage onboard, but also to have the said space be served as its garage for lower-tier level maintenance, thus you'd find gantry crane a common feature there, on all ships that has helicopter hanger. Any "convertible" enclosure not only has structural and durability issues in the long run (just the fact that the enclosure was broken, leaving it stuck at half-open position, would render the flight deck unusable right there, and worse such repair would definitely require dock facility), perhaps even fire hazard. Also, the walls on such a structure is simply dead-weight because they couldn't be utilized for other purposes, whereas standard hanger structures you'd find its walls and ceilings are utilized for storage as well.

Never underestimate Murphy's Law, and certainly don't give it a chance.

 

[dingyibvs]

Dedicated hanger is a necessity because helicopter need not only a sheltered storage onboard, but also to have the said space be served as its garage for lower-tier level maintenance, thus you'd find gantry crane a common feature there, on all ships that has helicopter hanger. Any "convertible" enclosure not only has structural and durability issues in the long run (just the fact that the enclosure was broken, leaving it stuck at half-open position, would render the flight deck unusable right there, and worse such repair would definitely require dock facility), perhaps even fire hazard. Also, the walls on such a structure is simply dead-weight because they couldn't be utilized for other purposes, whereas standard hanger structures you'd find its walls and ceilings are utilized for storage as well.

Never underestimate Murphy's Law, and certainly don't give it a chance.

Certainly there are downsides, but wouldn't they be greatly offset by the huge amount of space saved? I mean, I'm sure putting a whole new type of VLS on the 052Ds has plenty of risks involved, but it's done because of the significant benefits they bring. I can't imagine risks associated with the reliability of a door or rearrangement of the garage space are significant enough to outweigh the benefits of saving enough space to add another 32-64 VLS.