055 DDG Large Destroyer Thread

[Blitzo]

My point was that it would be impossible to achieve the same top speed if you halved the amount of GTs, as someone suggested, so you can fit the magic number of VLS. Even with IEPS the efficiency gain is not going to be the 50% required. Gearboxes, even high speed ones, are not that inefficient. The other point was that IEPS is not physically smaller than a traditional configuration (there are some reports of the opposite concerning the Zumwalt class). So you won't be able to fit everyones favorite number of VLS just by going over to IEPS and keeping everything else the same.

I currently have no opinion about the 128 VLS number. For all we know the IEPS variant of 055 might keep 112 VLS because that number is what the PLAN deemed to be sufficient in the first place.
I also have no opinion about whether an IEPS variant of 055 with 2 vs 4 QC-280s may have more, same or less space to work with than the current 055 arrangement.

However, halving the number of QC-280 gas turbines from four to two and allowing the ship to achieve the same speeds, while using IEPS, I think isn't very ridiculous as the Type 45 example shows with WR-21. Considering 055 has likely 6 auxiliary gas turbines as well, which could be retained in a hypothetical IEPS variant, that will give the ship additional powerplants.

 

[AndrewS]

I currently have no opinion about the 128 VLS number. For all we know the IEPS variant of 055 might keep 112 VLS because that number is what the PLAN deemed to be sufficient in the first place.
I also have no opinion about whether an IEPS variant of 055 with 2 vs 4 QC-280s may have more, same or less space to work with than the current 055 arrangement.

However, halving the number of QC-280 gas turbines from four to two and allowing the ship to achieve the same speeds, while using IEPS, I think isn't very ridiculous as the Type 45 example shows with WR-21. Considering 055 has likely 6 auxiliary gas turbines as well, which could be retained in a hypothetical IEPS variant, that will give the ship additional powerplants.

In the next refit for the current Type-55 class, aren't those 6 auxiliary gas turbines going to become the primary power source for future railguns?

I can see them taking out the 130mm Gun and some of the VLS, in order to fit 2 railguns instead. That still leaves a large number of VLS cells.

And in terms of power requirement, a 32MJ railgun which fires 10 rounds per minute requires a 5.3MW electricity source

 

[taxiya]

I don't inherently disagree with what you wrote, however I'd like to refer back to the original point of contention that spurred this discussion, which were two posts that suggested an IEPS configuration was "less efficient" than a conventional arrangement of gas turbines to shafts via reduction gears and the idea that IEPS would somehow be unable to achieve that top speed.

https://www.sinodefenceforum.com/type-055-ddg-large-destroyer-thread.t6480/page-606#post-521822



The reason why Type 45 is brought in, IMO, is to demonstrate that when IEPS configuration is working, that it is able to propel the Type 45 to its intended speeds and at a satisfactory level of efficiency.

Issues with the Type 45's IEPS and in particular the powerplants driving the IEPS do of course exist, however that is largely immaterial to the original area of disagreement, which was whether IEPS could allow a ship to reach its intended top speeds and/or do so efficiently.

Yes, I agree bringing in Type 45's issues was bit distraction to the original point.

 

[vincent]

In the next refit for the current Type-55 class, aren't those 6 auxiliary gas turbines going to become the primary power source for future railguns?

I can see them taking out the 130mm Gun and some of the VLS, in order to fit 2 railguns instead. That still leaves a large number of VLS cells.

And in terms of power requirement, a 32MJ railgun which fires 10 rounds per minute requires a 5.3MW electricity source

Why not just build a dedicated railgun ship with 3-4 railguns and operates within a fleet? Let the 055 defend the air

 

[taxiya]

My point was that it would be impossible to achieve the same top speed if you halved the amount of GTs, as someone suggested, so you can fit the magic number of VLS. Even with IEPS the efficiency gain is not going to be the 50% required. Gearboxes, even high speed ones, are not that inefficient. The other point was that IEPS is not physically smaller than a traditional configuration (there are some reports of the opposite concerning the Zumwalt class). So you won't be able to fit everyones favorite number of VLS just by going over to IEPS and keeping everything else the same.

Gearbox efficiency is not the biggest issue, nor an important issue. It is the deficiency of high RPM propeller at low speed acceleration and maneuver. That deficiency of direct drive demands the large power headroom (excessive) compared to the power demand at straight line top speed.

 

[Iron Man]

My point was that it would be impossible to achieve the same top speed if you halved the amount of GTs, as someone suggested, so you can fit the magic number of VLS. Even with IEPS the efficiency gain is not going to be the 50% required. Gearboxes, even high speed ones, are not that inefficient. The other point was that IEPS is not physically smaller than a traditional configuration (there are some reports of the opposite concerning the Zumwalt class). So you won't be able to fit everyones favorite number of VLS just by going over to IEPS and keeping everything else the same.

Not impossible, for reasons already mentioned. Second, let's not forget the 6 GT generators which could easily be upgraded in future iterations of the 055. Finally, I'm not suggesting that the 055 will definitely have >112 VLS cells in the future, only that this possibility exists. And it does.

 

[AndrewS]

Why not just build a dedicated railgun ship with 3-4 railguns and operates within a fleet? Let the 055 defend the air

The railgun projectiles should be able to perform low-cost air defence in addition to anti-surface.

At a minimum, it should make sense to replace the 130mm Gun with a railgun at the next refit.

 

[vincent]

The railgun projectiles should be able to perform low-cost air defence in addition to anti-surface.

At a minimum, it should make sense to replace the 130mm Gun with a railgun at the next refit.

We are talking about hitting bullet with a bullet here, literally. Railgun's projectile is unguided too, with low firing rate compare to 1130. Hard to see how useful it can be at anti-air

 

[Sczepan]

1th sea trial

 

[Jura The idiot]

1th sea trial View attachment 48637 View attachment 48638

Sczepan
are you frigging serious?!

Type 055 DDG Large Destroyer Thread Aug 24, 2018

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Type 055 DDG Large Destroyer Thread Aug 25, 2018

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