055 DDG Large Destroyer Thread

[Iron Man]

The 78MW for the Zumwalt is what the drive motors driving the shafts can produce, the total output from the gensets is more, given its non-standard hull form it's probably all needed to get to flank. The QE "only" has 80MW driving it's props because the largest induction motors they had were 20MW ones and because of penny pinching it only has 2 shafts (can only shove so much power down a shaft) they used a bulbous bow to get it's top speed to a nominal 26kt adequate but would need an extra shaft to get past 30kt.

Hull form rather than displacement plays a big part in a ships speed a 40+K ton Nelson class battleship got tp 23kt with just 34MW! but I digress, Don't think they'll get away with just 2 QC-280s (56MW minus generation and transmission losses means robbing a 10MW from elsewhere) so probably need at least 3 (easily doable since they aren't hooked up to a shaft) but that really depends on what size electric motors they have, no point generating excess that can't be consumed, conversely no point not fitting enough. They could swap out a couple of the QC-280s for diesels which are more flexible (don't have to run them a full tilt to be efficient) but for maintenance probably easier to stick with all GTs.

Actually 78MW is the sum of the power ratings of all the power-generating units on the Zumwalt, not what is being outputted from the induction motors. As for hull form, the 055's very standard hull form is certainly far more efficiently designed for speed than the Zumwalt, the Daring, or the QE. The Daring can go 30+ knots with two 20MW induction motors. Possibly the 055 can accomplish the same with two 20MW induction motors, given its significantly higher L:B ratio (8.67:1 vs 7.19:1). Or maybe two 25MW motors. Both should be within the limits of two QC-280s, leaving the smaller GT generators to supply power to the rest of the ship.

 

[hkbc]

Actually 78MW is the sum of the power ratings of all the power-generating units on the Zumwalt, not what is being outputted from the induction motors. As for hull form, the 055's very standard hull form is certainly far more efficiently designed for speed than the Zumwalt, the Daring, or the QE. The Daring can go 30+ knots with two 20MW induction motors. Possibly the 055 can accomplish the same with two 20MW induction motors, given its significantly higher L:B ratio (8.67:1 vs 7.19:1). Or maybe two 25MW motors. Both should be within the limits of two QC-280s, leaving the smaller GT generators to supply power to the rest of the ship.

Well if it could do the necessary speed with a pair of 25MW (50MW total) motors then it's a bit odd that they felt the need for 4 QC-280s ~112,000 MW (twice the amount) in the current direct drive setup. Electric motors have much better torque characteristics but doubt the gearboxes in the direct drive system is going to make 50% of the delivered power evaporate. Not here to pick a fight but the numbers don't seem to stack up, unless the 055 is presently grossly over powered and the IEP presents an opportunity to correct that.

 

[jobjed]

Well if it could do the necessary speed with a pair of 25MW (50MW total) motors then it's a bit odd that they felt the need for 4 QC-280s ~112,000 MW (twice the amount) in the current direct drive setup. Electric motors have much better torque characteristics but doubt the gearboxes in the direct drive system is going to make 50% of the delivered power evaporate. Not here to pick a fight but the numbers don't seem to stack up, unless the 055 is presently grossly over powered and the IEP presents an opportunity to correct that.

The 055 in its present form has about 30-40% more power than the Burke while also being 40% heavier. That seems pretty normal and in-line with the rest of the world. Whether it'll keep all four turbines when switching to IEP is another question altogether.

 

[Iron Man]

Well if it could do the necessary speed with a pair of 25MW (50MW total) motors then it's a bit odd that they felt the need for 4 QC-280s ~112,000 MW (twice the amount) in the current direct drive setup. Electric motors have much better torque characteristics but doubt the gearboxes in the direct drive system is going to make 50% of the delivered power evaporate. Not here to pick a fight but the numbers don't seem to stack up, unless the 055 is presently grossly over powered and the IEP presents an opportunity to correct that.

I think the numbers fit personally. By way of an example, the Type 45's total power generation capacity is 47MW. Assuming you need 7MW for electrical systems, that's 40MW left for propulsion. A non-IEP version of the 8,500t Daring should require maybe double that number for propulsion. Incidentally the Ticonderoga cruisers use four (early generation) LM-2500s to generate ~100MW power purely for propulsion, so 112MW is certainly well within expectations for a 055 (perhaps even somewhat less than expectations).

 

[hkbc]

I think the numbers fit personally. By way of an example, the Type 45's total power generation capacity is 47MW. Assuming you need 7MW for electrical systems, that's 40MW left for propulsion. A non-IEP version of the 8,500t Daring should require maybe double that number for propulsion. Incidentally the Ticonderoga cruisers use four (early generation) LM-2500s to generate ~100MW power purely for propulsion, so 112MW is certainly well within expectations for a 055 (perhaps even somewhat less than expectations).

Not really the near cousin of the type 45 the Italian/French horizon class uses a pair of LM2500 GTs that delivers 20.5MW each, for roughly the same speed they displace a little less and have a little less beam but trace their origins to a common program so have similar hull forms. In that instance it certainly doesn't need twice the installed power and is arguably a better data point than any comparisons with US designs!

Besides my point is that IMO 40MW or even 50MW is a bit light to push the 055 around at the same speed, if it needs 60MW then you'll need another GenSet, it's not like there isn't the space for it!

BTW the Type 45 is at the margins of its power generation envelope and there's a program in place (project napier) to add an additional diesel generation capacity to make it more reliable.

 

[Max Demian]

While 112 MW is a lot, it is not unheard of for a ship of this size. Besides Ticonderoga, another example would be the Udaloy class. At 8kt displacement it has 90MW of propulsion power from its GTs enabling it to hit 35 knots at flank speed.

 

[Jura The idiot]

LOL people I have no idea where this 'power' discussion is heading, just please don't arrive at USN LCSs which have about as much power as dozen times more displacing

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had (I checked several years ago), but are politically engineered JUNK

 

[asif iqbal]

What we want to see is a heavy surface action group (SAG) made up of 4 x Type 055 supplied by a fast Type 901 tanker

5 ship formation SAG moving at high speed 30 + knots into Bering straight through into Pacific and Alaska

Bet that would send shivers down spine of most navy’s

In addition it would have USN pulling a lot of resources tagging these units and keeping up

A good show of force with ultra modern warships carrying serious firepower

 

[Yodello]

What we want to see is a heavy surface action group (SAG) made up of 4 x Type 055 supplied by a fast Type 901 tanker

5 ship formation SAG moving at high speed 30 + knots into Bering straight through into Pacific and Alaska

Bet that would send shivers down spine of most navy’s

In addition it would have USN pulling a lot of resources tagging these units and keeping up

A good show of force with ultra modern warships carrying serious firepower

That would be awesome...! The US shouldn't be the only one sailing into everyone else's backyard at it's whim and fancy. Give it another 5 to 7 years and we'll definitely see the PLAN warships traversing the Pacific and the US Coast. That will be a heartwarming sight....!

 

[Iron Man]

Not really the near cousin of the type 45 the Italian/French horizon class uses a pair of LM2500 GTs that delivers 20.5MW each, for roughly the same speed they displace a little less and have a little less beam but trace their origins to a common program so have similar hull forms. In that instance it certainly doesn't need twice the installed power and is arguably a better data point than any comparisons with US designs!

Besides my point is that IMO 40MW or even 50MW is a bit light to push the 055 around at the same speed, if it needs 60MW then you'll need another GenSet, it's not like there isn't the space for it!

BTW the Type 45 is at the margins of its power generation envelope and there's a program in place (project napier) to add an additional diesel generation capacity to make it more reliable.

Nope. The LM2500+ actually delivers 30.2MW each for a total of 60.4MW. Not to mention the Horizon is 1,500t lighter than the Type 45.