052C/052D Class Destroyers

[Andy1974]

View attachment 168725
It is possible that later 052Ds are retrofitted with CGT30 according to an official interview posted a few days ago

Wow. So this means the gas turbine output goes from 28MW -> 33.5MW, or an extra 5.5MW per shaft, or 11MW in total?

That should have a nice impact on top speed, as well as improved reliability and extra power generation for sensors and weapons.

When do you think this was first introduced? Or, how many ships already have this new turbine?

Do you think the Type 055 also got this upgrade for its second batch?

 

[Tomboy]

Wow. So this means the gas turbine output goes from 28MW -> 33.5MW, or an extra 5.5MW per shaft, or 11MW in total?

That should have a nice impact on top speed, as well as improved reliability and extra power generation for sensors and weapons.

Though AFAIK they don't have IEP hence turbines are only for propulsion, I'm pretty sure they have separate turbo-generators. So it isn't as big of an upgrade as people think it is unless they also upgraded the generators.

 

[ACuriousPLAFan]

Wait what's a CGT-28 again?

Basically, from this news report screenshot:



Though yes, we do have very little solid information available for the CGT-28 for the time being, and unlike the CGT-30, we aren't even sure whether the CGT-28 will be adapted for marine propulsion usage.

Anyways the main speculation on CGT-30 is due to the fact that it is advertised to be able to directly replace GT-25000 without modification to the mounting system etc.

Well, this development would be golden indeed.

However, considering that Baotou was commissioned back in the final days of 2021, yet the article posted by SOYO from several days before mentioned that the new GT work happened only two years ago (i.e. sometime in 2024), it does sound rather odd for them to just swap out the CGT-25s from inside the ship hull (which would necessitate opening the deck and associated structures) and install CGT-30s for such a young DDG.

But then, I suppose the ship designers have already considered such upgrades before or during the construction stages of the ship.

 

[Andy1974]

Though AFAIK they don't have IEP hence turbines are only for propulsion, I'm pretty sure they have separate turbo-generators. So it isn't as big of an upgrade as people think it is unless they also upgraded the generators.

If the Type 052D with CGT-25 can do 30 knots then with CGT-30 it can do 31.85 knots..

The **Type 052D destroyer** achieves a reported maximum speed of **30 knots** using its two QC-280 gas turbines, each rated at **28 MW** (total installed gas turbine power = **56 MW**). This occurs in CODOG mode during high-speed runs, where the gas turbines provide the dominant power for sprint/top speed (the diesels are typically used only for economical cruising and are disengaged at max speed).

Your question asks for the theoretical top speed if those were upgraded/replaced with engines delivering **33.5 MW each** (total **67 MW**), using an exact calculation and holding all other factors constant (hull form, displacement ≈7,500 tons full load, wetted surface, propellers, etc.).

### Exact Calculation Using the Standard Admiralty/Propeller Law Approximation

For displacement hulls like modern destroyers at/near top speed, speed scales with the cube root of delivered power (v ∝ P^{1/3}), because resistance is dominated by wave-making drag in that regime, which rises roughly with the cube of speed.

- Original power per engine: 28 MW
- New power per engine: 33.5 MW
- Power ratio = 33.5 / 28 = **1.19642857**
- Speed ratio = (1.19642857)^{1/3} ≈ **1.061603** (exact cube root)
- New speed = 30 knots × 1.061603 ≈ **31.848 knots**

**Result: ≈ 31.85 knots** (rounded to two decimal places for practical naval reporting).

### Step-by-Step Derivation

1. Power ratio = 33.5 ÷ 28 = 1.1964285714285714
2. Cube root of power ratio = (33.5 / 28)^{1/3}
- First compute 33.5 / 28 = 1.1964285714285714
- Then 1.1964285714285714^{1/3} ≈ 1.061603 (you can verify this with any calculator or Python: `(33.5/28)**(1/3)` ≈ 1.061603)
3. 30 × 1.061603 ≈ 31.84809
4. Rounded: **31.85 knots** (or conservatively 31.8 knots if using fewer decimals).

This is a clean theoretical scaling assuming:
- The same propulsive efficiency (η),
- The same hull resistance curve shape,
- No major changes to propeller design, shafting losses, or sea state limits,
- The extra power can be fully absorbed and converted to thrust without cavitation or other limits being hit first.

In the real world, small upgrades like this often yield close to the predicted gain (a few percent more speed), but actual trials might show slightly less due to increased cavitation margins, gearbox limits, or minor hull/propeller mismatches. Still, **~31.8–31.9 knots** is a reasonable exact physics-based estimate for the hypothetical 2 × 33.5 MW case.

This is so typical of Chinas conservative upgrading, trying out one new piece of kit on an existing type before introducing it in a new type.

With the 054B China has tried new diesel engine, now with the 052D (and coast guard ships?) it has tried new gas turbines.

So for the next generation of ships combining diesel and gas it can have really strong confidence in the power plants. It’s a brilliant upgrade imo.

I think this development justifies increasing Type 052D numbers to 48, or more.

 

[AndrewS]

If the Type 052D with CGT-25 can do 30 knots then with CGT-30 it can do 31.85 knots..

With that sort of difference, it doesn't seem worth replacing the existing CGT-25 with a higher rated CGT-30.

There are only 3 aircraft carriers which would needs escorts with speeds of 30+ knots.
If they're building 20 new destroyers every 5 years, this would easily be enough escorts with the higher-rated gas turbines.

 

[ACuriousPLAFan]

With that sort of difference, it doesn't seem worth replacing the existing CGT-25 with a higher rated CGT-30.

There are only 3 aircraft carriers which would needs escorts with speeds of 30+ knots.
If they're building 20 new destroyers every 5 years, this would easily be enough escorts with the higher-rated gas turbines.

Because top speed isn't the only determining factor for executing such upgrades. Also, no warship sails at full speed the entire time.

For one, CGT-30M offers ~5MW of additional power compared to CGT-25M. Other than offering slightly higher maximum speeds, there are also added (and arguably more important) benefits of:
- Not having to operate at maximum power output all the time to achieve the same speeds as when operating the CGT-25Ms, if not allowing the derating of the engine to operate at the same power output as the CGT-25M (which also goes towards improving reliability and elongating engine life, albeit with only a small degree of penalty in efficiency (by about 1-2%));
- Enable the ship to retain better capability to sustain higher speeds in rough sea conditions (as it has an additional 5 MW per engine to push the ship through choppy waters); and
- Allows the ship to gain weight due to future upgrades while still able to sustain sailing at sufficiently high speeds (in case development efforts for subsequent variants similar to how the Burke DDGs evolved from Flight 1 to Flight 3 are needed for the 052D DDGs).

There's also the fact that 39.3% efficiency is actually a significant jump in fuel efficiency over the 35-36% efficiency (burning ~8.4% less fuel per kWh at full power, and ~6-7% less fuel per kWh when operating at the same power as CGT-25M, assuming using LHV with ~42.7 MJ/kg of energy density), especially considering that the increase in power output is only ~5 MW while not having a significant increase in volumetric and weight footprints on the 052D DDGs (as the CGT-30M is said to enable swap-in-swap-out upgrade over the CGT-25M).

In the long run (and expanded across the fleet), this will save a ton of material and money.

Furthermore, per SOYO - Baotou might be a one-off test and verification attempt in her (3rd) batch. The current latest (4th) batch of 052D DDGs could be the first (if not the only) batch in the class to adopt CGT-30M engines.

 

[ACuriousPLAFan]

Some more information on the switch to CGT-30M GTs on the newer 052D DDGs, by SOYO on Weibo.

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CGT-30M and the Improved Type 052D

Before the replacement, the main propulsion gas turbine for the Type 052D series was the GT25000 (also known as CGT-25M). The characteristics of this model can be summarized as follows:

1. Under ISO conditions (test temperature of 15°C), the rated maximum power of the CGT-25M marine propulsion variant is 28.7 MW. However, it is difficult to achieve this power level in actual shipboard use.

2. Under naval conditions (test temperature of 27°C), the rated maximum power of the CGT-25M marine propulsion variant is 24.26 MW. This is the theoretical power achievable in shipboard applications and is the power rating adopted in GJB (Chinese National Military Standards) and in papers and standards by various research institutes.

3. Under US NSD conditions (test temperature of 38°C), the estimated rated maximum power of the CGT-25M marine propulsion variant is only about 20 MW. Leaders from relevant institutes have also referred to the CGT-25 series as the "20 MW gas turbine" on multiple occasions.

From the above points, it can be seen that the CGT-25M is comparable to the basic LM2500 model equipped on the Burke-class destroyers, but cannot match the more powerful LM2500+. It also performs poorly in high-temperature environments, with average thermal efficiency, which may negatively affect the mobility of naval vessels in tropical regions.

The marine variant of the CGT-30 series—CGT-30M—was designed as "a new generation of domestically produced gas turbines intended to fully match the LM2500+." According to publicly available information, the technical features of the CGT-30M include:

1. Under ISO conditions (test temperature of 15°C), the rated maximum power of the CGT-30M marine propulsion variant is 32 MW, with a thermal efficiency exceeding 39%.

2. At an ambient test temperature of 31–32°C, the rated maximum power of the CGT-30M marine propulsion variant is 30 MW, demonstrating very stable power output capability in high-temperature environments.

3. The industrial variant of the CGT-30 series emerged as early as 2022, and energy-drive variants were exported in the past two years. According to promotional materials from its R&D institute, it has the capability for "in-situ replacement of the CGT-25."

Based on this, the possibility that the improved Type 052D has begun gradually retrofitting with the CGT-30M cannot be ruled out.

Even the improved Type 052D vessels commissioned in the last four years represent a significant number, serving as the backbone of the fleet for long-range deployments in the next decade. After retrofitting with the CGT-30M, the improved Type 052D will possess more robust total propulsion power, enabling it to conduct prolonged high-speed maneuvers in tropical high-temperature sea areas. This will allow the fleet greater flexibility in future deployments.

Previously, the surface combatant with the strongest high-speed performance/high-temperature sea area maneuverability in the fleet was the Type 055. However, the total number of Type 055 destroyers is limited. Deploying a Type 055 specifically to respond to high-speed maneuvering provocations from a Burke-class / Atago-class / Akizuki-class destroyer would be an excessive allocation of resources. In contrast, the larger number of improved Type 052D destroyers, with their total propulsion power increased to over 52 MW, can effectively handle such pure speed-based provocations. Even in high-temperature sea areas, an improved Type 052D retrofitted with the CGT-30M can sustain a stable speed of 29–30 knots over extended periods while utilizing only about 90% of the gas turbine's power, giving it stronger maneuverability than the older Type 052D variants.

Of course, the hull form design of the Type 052D is considered somewhat outdated by today's standards—although it has a high length-to-beam ratio coefficient, its high-speed performance is not significantly superior to that of European medium-sized destroyers. Even after retrofitting with the CGT-30M, it would still be difficult to push the actual maximum speed to 32–33 knots. The significance of retrofitting the CGT-30M lies in using the mature Type 052D platform to test the new generation of independently developed advanced marine gas turbines, accumulating valuable operational experience to fully prepare for future improvements and applications. Simultaneously, it provides the fleet with a batch of mature medium-sized combat vessels capable of high-speed maneuverability in major sea areas, thereby enhancing the fleet's ability to respond to various contemporary provocations and threats.

Constrained by the current propulsion-electrical system architecture of the Type 052D, retrofitting the CGT-30M cannot bring a crucial increase in electrical power generation capacity to the improved Type 052D; it can only enhance the maneuverability of this destroyer series. Nevertheless, this is a very valuable improvement. Increasing the electrical power generation capacity of the Type 052D series in the future is a relatively urgent and somewhat challenging issue, but it should not be the primary concern at present. Expediting the commissioning of the new generation of destroyers is the fundamental solution to updating and replacing the combat capabilities of medium-sized destroyers. Implementing the CGT-30M, as a key propulsion component for future new-generation vessels, on mature ships first helps accelerate the deployment of new-generation propulsion equipment/systems and enhances the comprehensive combat power of existing mature vessels. This is truly a multi-beneficial approach.

Comparison table between the power outputs and thermal efficiencies of CGT-25M, CGT-30M and LM2500+, made by SOYO:

Model	CGT-25M​	CGT-30M​	LM2500+​
Rated Max Power Output (ISO)	28.7 MW​	32-33.5 MW​	30.2 MW​
Rated Max Power Output (Naval GJB)	24.26 MW​	30 MW​	28.5 MW​
Rated Max Power Output (USN NSD)	20 MW​	27.5 MW​	26.63 MW​
Thermal Efficiency (ISO)	36%​	39.3%​	39%​
Power Output at 90% capacity (USN NSD)	18 MW​	24.75 MW​	24 MW​