Chinese (conventional) Kirov here we come? 055 is already 13,000 tons, and seeing how usually warship classes gradually increase in size, it's not unreasonable to expect a 055 successor to be anywhere from 15,000 to even 20,000 tons.
Next Generation DDG and FFG thread (after 055, 052D, 054B)
- Thread starter ACuriousPLAFan
- Start date
055 only used four because China did not have any advanced turbines at the time of design so had to make due with 4 GT25000s. Now they have multiple high power turbines to choose from like QC500, which two of these could in theory easily power a 055 upgrade. 4 turbines and a whopping 10 diesel generator system for me either means a huge cruiser with extreme power demand or a carrier.
Also, 4 CGT40s along with associated diesel system could output at peak similar power as Type 003 according to SOYO's analysis which I've posted in the 004 thread. So definitely not underpowered for a carrier.
He specifically referenced the CG(X) program, so possibly he means PLAN will be pursuing a cruiser of similar design/purpose.
What kind of power is estimated from these setups? If a CGX equivalent, since nowadays railguns and DEWs are all the rage, extremely high power level will be needed to power those.
(Please note that all the power output values of gas turbine engines mentioned below are obtained at ISO conditions.)
For reference, the 055 DDGs (full-load displacement of ~13000 tons) are propelled by 4x CGT-25 marine gas turbine engines in COGAG configuration. Each CGT-25 engine has a power output of ~27 MW, meaning a combined power output of ~108 MW for propulsion.
In the meantime, as of today - China has successfully developed (or getting to the completion of developmental works) of more powerful marine gas turbine engines, namely the CGT-30, QC-400, CGT-40 and QC-500. There are also likely to be a CGT-50 and even a CGT-60, but due to the lack of more discernible information on these two marine gas turbine engines, they will be excluded from this discussion.
Comparing the propulsion configuration setting of the 055 DDGs with other settings using other marine gas turbine engines, assuming that all the gas turbine engines within their respective configuration settings are of the same model:
| Gas Turbine Engine Model | Individual Power Output | Number of Gas Turbine Engines | Combined Gas Turbine Engine Power Output |
| CGT-25 | ~27 MW | 4 | ~108 MW |
| CGT-30 | ~33 MW | 4 | ~132 MW |
| QC400 | ~40 MW | 4 | ~160 MW |
| CGT-40 | ~42 MW | 4 | ~168 MW |
| QC500 | ~50 MW | 4 | ~200 MW |
In addition to the marine gas turbine engines, there is also the stated 10x diesel-electric engines, which together with the gas turbine engines, form the IEPS that is said to be capable of powering CVs (per SOYO) or CGs (per Cute Orca).
And when combining the above gas 4x turbine engines with the following 10x diesel-electric engines in IEPS configuration settings:
| Gas Turbine Engine Model | Individual Diesel-Electric Engine Power Output | Number of Diesel-Electric Engines | Combined Diesel-Electric Engine Power Output | Combined IEPS Power Output |
| CGT-25 | ~3 MW to ~6 MW | 10 | ~30 MW to ~60 MW | ~138 MW to ~168 MW |
| CGT-30 | ~3 MW to ~6 MW | 10 | ~30 MW to ~60 MW | ~162 MW to ~192 MW |
| QC400 | ~3 MW to ~6 MW | 10 | ~30 MW to ~60 MW | ~190 MW to ~ 220 MW |
| CGT-40 | ~3 MW to ~6 MW | 10 | ~30 MW to ~60 MW | ~198 MW to ~228 MW |
| QC500 | ~3 MW to ~6 MW | 10 | ~30 MW to ~60 MW | ~230 MW to ~ 260 MW |
Summing up, excluding the CGT-25-based setting - I do believe that both proposals by SOYO (meant for a CV) and Cute Orca (meant for a potentially BMD-capable CG) do have their respective merits, judging by the immense power output values where the above IEPS configuration settings are able to exert.
However, it must be noted that the possibilities of the two pairs of gas turbine engines in the aforementioned IEPS configuration settings do not share the same power output should not be discarded (whereby one pair of gas turbine engines have higher/lower power output values than the other pair), for reasons such as (mainly) fuel-economy measures. With this in mind, the combined IEPS power outputs of such configuration settings would lie somewhere between the 4x CGT-25-based IEPS configuration setting and the 4x QC500-based IEPS configuration setting.
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You forget the lesson of Type-45 destroyer. Regardless IEPS or direct drive, 4 GT is better than 2 larger GT because GT only works efficiently at full power. Naval ships do NOT constantly run at top speed, 80% of their time runs at lower than half of total installed power. 2 larger GT running at lower rating would make the ship very fuel consuming, in a 4GT configuration only 2 GT are needed to run at full power. It is called power granularity. Also, having 2 GTs running all the time than 4GT running 2 in terms increase the chance of breakdown, that was what happened to Type-45.
For the detailed study of Type-45's fault and remedy read the Royal Navy's study papers.
and
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Ok, your right but you also forgot that you could simply run a single turbine at high capacity to get around half power with diesels which according to you is what ships run at 80 percent of the time. Single large turbine do in fact have better efficiency than smaller turbines running at similar load, CGT25 only have a maximum efficiency of 36 percent while even the CGT30 improves this to 39.3 percent with larger models like CGT40 reaching 40+ percent. So, with two turbines you lose some power granularity since you'll lose the efficiency peak at 1/4 turbine power but I'm not so sure if ships often need that power level since for anything like low level cruise etc they could run on pure diesel with a IEPS design.
Rumored 20,000-ton cruiser