CVX design – Seoul Modern naval warfare

-Raghu Varier

Months back we had covered two articles on modern naval warfare. One was regarding what constitutes it such as USVs (Unmanned Surface Vehicles), UAVs (unmanned aerial vehicles) etc and the other was on how these units will work in tandem controlled by a mothership. Additionally we had also covered the LPX-2 design for South Korea. There we remarked that the conceptual design stage was completed. A few days ago, during MADEX2021 (International Maritime Defense Industry Exhibition) , Hyundai Heavy Industries surprised everyone with a very modern designs for CVX which had many improved design features and adopted modern naval warfare strategies. DSME (Daewoo Shipbuilding and Marine Engineering) showcased their refined design today. The DSME design is pretty much like its earlier unveiled concept however the HHI design is very different. Let us take a look at both of them.

DSME CVX design

The old initial conceptual design for LPX-2 was by Daewoo Shipbuilding and Marine Engineering as shown below and this was covered in our previous article.

Previous Design by Daewoo Shipbuilding and Engineering Limited

There isn’t any major design changes in DSME designs apart from the incorporation of modern naval warfare strategies. The new design of DSME has a loaded displacement of 38000 tons and can sail at a maximum speed of 27 knots. It has a crew complement of 1400 sailors and features a flat deck. It is said from DSME that it is designed for upto 45000 tons. This design can accomodate 12 F-35 Bs in its hanger and 16 F-35 Bs on its flight deck. This CVX design features 2 CIWS (Close-in Weapon System) one at stern and one at bow. The KVLS (Korean Vertical Launching System) will be located at the stern behind the second island. British company Babcock and Italian design firm Fincantieri provided initial design assistance with regard to connecting the onboard aircrafts with the mothership.

Fincantieri to support Daewoo in the design of the New Korean Aircraft  Carriers - EDR Magazine
New DSME CVX design

As per DSME this design can load any helicopter and it is said to be meeting the operational requirements of the ROK (Republic of Korea) Navy. The DSME design features anti-drone defense systems and 9 spots for helicopters. The location of AESA (Active Electronically Scanned Array) radar is retained at the upper level of the islands as per previous design.

Flight hanger in DSME CVX

Hyundai Heavy Industries (HHI) CVX Design

The ‘wow’ factor during MADEX2021 was the HHI CVX design. The displacement of the vessel is kept at 30000 tons which is lower than DSME’s new design. The vessel has a twin island arrangement with one island handling overall operations and the other handling flight control duties. This vessel will be able to carry 16 to 20 F-35 B fighters on its deck as opposed to 16 on DSME’s design. If no jets, it can carry upto 30 helicopters. It can carry only 6 helicopters on the deck as compared to DSME’s 9. The previous length was 265 m but now it is 270 m, which is not much change as compared to other vessel particulars.

Design particulars

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New Design by Hyundai Heavy Industries during MADEX2021
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The first basic change done in the design for HHI CVX is the width. The previous design had a width of 43 m but the current design has a width of 60 m. That is like almost a 50% increase. This means the flight deck area has increased than previous. As per Naval news, the representative concerned suggested that the lower part of the hull has been redesigned and currently has a less thicker hull than previous design. Also lowering of displacement has resulted in a decrease in internal space.

The engineering reasoning behind increasing the length is that there will be a decrease in resistance due to increased L/B. This will help the vessel achieve somewhat higher speed with the same propulsion planned than initally conceived. The engineering reasoning behind increasing the beam is that you get better stability due to increase in the righting lever arm. Since displacement is lower than DSME design, the increase in length and beam mean a decrease in design draught which means a higher B/T. This means power requirements must have been brought down which is why the speed that can be achieved has gone up.

Change in bow design

What’s very interesting is the change in bow design. The new design by HHI doesn’t feature a bulbous bow as compared to previous design. Instead it has adopted a unique bow design that incorporates what seems like a design that can help spill the waves away from the vessel thereby reducing the wave-making resistance component of the vessel. Also there are 2 bow thrusters as opposed to one before. This perhaps is to provide for desired maneuverability that actually deterioates when the width or beam is increased.

Difference in DSME and HHI design

Apart from this the new design features a modular ski-jump as opposed to none in the previous design. This is because use of a ski-jump will allow F-35 Bs to take off more easily in full-loaded condition. As per HHI representative, use of ski-jump allows sortie rates to be less influenced by other variables such as wind, humidity etc. This will enable higher sortie rates. The modularity of the ski-jump with its long flight deck means that the carrier can be easily converted for STOBAR (Short Take Off But Arrested Recovery) operations. However conversion to CATOBAR (Catapult Assisted Take Off Barrier Arrested Recovery) operations seem difficult because of the high power requirement. This means that the entire propulsion system will have to be changed to facilitate for CATOBAR conversion. Daewoo representatives however have apprehensions on whether the ski-jump design is optimal for high sortie rates. This is because use of ski-jump will only mean F-35 Bs using less of the runway which does not necessarily mean higher sortie rates and hence there is a reasearch in progress to address this issue.

Change in island design

The twin islands have their designs improved. They now possess an X-shaped design. The advantage is that it provides improved stealth capabilities by reducing overall radar cross section. Another advantage is that the ship’s AESA radar is installed at the lower level of the island. This is done so that the radar will not be affected by flight operations being carried out. Overall this frees up sufficient space at the top levels of the island to install many other sensors. The X-shape of twin island means that the upper deck is used for flight control operations which provide great visibility of the flight deck. However such low location might probably hinder detection of inbound hostile aircrafts.

Lower level for AESA radar and X-shape island design for better flight control operations

CVX as a mothership for modern naval warfare

Modern naval warfare – CVX as a mothership

What is more interesting is the adoption of modern naval warfare in the CVX design process. Adequate focus has been laid on the use of unmanned systems right at the conceptual design stage. There is a special flight deck at the stern for the operation of UAVs that take-off vertically. Right beside the UAV flight deck, there are 16 KVLS cells. In order to facilitate operation of UUVs and USVs, there is a mini-well deck.

Verdict

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The adoption of modularity, scalability and incorporation of modern naval warfare functionality right at the design stage will help the Korean Navy make the necessary improvements easily at a later stage. This includes the conversion of the the carrier to a STOBAR type in the future. The DSME design focuses more on the anti-drone warfare whereas the HHI design focuses more on use of UXVs (Unmanned X Vehicles). The DSME design is a flat top one whereas the HHI design features a ski-jump which can be removed to make a flat top carrier.

The HHI CVX design has dedicated decks for operation of UAVs, UUVs and USVs which indicates the role of CVX as a mothership and thereby extending the range of operations that can be conducted. Adoption of X-shaped twin island will result in much lower RCS and the low level placement of AESA enables continued operability unhindered by flight operations. Although there are concerns about long range detection. That being said both the designs are equally good and it is upto the ROK Navy now to chose them based on their doctrine.

CVX Design adoption for INS Vishal

The Indian Navy has been insisting on third aircraft carrier INS Vishal but given the budget limitations, it has had to prioritize the SSNs. This actually can be a boon in a way for the Indian Navy as they get considerable time to conceptualise and finalise the design for INS Vishal as an aircraft carrier adopting modern naval warfare. Given that Indian Navy intends to expand its operations further into South China Sea and West Africa, they must definitely explore such designs as they provide considerable benefits with regard to assault operations and power projection. Apart from that it also provides Indian Navy a flexibility to make incremental improvements as and when technologies get developed.

India must utilize this time to explore India-South Korea collaboration in this domain. It is well known that the South Korean shipbuilding industry is unique and considered one of the best in the world. Given that India and South Korea have traditional trade links, such a viable option is in line with India’s “Look East” aspect of foreign policy and will definitely provide India the asset for power projection in the Indo-Pacific.

Interested about ship stability concepts? Visit our technical articles on our tech website on ship stability.

By Alpha Defense

Alpha Defense initially a solo venture but now a defense group by people from various demographics of India covering defense news and updates. We believe in unbiased analysis of every subject in hand. Our mission is to provide simplfiied defense information to the public.

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