DDG(X) - Arleigh Burke Replacement

[Forest Green]

Couldn't find a thread, I felt their ought to be one.

U.S. Navy’s Future Large Scale Combatant Force-Level Goals - Naval News

The U.S. Navy’s Large Surface Combatant force consists of three destroyers: Arleigh Burke-class , DDG 1000 Zumwalt and the upcoming DDG(X).

www.navalnews.com

• 5-inch (127-mm)/62 cal Mk. 45 Mod. 4
• 4 × 32 Mark 41 Vertical Launching System (VLS) cells (swappable with larger VLS systems)
• Two 21-cell Rolling Airframe Missile launchers
• Two Mark 32 Surface Vessel Torpedo Tubes
• 150/600kW lasers (possible upgrade)

View: https://www.youtube.com/watch?v=IIfiT7koThc

EPIRUS
A rendering of a ship-based high-power microwave system designed by the Epirus company.

 

[PMN1]

Couldn't find a thread, I felt their ought to be one.

U.S. Navy’s Future Large Scale Combatant Force-Level Goals - Naval News

The U.S. Navy’s Large Surface Combatant force consists of three destroyers: Arleigh Burke-class , DDG 1000 Zumwalt and the upcoming DDG(X).

www.navalnews.com

• 5-inch (127-mm)/62 cal Mk. 45 Mod. 4
• 4 × 32 Mark 41 Vertical Launching System (VLS) cells (swappable with larger VLS systems)
• Two 21-cell Rolling Airframe Missile launchers
• Two Mark 32 Surface Vessel Torpedo Tubes
• 150/600kW lasers (possible upgrade)

View attachment 676180

View attachment 676181

View: https://www.youtube.com/watch?v=IIfiT7koThc



View attachment 676182

View attachment 676183

EPIRUS
A rendering of a ship-based high-power microwave system designed by the Epirus company.

Where are the 4 x 32 cell VLS

 

[Forest Green]

Where are the 4 x 32 cell VLS

2 x 32cells in front of main tower, 2x32cells behind main tower but in front of enclosed hangar. Each of the little rectangles is 8 so each row is 32.

 

[TomS]

Where are the 4 x 32 cell VLS

Don't assume that any of the models we've seen so far are completely indicative of a final design. The illustrative concept design that has been shown does seem to show a 64-cell block forward and another, probably similar block amidships, between the stacks (which could be replaced by the Destroyer Payload Modules).

 

[Forest Green]

Looks like there's an option to swap a block of 32 cells for 12 large missile cells. Maybe for LRHW, maybe even GBI, who knows.

 

[TomS]

Had not seen that Phalanx-derived HPM concept before. Very interesting indeed. Interesting to see basically four Phalanx-scale point defense systems possible on this conept -- 2 x Mk 49 RAM, 1 x HPM, and 1 x 150 kW LaWS.

 

[Forest Green]

Had not seen that Phalanx-derived HPM concept before. Very interesting indeed. Interesting to see basically four Phalanx-scale point defense systems possible on this conept -- 2 x Mk 49 RAM, 1 x HPM, and 1 x 150 kW LaWS.

I'm not actually sure where that's located, it was mentioned in this article.

This Is What We Now Know About The Navy’s Future DDG(X) Destroyer

The Navy hopes to combine existing systems with a new hull form that will be able to accommodate significant upgrades.

www.thedrive.com

 

[Tool_Shed_Toker]

I like it, on paper at least. I wouldn't be against the addition of a few NSM/harpoon launchers to keep the VLS available for other munitions. Curious what the aviation facilities entail, Id imagine there's some hanger room for drones in addition to a Seahawk.

 

[Forest Green]

I like it, on paper at least. I wouldn't be against the addition of a few NSM/harpoon launchers to keep the VLS available for other munitions. Curious what the aviation facilities entail, Id imagine there's some hanger room for drones in addition to a Seahawk.

It says an increased size hangar, so bigger than Ticonderoga and Arleigh Burke Class. There doesn't appear to be any dedicated AShM launchers but it does have 6 more VLS than a Ticonderoga and 32 more than an Arleigh Burke.

 

[TomS]

Had not seen that Phalanx-derived HPM concept before. Very interesting indeed. Interesting to see basically four Phalanx-scale point defense systems possible on this conept -- 2 x Mk 49 RAM, 1 x HPM, and 1 x 150 kW LaWS.

I'm not actually sure where that's located, it was mentioned in this article.

This Is What We Now Know About The Navy’s Future DDG(X) Destroyer

The Navy hopes to combine existing systems with a new hull form that will be able to accommodate significant upgrades.

www.thedrive.com

Yeah, I was remembering another concept (not DDX) that shows both laser and HPM. Oh, right, the German Meko A300. https://www.navalnews.com/naval-news/2021/10/tkms-powerful-meko-a300-frigate/

It says an increased size hangar, so bigger than Ticonderoga and Arleigh Burke Class. There doesn't appear to be any dedicated AShM launchers but it does have 6 more VLS than a Ticonderoga and 32 more than an Arleigh Burke.

The question is whether that means increased size compared to the two very cramped spaces in the DDGs. Each one is barely big enough for a Seahawk. I suspect that's future-proofing for a FVL-Maritime that could be bigger than an H-60 and/or a UAV system bigger than Firescout.

As for ASCM, I suspect the omission of dedicated launchers is intentional. The FFGs are loaded up with deck-launched ASCMs (16 NSM) and are more able to be pushed forward to engage at intermediate range. DDG(X) has to sit back more for the area defense mission. So it's more likely to use Tomahawk Blk Va (MST), SM-6 Blk IB, or whatever future weapons fall out of NGLAW (if any). And those all fit in the VLS.

 

[Rakoval501]

I found some DDG(X) variant that bears the name of "Fuel-Efficient Destroyer", fitted with 5 Wartsila diesels as an only propulsion:

https://2n.mit.edu/sites/default/files/documents/DDGX-14.pdf

 

[TomS]

I found some DDG(X) variant that bears the name of "Fuel-Efficient Destroyer", fitted with 5 Wartsila diesels as an only propulsion:

https://2n.mit.edu/sites/default/files/documents/DDGX-14.pdf

This is a 2014 student design exercise from an MIT naval architecture course. There quite a few other interesting projects there, but none are official.

Projects | Naval Construction and Engineering @ MIT

2n.mit.edu

 

[Cordy]

I found some DDG(X) variant that bears the name of "Fuel-Efficient Destroyer", fitted with 5 Wartsila diesels as an only propulsion:

https://2n.mit.edu/sites/default/files/documents/DDGX-14.pdf

This is a 2014 student design exercise from an MIT naval architecture course. There quite a few other interesting projects there, but none are official.

Projects | Naval Construction and Engineering @ MIT

2n.mit.edu

Reading the report was not surprised by the claim that diesels give up to 28% saving in fuel, assuming comparing to the Burkes with their all GT propulsion, GT's are gas guzzlers unless operating at 90%+ rpm, what did surprise me was the claim of 14% reduction in hull drag using Design of Experiments (DOE).

 

[TomS]

what did surprise me was the claim of 14% reduction in hull drag using Design of Experiments (DOE).

The DDG-51 hull has never been exceptionally low-drag. There are lots of efficiencies to be had.

I feel like the elimination of the bow sonar dome in favor of a smaller bulbous bow probably contributed to the drag reduction.

 

[MihoshiK]

what did surprise me was the claim of 14% reduction in hull drag using Design of Experiments (DOE).

The DDG-51 hull has never been exceptionally low-drag. There are lots of efficiencies to be had.

I feel like the elimination of the bow sonar dome in favor of a smaller bulbous bow probably contributed to the drag reduction.

I know for sure that there was a study about adding a bulbous bow to the Burke platform (while keeping the sonar), and that the fuel savings were considerable, but nothing was ever done with that.

Don't have access to that pc right now though.

 

[TomS]

what did surprise me was the claim of 14% reduction in hull drag using Design of Experiments (DOE).

The DDG-51 hull has never been exceptionally low-drag. There are lots of efficiencies to be had.

I feel like the elimination of the bow sonar dome in favor of a smaller bulbous bow probably contributed to the drag reduction.

I know for sure that there was a study about adding a bulbous bow to the Burke platform (while keeping the sonar), and that the fuel savings were considerable, but nothing was ever done with that.

Don't have access to that pc right now though.

Here's one version (in a tow tank model):




Also, a technical article on various hydrodynamic improvements to the AB design. A lot of them are basically lengthening the effective hull form with flaps, wedges, or bulbs.

 

[MadRat]

There has been considerable work on getting away from conventional single hulls. Frigates make up considerable amount of your modern fleet so efficiency is important. If they went with a hybrid trimaran with thinner profiles they could cut drag and increase stability while adding deck space. You can run your deepest missile cells into the central hull that carries the keel and main wing. Each outer hull on a trimaran could sport lighter missiles and other weapons with less depth, like the CIWS.

Deck space could contain blowout panels for storing spare shells and missiles, so that the ship could survive hits on magazine space. You would also want deck space optimized for drones and helicopters. Instead of one rear hangar door, you could have one for each deck side. This would allow for more utility out of available deck space. Flexible solar panels, which are very portable and replaceable, could cover as much deck as possible to augment generators.

The central trimiran hull would support your sonar. Bonus if the sonar can be lifted out of the water to be serviced while underway. (Engineers could surely figure that out.) Each outer hull could support a towed array, so there's always a spate. Use bow and stern planes to keep the ship on plane in cruise as well as on sprints. The outer hulls could be less draft to allow for emergency turning with roll and yaw induced by the ships FBW controls. Computerized navigation allows you to use shorter hull lengths, which too much length would limit manueverability. Multiple hulls is a smoother ride for the occupants in most cases. Of course your crew would have to operate in that mindset of keeping everything tied down on the deck for emergency manuevers, including themselves. Long trips with a stable deck might encourage them to forget that the whole deck could roll 30 degrees in mere seconds.

 

[Cordy]

Stern Flaps/Hull Vanes reducing hull drag

Naval Surface Warfare Center Carderock Division in 2000 did full scale trials on DDG-61/Burke USS Ramage with a Stern Flap 13° installed behind transom wedge.

"The stern flap evaluation trials on RAMAGE indicated that the stern flap reduced the ship power-at-speed by 5.6% to 15.4%. It appeared to have virtually no negative impact on ship operations on a speed/power basis. The stern flap also increased the top speed of the RAMAGE by 0.9 knots. However, in order to attain full propulsion plant power, and achieve the maximum 31.8 speed with flap installed, it was necessary to increase the propeller pitch by approximately 5% over design. The stern flap data also shows a substantial power reduction of more than 14,000 hp (14.1%), at the 30.9 knot maximum ship speed achieved by the baseline ship. Trials indicate that the installation of a stern flap, on a DDG 51 Class Flight I/II destroyer, will result in a net annual fuel savings of 4726 barrels (7.5% reduction) per ship. The annual fuel cost savings will be $195,000 per ship"

https://apps.dtic.mil/dtic/tr/fulltext/u2/a507858.pdf

More recently in 2018 a French patrol vessel was fitted with a Hull Vane, “comparison with the benchmark sea trials – conducted in January in exactly the same conditions – by CMN’s sea trial team showed a reduction in fuel consumption of 18% at 12 knots, 27% at 15 knots and 22% at 20 knots. The top speed increased from 19.7 knots to 21 knots.”

https://chuckhillscgblog.net/2020/1...ne-hydrofoil-on-hnlms-zeeland-opv-naval-news/

View: https://www.youtube.com/watch?v=4Npm5FXnOLE&ab_channel=HullVanebv

 

[sferrin]

Cha-ching.

 

[TomS]

There has been considerable work on getting away from conventional single hulls. Frigates make up considerable amount of your modern fleet so efficiency is important. If they went with a hybrid trimaran with thinner profiles they could cut drag and increase stability while adding deck space. You can run your deepest missile cells into the central hull that carries the keel and main wing. Each outer hull on a trimaran could sport lighter missiles and other weapons with less depth, like the CIWS.

Deck space could contain blowout panels for storing spare shells and missiles, so that the ship could survive hits on magazine space. You would also want deck space optimized for drones and helicopters. Instead of one rear hangar door, you could have one for each deck side. This would allow for more utility out of available deck space. Flexible solar panels, which are very portable and replaceable, could cover as much deck as possible to augment generators.

The central trimiran hull would support your sonar. Bonus if the sonar can be lifted out of the water to be serviced while underway. (Engineers could surely figure that out.) Each outer hull could support a towed array, so there's always a spate. Use bow and stern planes to keep the ship on plane in cruise as well as on sprints. The outer hulls could be less draft to allow for emergency turning with roll and yaw induced by the ships FBW controls. Computerized navigation allows you to use shorter hull lengths, which too much length would limit manueverability. Multiple hulls is a smoother ride for the occupants in most cases. Of course your crew would have to operate in that mindset of keeping everything tied down on the deck for emergency manuevers, including themselves. Long trips with a stable deck might encourage them to forget that the whole deck could roll 30 degrees in mere seconds.

Trimarans have been a topic of interest for quite a while (the Independence class LCS being the most obvious example);. But they don't seem to scale well. Or, rather, it seems that the benefits decrease with size, so larger ships don't gain enough to justify the more complex hull structure and cost of construction. Likewise, when lower service speeds are acceptable, the powering advantages of the trimaran form fade out.

Trimarans in general lack hull volume compared to monohulls. They are essentially very slender monohulls for powering efficiency with sidehulls added for stability. However, the optimal hydrodynamic solutions for tend to put very little volume in the sidehulls (~5% is typical, IIRC) so they really aren't usable for much in the way of equipment. Likewise, the bow of a very slender hull isn't usually very efficient for equipment.

Trimarans do increase deck area, which can be of value. But it's generally not the biggest limiting factor for aircraft operations -- hangar volume if much more limiting. You can buy hangar volume with a large superstructure, but that weight has to be supported somehow.

One example: in the late 1990s, NAVSEA did a Spring Style on frigate and corvette concepts. They designed a baseline monohull frigate using a fairly slender DD-21 style hullform (LBP:B of 8.95:1) that displaced just a shade under 5000 tons. A comparable trimaran with the same armament and sensors was almost 20% longer and displaced about 14% more (just over 5600 tons). It also had a draft a full 1.4 meters deeper than the monohull. The trimaran required a bit less propulsion power for the same speed but would have likely cost more to build.

 

[MadRat]

Trimarans can be done many ways. Your description of the case study certainly sounds like a dead end as a frigate.

There's a lot of hulls to choose from. You've got displacement hulls, planing hulls, swaths, and designs somewhere in between. Displacement hulls are probably ideal for frigates for stability and efficiency, plus they also can operate well under electrical propulsion. Planing hulls literally are for speed but require lots of excess power, which doesn't really fit the role of s frigate. Swaths operate on Archimedes principle, generating lift by water displacement. An ideal swath is tubular and is generally low drag by always staying wet. Break the water surface with a swath and generally it generates excessive wave breaks, which would be rough and inefficient at the same time. Use it correctly in a wet profile and its ideal in rough seas. No matter the guesses we make on the periphery, we know for a fact the centerline hull will be a displacement hull.

We have other things to consider, too. What kind of bow? Go with the conventional bow, an inverted bow, the axe-bow, the scow, the Pantocarene, or perhaps an X-bow? I'm not a fan of inverted bows as they can nose-dive under water. The X-bow is literally a stretched axe box with a curved front. The Pantocarene is a combination of inverted and conventional, with a sharp inverted beak. The axebow doesn't nose-up or down like the inverted or conventional bows. The scow is popular for sailing, but would be a radical departure from conventional thinking. Scows can be used in planing hulls but are usually associated with a displacement hull. The scow, like a Pantocarene, generally pierces the wave without pitching.

I'd want to concentrate all the deck protrusions in the bow. Keep the foredeck in a relatively high elevation but leave midship and transom lower relative to the water. A tall bow should help the rest of the deck stay dry. It also gives a good long-range view for radar in all directions. I'd want swath or axe bow style outer hulls, even if the space was marginal. The outer hulls add row stability and improve straight-line course holding. Is there a way to add deck space? Of course. Will it cost a lot? Only if done exotically. I'd want a deck that spanned both outer hulls, and it be at least one if not two decks underneath. (I've seen 150' exotic fishing yaughts sport 6-8 decks, so its not at all a stretch of the imagination.) Inner walls would give support to hold up the top deck and to support the floor. The floor is essentually an extension of the hull, so it would be engineered for water swells striking it. This really isn't drastically different than LCS general idea. Only it could be less aluminum and focus more ultimate deck space on top of the ship. And because we're a displacement hull not built for speed, weight is less of an issue. We want range and at a decent pace. I would also focus on augmenting power with solar to extend range and add pace. The general shape would be perhaps like a low-sitting water bird, of course without the bill.

 

[TomS]

I don't feel like tackling this whole thing, but one example of a problem area:

I'd want swath or axe bow style outer hulls

These two are so different that they don't seem like solutions to the same problem set. Axe bows are meant to reduce pitch motions; in a trimaran, it's the main hull that is going to be the principal pitch generator, since it has most of the volume. The sidehulls are just following along, and you don't want them pitching too much differently from the main hull, because that creates torque on the cross-deck structure.

SWATH sidehulls on a trimaran is a terrible idea. Conventional sidehulls provide stability because their immersion and thus buoyancy rise as the ship rolls. SWATH hulls are the exact opposite -- assuming the SWATH pod is fully immersed, the struts holding it to the cross structure provide very little change in buoyancy in response to changes in immersion. So SWATH fails to serve the main purpose of a trimaran sidehull. People have tinkered with SWATH-like trimarans, but they are almost always the other way around -- a single submerged bulb center hull and two small conventional sidehulls to help keep the main hull upright (SWASH for single-hull rather than twin hull). But this shape is very sensitive to displacement changes, so you have to ballast for fuel consumed and so forth.


In any event, we can be very sure that DDG(X) will be some variation on a conventional displacement monohull, based on the Navy's public statements, presentations, and preferences. the LCS trimaran only got a look becuase of the extreme speed requirement, which isn't in DDG(X).

The only question will be the extent to which it follows the design of DDG-1000 in terms of tumblehome and bow shape (the "Platypus" hullform). It seems clear \that the Navy is focused on a raked stem, maybe even a clipper bow, apparently for artic seakeeping? The hull and superstructure aft of that may be more Zumwalt-like; a lot of published information is showing a hull with tumblehome down to the waterline aft, which is useful for RCS reduction. The superstructure is anyone's guess. The big Zumwalt-type monolithic deckhouse (below) has RCS advantages but limits arrangeable deck area, especially for trainable weapons like guns, RAM, and lasers. A more traditional superstructure (seen in earlier posts) is easier to place all those systems, but adds lots of potential radar corners unless very carefully designed.

(Note on this image: I'm not 100% sure it's actually associated with DDG(X). It's possible it was an analysis of alternatives for DD-21/DD(X) that they have dug up and used in modern presentations. If anyone knows the provenance better, I'd be very curious.)

 

[sferrin]

That orange model sortof looks like this from the DD-21 days:

 

[sferrin]

I don't feel like tackling this whole thing, but one example of a problem area:

I'd want swath or axe bow style outer hulls

(Note on this image: I'm not 100% sure it's actually associated with DDG(X). It's possible it was an analysis of alternatives for DD-21/DD(X) that they have dug up and used in modern presentations. If anyone knows the provenance better, I'd be very curious.)

View attachment 678082

As narrow as that front end is I'd think it would almost demand the use of the MK57 VLS.

 

[TomS]

As narrow as that front end is I'd think it would almost demand the use of the MK57 VLS.

I don't think so. It's no worse than DDG-1000, and without the AGS in that ship there would be tons of volume forward for traditional VLS.

 

[sferrin]

As narrow as that front end is I'd think it would almost demand the use of the MK57 VLS.

I don't think so. It's no worse than DDG-1000, and without the AGS in that ship there would be tons of volume forward for traditional VLS.

I'd think you'd still want at least one Mk45 up front.

 

[Moose]

I don't feel like tackling this whole thing, but one example of a problem area:

I'd want swath or axe bow style outer hulls

These two are so different that they don't seem like solutions to the same problem set. Axe bows are meant to reduce pitch motions; in a trimaran, it's the main hull that is going to be the principal pitch generator, since it has most of the volume. The sidehulls are just following along, and you don't want them pitching too much differently from the main hull, because that creates torque on the cross-deck structure.

SWATH sidehulls on a trimaran is a terrible idea. Conventional sidehulls provide stability because their immersion and thus buoyancy rise as the ship rolls. SWATH hulls are the exact opposite -- assuming the SWATH pod is fully immersed, the struts holding it to the cross structure provide very little change in buoyancy in response to changes in immersion. So SWATH fails to serve the main purpose of a trimaran sidehull. People have tinkered with SWATH-like trimarans, but they are almost always the other way around -- a single submerged bulb center hull and two small conventional sidehulls to help keep the main hull upright (SWASH for single-hull rather than twin hull). But this shape is very sensitive to displacement changes, so you have to ballast for fuel consumed and so forth.
View attachment 678081

In any event, we can be very sure that DDG(X) will be some variation on a conventional displacement monohull, based on the Navy's public statements, presentations, and preferences. the LCS trimaran only got a look becuase of the extreme speed requirement, which isn't in DDG(X).

The only question will be the extent to which it follows the design of DDG-1000 in terms of tumblehome and bow shape (the "Platypus" hullform). It seems clear \that the Navy is focused on a raked stem, maybe even a clipper bow, apparently for artic seakeeping? The hull and superstructure aft of that may be more Zumwalt-like; a lot of published information is showing a hull with tumblehome down to the waterline aft, which is useful for RCS reduction. The superstructure is anyone's guess. The big Zumwalt-type monolithic deckhouse (below) has RCS advantages but limits arrangeable deck area, especially for trainable weapons like guns, RAM, and lasers. A more traditional superstructure (seen in earlier posts) is easier to place all those systems, but adds lots of potential radar corners unless very carefully designed.

(Note on this image: I'm not 100% sure it's actually associated with DDG(X). It's possible it was an analysis of alternatives for DD-21/DD(X) that they have dug up and used in modern presentations. If anyone knows the provenance better, I'd be very curious.)

View attachment 678082

That model in the upper right corner may be an FFG(X) model, which would make this photo reasonably recent.

 

[TomS]

As narrow as that front end is I'd think it would almost demand the use of the MK57 VLS.

I don't think so. It's no worse than DDG-1000, and without the AGS in that ship there would be tons of volume forward for traditional VLS.

I'd think you'd still want at least one Mk45 up front.

Each AGS is roughly a 64-cell Mk 41 VLS block (maybe more). Plenty of room for 64 cells and and a Mk 45, even if this ship is smaller than DDG-1000 (which it might be). Then more VLS elsewhere (alongside the flight deck, in a block aft, etc. The challenge in this config is where the RAM and MCGS go. (ExLS would be nice to hide both RAM and Nukla, but it's another project that isn't already done, which is not how DDG(X) is rolling. Plus, it doesn't leave the kind of space reservations you'd want for a laser instead of RAM.)

I do not think the hydrodynamic model is likely to be fully representative of topside arrangements, just a general idea to see how it all behaves in extreme sea conditions.

That model in the upper right corner may be an FFG(X) model, which would make this photo reasonably recent.

Good eye. Very likely it is FFG-61 due to the lack of a sonar dome.

 

[Hydroman]

Hopefully, a DDG-X replacement will not have a periphery launch system like DDG-1000, seems very exposed and vulnerable. It needs to maintain forward amidship and aft/central amidship VLS batteries. Got to tour CGN-9 when I was in the USN in theearly 80's, even though had older dual launch rails, magazine capacity and auto-loading was impressive, got to witness functional checkout of the system. China really arming up their Type 055 ships?

 

[TomS]

Hopefully, a DDG-X replacement will not have a periphery launch system like DDG-1000, seems very exposed and vulnerable. It needs to maintain forward amidship and aft/central amidship VLS batteries. Got to tour CGN-9 when I was in the USN in theearly 80's, even though had older dual launch rails, magazine capacity and auto-loading was impressive, got to witness functional checkout of the system. China really arming up their Type 055 ships?

In reality, the peripheral system is less vulnerable. PVLS is spaced armor, basically. Each block of four Mk57 cells is in a separate compartment with heavy bulkheads isolating it from the next block and inner hull. Insensitive munitions make a sympathetic detonation unlikely and the blocks also vent outward rather than toward the interior of the ship.

That said, it's clear that DDG(X) anticipates at least some central VLS blocks. They talk about being able to replace a 32-cell module with larger VLS tubes for example.