BBG(X) - DISCUSSION ONLY

[Dilandu]

What I think there is harder and harder to stop this madness, because they explicit sad that the DDG(X) is history, this BBG(X) replace it. If the Congress or anything else sink this plan, then the US Navy remain without a modern LSC again. Which leave the Burke-class continuation the only short time option, again.

The Navy would likey already have a backup plan to "reluctantly agree for something smaller" - basically for CG(X), of 15-20 kilotons. Which would be exactly what they actually wanted; hull big enough to fit everything they desired for DDG(X), but with a large margin for future refits.

 

[Not James Stockdale]

@ Not James Stockdale: Interesting if they’re considering rail-gun for BMD - I thought rail gun was meant for anti-ship & other slower-moving/stationary point targets.

I’ve read elsewhere (too lazy research a source right now) that rail-gun physics is proving intractable…1) Hitting a fast target with a fast HVP has tremendously small margins for error and a kinetic miss at that range with the speed of ballistic re-entry gives little time/distance for reaction, 2) In order to defend against a BMD salvo, the ship would need dozens-to-hundreds of large-capacity individual quick-discharge capacitors/batteries and a way to rapidly recharge them - perhaps more than current IEP technology can provide, 3) Current “barrel”-wear reduces the number of shots fire-able per deployment to something less than a VLS magazine.

I suppose one question is whether the investment in advancing to the Nth level of precision & innovation to resolve the problems posed by physics is truly worth the future cost…and the wait.

https://www.navalnews.com/naval-new...-pitches-railgun-for-air-and-missile-defense/
General Atomics was at AUSA 25 pitching their railguns for Golden Dome and BMD of Guam (and with container-sized power banks).

1. As long as the HVP can survive travel through the lower atmosphere at hypersonic velocities, then the interception question is the same as with a BMD missile because both can be guided. Total flight time to 30 nm is unlikely to be more than 10 seconds.
2. If General Atomics thinks a 20' container can generate and/or store a reasonable amount of power for the 32 MJ railgun, then there shouldn't be any issues fitting a sufficient amount of that equipment into the bow of a battleship. I don't know what the potential firing cycle is like.
3. Do we have a better understanding of what is possible in terms of barrel life compared to when the program was canceled in 2021? It looks like the Japanese and the Chinese think that there is a route to a sufficiently reliable weapon, and I've heard plenty of people say that the barrel life problem is less severe now than it was in 2021.

All of this makes me guess that the caliber will be scaled down in the future though.

The 32 MJ prototype had a nominal caliber of 150 mm, which would probably allow it to share HVPs with 155 mm guns. The GA 10 MJ railgun is probably closer in size to the 5" Mark 45, and from the videos I've seen look like it fires the smaller 127 mm HVPs.

 

[Dragonlady]

The cost question is secondary, especially as the first ships of a Class are always very expensive due to having the program cost accounted for, but still, I doubt the ship as presented is the final form. I think a lot of things will be scaled back, it will ultimately still be an exceptionally large surface combatant but not as huge and expensive as the concept is now.

As to what it brings to the table that justifies it's existence, it will replace the aging AAW cruisers with a state of the art Platform that will still have a lot to give in terms of growth and energy surplus. And this is the only viable way forward, because the venerable ABs can't take anything anymore, they're maxed out, a hypothetical Flight IV would have to see some major changes, like stretching the hull for more space. And as DDG(X) evolved into BBG(X) the cutting edge sensor, modern power systems, missile heavy, flag facilities equipped, premier battlegroup surface combatant is preserved.

I’m not talking about the lead ship though. All estimates indicate the per-ship follow-on cost to be at least $10 billion, which is absurd for anything that’s not a nuclear-powered supercarrier. Unit cost needs to come down at least 50% before this ship even starts making sense.

Why not brush off the BMD San Antonio concept? It has plenty of SWaP & growth room, and replacing the diesels with turbines should boost speed to ~30 knots. It may not be “sexy”, but it’s way more practical than this vanity project.

 

[Sferrin]

I’m not talking about the lead ship though. All estimates indicate the per-ship follow-on cost to be at least $10 billion, which is absurd for anything that’s not a nuclear-powered supercarrier. Unit cost needs to come down at least 50% before this ship even starts making sense.

Did the estimators describe HOW they arrived at $10 billion when virtually nothing is known about it?

 

[Not James Stockdale]

This is what the 01 Jan CRS report said: (https://news.usni.org/2026/01/01/report-to-congress-on-bbgx-battleship-program)

The BBG(X)’s potential procurement cost is uncertain. For ships of a given type (such as surface combatants),procurement cost can be roughly proportional to ship displacement. On that basis, a BBG(X) might have a procurement cost more than 3.6 times that of a DDG-51. DDG-51s currently cost about $2.7 billion each when they are procured at a rate of two per year, and something more than that when they are procured at a rate of one per year. This suggests a recurring unit procurement cost for the BBG(X) design of roughly $10 billion. The first BBG(X) might cost closer to $15 billion, because its procurement cost (following Navy budgeting practices) would incorporate detailed design costs for the class that could amount to a few billion additional dollars.

Obviously cost per ton is going to produce an inflated figure when a DDG-51 costs more per ton than an aircraft carrier.

My understanding is that the HM&E make up somewhere between 1/3 and 1/2 of the cost of a DDG-51 with combat systems making up the rest. I don't know if Flight III DDGs cost significantly more, and the BBG(X) is basically Flight III combat systems like the DDG(X) + the railgun + CPS tubes. My initial SWAG when I first heard about the BBG(X) announcement was $2 billion for combat systems and $4 billion for the hull. The hull might cost about 4x as much as a DDG-51, which is 1/4 the size, or about as much as the inflation-adjusted cost of an America-class LHA, which is the same size.

 

[cccgong]

Given the fact that the railgun is specifically stated to use HVPs, the primary role is probably terminal ballistic missile defense. The 32 MJ railgun was a muzzle velocity of roughly 2.5 kps with a 40 lbs projectile, and the HVP weighs 44 lbs. The performance of the HVPs out of the railgun would probably give a protected area similar to PAC-3 or maybe PAC-3 MSE (20 - 30 mile footprint), if the HVPs can eventually work in that role. Even if a BMD HVP costs $1 million compared to a $100k anti-missile HVP, that's 1/4 the cost of a PAC-3 MSE and a ship this big could easily carry 1,000 HVPs without touching the VLS. This is the same thing that the AGS tried to do with the Zumwalts (store 500+ PGMs outside the VLS) and there was little technically wrong with the AGS once development was complete.

The 5" guns are probably also there primarily for defense against anti-ship missiles. The HVP has already demonstrated effectiveness against subsonic sea skimmers and supersonic sea skimming targets are probably within the realm of possibility for additional development. Given the ballistic range of HVPs out of the 5" gun, I would expect a useful range comparable to ESSMs, and the guns with HVPs would again be cheaper than missiles and would not take up VLS cells. In both cases, even if the HVPs are less accurate than missiles, salvo and magazine sizes could easily make up the difference unless there was an enormous performance gap.

Do you have any additional info on the HVP performances missiles? Very curious to see what the performance is like. I’d also expect a 25-40mi range vs subsonic targets.

https://www.navalnews.com/naval-new...-pitches-railgun-for-air-and-missile-defense/
General Atomics was at AUSA 25 pitching their railguns for Golden Dome and BMD of Guam (and with container-sized power banks).

1. As long as the HVP can survive travel through the lower atmosphere at hypersonic velocities, then the interception question is the same as with a BMD missile because both can be guided. Total flight time to 30 nm is unlikely to be more than 10 seconds.
2. If General Atomics thinks a 20' container can generate and/or store a reasonable amount of power for the 32 MJ railgun, then there shouldn't be any issues fitting a sufficient amount of that equipment into the bow of a battleship. I don't know what the potential firing cycle is like.
3. Do we have a better understanding of what is possible in terms of barrel life compared to when the program was canceled in 2021? It looks like the Japanese and the Chinese think that there is a route to a sufficiently reliable weapon, and I've heard plenty of people say that the barrel life problem is less severe now than it was in 2021.


The 32 MJ prototype had a nominal caliber of 150 mm, which would probably allow it to share HVPs with 155 mm guns. The GA 10 MJ railgun is probably closer in size to the 5" Mark 45, and from the videos I've seen look like it fires the smaller 127 mm HVPs.

2) I don’t think you’ll get any reasonable rate of fire with that, for missile defense applications. For striker that’s more acceptable. Also for ICBM defense as the RVs are much more expensive, as they have nukes on board

3) I wouldn’t expect any improvements to rail life without either lower energies, a larger system, or an architecture change. The Japanese system is much much smaller, to the point that it likely has a different barrel life. As it is, I don’t think the Japanese system as much if any military use. As it fires unguided APFSDS.

You won’t be able to reuse, the HVP between standard and railguns due to shielding and different sabot requirements on the latter.

 

[Firefinder]

You won’t be able to reuse, the HVP between standard and railguns due to shielding and different sabot requirements on the latter.

The HVP is literally design to be used between railguns and Powder Guns, that is it whole purpose.

It has all the need shielding built in, which isn't that much, to its systems stock. The Army kept that cause they kept working on the railgun til recently and it was cheaper to do so. And as futureproofing since it was seen that the railgun will returned in the future after it was cancelled.

Bigger issue is Sabot requirements and that just means it needs to fit and seal. Which is something you can do manually, see the various addon for shells. It be very easy to have an automatic system that pulls the railguns sabot for the 5 inch one and put it back as need. Sabots are largely friction held with a small clip to ensure a clean seperation when it leaves the barrel.

And even if they don't go for a switching station.

You still be seeing massive savings cause the Sabot is the CHEAP part of the shell. The HVP itself is the expensive bit and thats design to be universal between the guns.

 

[Not James Stockdale]

Do you have any additional info on the HVP performances missiles? Very curious to see what the performance is like. I’d also expect a 25-40mi range vs subsonic targets.

BAE has a one-pager on their website (https://www.baesystems.com/en/product/hyper-velocity-projectile-hvp). Their ranges for (presumably) surface-to-surface fire are in there.

Range
> 50 nmi (93 km) from Mk 45 Mod 4
> 40 nmi (74 km) from Mk 45 Mod 2
> 70 nmi (130 km) from AGS
> 43 nmi (80 km) from 155mm Tube Artillery
> 100 nmi (185 km) from EM Railgun

2) I don’t think you’ll get any reasonable rate of fire with that, for missile defense applications. For striker that’s more acceptable.

I have not seen any information about that. The BAE page says the EM railgun has a firing cycle of 6 seconds, but I have no idea if that is applicable to the current version of the GA 32 MJ railgun. Also, there are a ways to design the capacitor set-up to allow for burst firing with longer recharge periods, which may be preferable when engaging a time-on-target ballistic missile attack.

3) I wouldn’t expect any improvements to rail life without either lower energies, a larger system, or an architecture change.

Do you have any good reason to say this? There will be fifteen years of materials science between the end of the Dahlgren railgun program in 2021 and the earliest that these guns could get into service in the 2030s.

The Japanese system is much much smaller, to the point that it likely has a different barrel life. As it is, I don’t think the Japanese system as much if any military use. As it fires unguided APFSDS.

This article (https://www.navalnews.com/naval-new...s-image-of-railgun-installed-on-naval-vessel/) says the Japanese got to 120 shots at 2 kps, which is close to the same velocity as Dahlgren's 32 MJ railgun, but firing smaller projectiles. It also says that the Japanese are looking into using the railgun against hypersonic missiles and are developing anti-air projectiles.

You won’t be able to reuse, the HVP between standard and railguns due to shielding and different sabot requirements on the latter.

The BAE brochure has illustrations of three different HVPs for 5" guns, 155 mm guns, and railguns, but only gives one weight and payload figure.

 

[Scott Kenny]

What does this “thing” bring to the table that makes it worth paying as much as a Ford class (or even more according to some estimates)?

Only when you count the development costs. And guess what? Only the hull costs need to be developed out. Almost all the combat systems are off the shelf. SPY6? OTS. Mk41? OTS. APM/CPS? OTS, developed for Zumwalts.

It also has enough growth margin, which most of the ships are just flat out of.

I hope we aren’t trying to cram too many disparate systems & roles into a single design, risking program failure through low production, and creating deployment-use conflicts. I feel like the CVN Bodyguard and Strike roles require separate large warships, which could reduce the displacement and increase the number of hulls.

Role: CVN Bodyguard - A CVN escort’s primary roles are AAW & ASW, since the CV’s air group can handle surface threats & strike at much longer range than Mk.41-sized systems. A CVN bodyguard needs Aegis CMS, a large SPY-6, a high-mounted surface search radar, an AAW command center, a lot of VLS, a VDS, a MFTA, a hangar, a flight deck, an ability to replenish underway, and systems for self protection (RAM, JQL, laser, SLQ-32 & decoys, a remote weapon like Mk.38 mod 4, probably a 5” gun, & maybe NSM). Probably a big ship, but something closer to a Zumwalt’s displacement could mount this gear a remain comparatively affordable for the number of escort warships 10x CVSGs and 10x ARGs are going to need.

Role: Surface strike - Do strike-oriented surface warships need to mount all strike weapons in one design, or can systems be mounted on different ships to account for differing logistics requirements and mission characteristics?

Railgun is not particularly for surface strike.

HVP is primarily for ABM.

Can CPS & SLCM-N be replenished underway? Unlikely due to missile weight and volume of propellant at-risk, right? So why aren’t we thinking about mounting these on a separate “Long-range Strike” warship that can fire missiles & return to port for reload, and avoid taking bodyguard capabilities away from the CVSG for most of a wartime deployment? Such a warship could economize by shedding a big radar or ASW gear (rely on multi-mission FFG [Constellation-successor] escorts?), and only mount self-protection gear (SPS-80/TRS-4D, modest number of VLS [or none at all if CPS cells can accommodate Mk.41 canisters], RAM, JQL, SLQ-32 & decoys, & Mk.38 mod 4), as it would be unlikely to enter the first island chain to launch CPS or SLCM-N missiles. It wouldn’t need a hangar & might only need a flat space for VertRep, versus a full Seahawk-capable flight deck. Depending on propulsion needs, this ship could be comparatively small, reducing cost, & increasing the number of ships eventually built. It would not regularly steam with a CVSG, given its port-based missile replenishment needs.

There's a reason the USN is putting SPY6 on everything. Several, actually.
Economic: only need one school for all the radar techs. Only need one set of spare parts.
Operational: no distinct class sensor fits to reveal what ship the enemy is detecting. Only SPY6.

I have trouble with a rail gun use case as part of a CVSG. With respect to shooting enemy ships, how does investment in a rail gun (& associated SWPC required) really increment US Navy capability when Tomahawk block Va & aircraft can quintuple (or more) a rail gun’s range?

If a rail gun is meant to attack land targets (I’m not really seeing the cost/benefit in this use-case either, unless the Navy can expand munition types from a small dart to something fragmentary), shouldn’t the US Navy consider a smaller Medium-range Strike warship mounting a rail gun (maybe), a 5” gun, MLRS, self-protection gear (SPS-80/TRS-4D or smaller SPY/6 arrays, a modest number of VLS, RAM, JQL, SLQ-32 & decoys, & Mk.38 mod 4), and a hangar & flight deck for AH-1Ws or MH-60S to provide CAS to the Marines? Such a warship could range from something Burke-sized (just the 5” gun & MLRS) to a Zumwalt-sized warship (IEP propulsion if the rail gun materialized) meaning that it could also mount towed sonars to handle ASW and thus self- escort. It might travel with an ARG, or it might support Marine LCTs in chokepoints.

There was supposed to be a "shotgun" version of the railgun round. Something that broke into a bajillion tungsten cubes and sandblasted the impact area.

Not sure it was ever more than a concept, though.

Yes, this would create a need for three separate designs (currently the US Navy’s weak link), but taking this approach puts more hulls in the fleet for similar cost (distributing risk in combat) and more appropriately maps systems to disparate missions.

And that's the big problem. Navy cannot design multiple new ships at once.

I’m not talking about the lead ship though. All estimates indicate the per-ship follow-on cost to be at least $10 billion, which is absurd for anything that’s not a nuclear-powered supercarrier. Unit cost needs to come down at least 50% before this ship even starts making sense.

I'm not sure that's correct.

As @Not James Stockdale posted, the methodology does not seem to scale, because DDGs cost more per ton than carriers do.

My cost sanity check would be cost per ton of LHA/LPDs, plus the GFE of the Burke IIIs.

Why not brush off the BMD San Antonio concept? It has plenty of SWaP & growth room, and replacing the diesels with turbines should boost speed to ~30 knots. It may not be “sexy”, but it’s way more practical than this vanity project.

The San Antonio hull basically cannot do 30 knots. Not without orders of magnitude more horsepower.

 

[DJK]

Growth margin is always good but its a bit of a chimera in some ways. We know the latest squirrel-cheek Burkes are making the old hull puff a bit hauling all that additional load but the full load displacement increase since the Flight I is only 1,400 tons - not bad over 38 years

Growth margin doesn't have to mean adding all sorts of weapons to create a "does everything" ship. Sure the navy cant prioritise anything because this looks like unlimited budget, but some things are also just nice to have. CPS, BMD, and AAW commander in the same hull? Makes more sense to put those capabilities into a modular insert like was planned for DDG(X). Figure out how much power generation and space needed for the essentials first. If not every role requires it, then it might be a case for only some ships getting that configuration. Honestly, CPS seems like the sort of thing that belongs on a dedicated strike platform.

Of course it's possible. Take a Zumwalt, put the two Mk110s back on the hangar, replace the FWD AGS with a Mk45 or railgun, replace the aft AGS with CPS and you're almost there. Yes, yes, we want drone countermeasures, and a few other things, but that's not going to cost you 10k more tons.

Mk-45 I can see as place holder for a future rail gun, but slow rate of fire not ideal for any AA use, and an AAW commander or BMD cruiser doesnt need any other kind of naval gunfire.

 

[DWG]

Do you have any good reason to say this? There will be fifteen years of materials science between the end of the Dahlgren railgun program in 2021 and the earliest that these guns could get into service in the 2030s.

Of which likely at most a decade is applicable because of the need to test, freeze the design, and productionize it. And you might be lucky to get the full decade. And that's presuming any applicable breakthroughs, which isn't guaranteed.

 

[EmoBirb]

Makes more sense to put those capabilities into a modular insert like was planned for DDG(X).

It doesn't make sense in reality though because these modularity concepts have always failed, led to issues, cost increase and ultimately couldn't deliver on the promise of flexibility

 

[Sferrin]

It doesn't make sense in reality though because these modularity concepts have always failed, led to issues, cost increase and ultimately couldn't deliver on the promise of flexibility

*cough* LCS.

 

[cccgong]

Hi,

I believe that USN escorts have traditionally been estimated at 20kts because the USN had spent alot of effort developing their amphibious vessels to travel at 20kts, and wanted their escorts to be able to effectively escort them. As such, if the higher end transit ranges for an escort is lower than 20kts, then the entire group may have to transit at a lowerr speed.

In addition as previously noted I believe that the US Coast Guard's Deepwater Program System Performance Specification had requirements based partly on the desire to escort 20kt merchant ships (though I can't find a specific reference to it at this time, but I will keep looking for it).

As for range being irrelevant for a ship like the LCS I disagree. I worked for one of the design teams during the design phase of those ships and meeting the range requirements was an issue for the design, and we ended up developing a revised endurance calculation method to account for the reduced resistance associated with the decrease in displacement that would occur as fuel was burned, as opposed to the method used for more conventional displacement ships previously.

[And for the car analogy, that may not be such a good example, as I understand it, range anxiety can be of great concern for people with electric cars, where the ability to charge may not necessarily be just around the corner.]

I'd be very curious to hear more about your experiences on the LCS ship design, if you're willing to share.

BAE has a one-pager on their website (https://www.baesystems.com/en/product/hyper-velocity-projectile-hvp). Their ranges for (presumably) surface-to-surface fire are in there.


I have not seen any information about that. The BAE page says the EM railgun has a firing cycle of 6 seconds, but I have no idea if that is applicable to the current version of the GA 32 MJ railgun. Also, there are a ways to design the capacitor set-up to allow for burst firing with longer recharge periods, which may be preferable when engaging a time-on-target ballistic missile attack.

Do you have any good reason to say this? There will be fifteen years of materials science between the end of the Dahlgren railgun program in 2021 and the earliest that these guns could get into service in the 2030s.

This article (https://www.navalnews.com/naval-new...s-image-of-railgun-installed-on-naval-vessel/) says the Japanese got to 120 shots at 2 kps, which is close to the same velocity as Dahlgren's 32 MJ railgun, but firing smaller projectiles. It also says that the Japanese are looking into using the railgun against hypersonic missiles and are developing anti-air projectiles.

The BAE brochure has illustrations of three different HVPs for 5" guns, 155 mm guns, and railguns, but only gives one weight and payload figure.

I imagine the firing cycle doesn’t mean a sustained fire rate. We'd expect something around 33% efficiency which would be ~100 MJ per shot. I'm very skeptical they are generating 17MW in a cargo container plus caps for storage. Even if we assume they are just doing storage, 17MW is a huge amount of power to be pulling from your ship's IEP.

There's mostly papers and extrapolation from them with known data points. The Japanese one is a pretty good, point of comparison. They are getting 120 shots with a ~5MJ rail gun. However rail erosion scales exponentially with energy so a 32MJ system will be much worse. Also they were making tweaks to the rails until pretty close to the end of the program. Something like the 10MJ gun would have much better rail life.

Regarding material advancements, this is a pretty niche field. Once the funding dries up likely a year or two before program cancelation not much work will still be done. Also as DWG says there is a need to productionize, and many material advancements end up being very difficult to scale.

The current Japanese gun doesn’t have the projectile volume for a guided projectile. They need to develop something new for an anti air projectile.

This is the volume they have to work with.

 

[CastleBravo]

Given the fact that the railgun is specifically stated to use HVPs, the primary role is probably terminal ballistic missile defense. The 32 MJ railgun was a muzzle velocity of roughly 2.5 kps with a 40 lbs projectile, and the HVP weighs 44 lbs. The performance of the HVPs out of the railgun would probably give a protected area similar to PAC-3 or maybe PAC-3 MSE (20 - 30 mile footprint), if the HVPs can eventually work in that role. Even if a BMD HVP costs $1 million compared to a $100k anti-missile HVP, that's 1/4 the cost of a PAC-3 MSE and a ship this big could easily carry 1,000 HVPs without touching the VLS. This is the same thing that the AGS tried to do with the Zumwalts (store 500+ PGMs outside the VLS) and there was little technically wrong with the AGS once development was complete.

The 5" guns are probably also there primarily for defense against anti-ship missiles. The HVP has already demonstrated effectiveness against subsonic sea skimmers and supersonic sea skimming targets are probably within the realm of possibility for additional development. Given the ballistic range of HVPs out of the 5" gun, I would expect a useful range comparable to ESSMs, and the guns with HVPs would again be cheaper than missiles and would not take up VLS cells. In both cases, even if the HVPs are less accurate than missiles, salvo and magazine sizes could easily make up the difference unless there was an enormous performance gap.

40lbs at 2.5km/s would be about 57 MJ. Those performance figures are likely from the old development goal of a 64 MJ EM cannon.

PAC-3 is the premier terminal ballistic missile interceptor because the active MMW seeker and Attitude Control Motors give it hit to kill accuracy. HVP won't have either of those. As far as I can tell, HVP will be command guided. Maybe optical tracking could give the resolution needed to hit a ballistic missile with a command guided cannon round, but that seems unlikely to me. It should be great against cruise missiles and OWA drones though. It should also be extremely effective against surface targets.

I wonder what a resurrected Mk71 8"/55 could do with HVP though. That gun had something like 44 MJ muzzle energy. Imagine an 8" smoothbore cannon firing a ~60lb subcaliber HVP at the same 1.8km/s (Mach 5.2) velocity some tank guns shoot APFSDS at.

 

[AngrySquirrel]

Missed opportunity, Mk71 8 inch with GA’s LRMP, or the Zumwalt’s AGS also with the LRMP.

 

[Forest Green]

40lbs at 2.5km/s would be about 57 MJ. Those performance figures are likely from the old development goal of a 64 MJ EM cannon.

PAC-3 is the premier terminal ballistic missile interceptor because the active MMW seeker and Attitude Control Motors give it hit to kill accuracy. HVP won't have either of those. As far as I can tell, HVP will be command guided. Maybe optical tracking could give the resolution needed to hit a ballistic missile with a command guided cannon round, but that seems unlikely to me. It should be great against cruise missiles and OWA drones though. It should also be extremely effective against surface targets.

I wonder what a resurrected Mk71 8"/55 could do with HVP though. That gun had something like 44 MJ muzzle energy. Imagine an 8" smoothbore cannon firing a ~60lb subcaliber HVP at the same 1.8km/s (Mach 5.2) velocity some tank guns shoot APFSDS at.

IIRC the BAE SYSTEM railgun made 33MJ, and fired at M7.5, which amounts to a 10kg (22lb) projectile. The same energy would fire a 40kg projectile at M3.75. I think the 64MJ target existed when they were thinking about it being a predominantly surface attack weapon but they've since shelved that idea. However, it was resurrected for the purpose of BM/hypersonic defence IMO, where projectile size and range is less important than the muzzle velocity and the ability to forgo having to store cartridges or propellant charges in exchange for more rounds.

That said, it may also have surface attack as a secondary capability, which will be more intended as a deterrent in a close-range naval standoff situation (that may arise as a result of blockades etc.) rather than land target attack.

 

[AngrySquirrel]

I had the displeasure of watching the video upon release, minutes of my life I won't get back (so I would not recommend watching the whole thing, or do at 2x the Speed). His...guest went on a whole tangent about the history of battleships and carriers and acted like the intent was to put a naval gun fire support into the water, as was the case with the ill fated Zumwalt.

When reality is that the BBG(X)/Trump-Class whatever it's being called only shares it's terminology with battleships of old. It's a very large surface combatant with heavy emphasis on long range land attack and anti-ship missile armaments. IIRC he argued that you'd get 3 Burkes or something along the line for a single one of these. Well, for one, they don't compete but supplement each other. But that aside, these ships will be build from the ground up with modern AAW flag facilities designed into them, as far as I understood statements published so far it will take over the role of the lead surface combatant of a given strike group from the obsolete Ticonderoga Class ships. That's something the AB does not truly offer, even the Flight IIIs are more so interim solutions and fully maxed out. Anything short of a full redesign won't give you the ability to get this hull further along. The BBG(X) on the other hand will offer the opportunity for a clean sheet design and with this displacement and size, even after being scaled back a bit in the future (which I find likely), it will offer so much real estate that the growth margin will be significant.

In essence it's yet another attempt by the Navy after stuff like Cruiser Baseline or CG(X) to finally get a true Tico replacement into the water. A capable large surface combatant with the sensors and armaments necessary to effectively persist in naval warfare in the 21st century. That they had to slap a battleship designation on it and call it the Trump-Class was a very small price to pay.

That all of this has been fairly obvious so far, and that BBG means it's a guided missile battleship (CPS taking the role of the "big guns" in this day and age) went completely past this gentleman. Meaning he went on this entire tirade because it's only a battleships in name, in an age where the type of a warship is as arbitrary as it gets (Frigates, Destroyers, Cruisers, Battleships, all just ways to describe a large warship with guided missiles)

Most nuanced take I’ve seen so far, most either mock the idea or outright dismiss it.

 

[Scott Kenny]

Overall agreed, but my assumption at this point is that BBGs aren't meant to form SAGs with DDs. Burke is much of BBG capability minus offensive capability - which is the entire point), but little of its survivability. It honestly doesn't make too much sense to operate them together in harm's way.
Only BBG and USVs; same for new FFX, which are their own thing(lo in fleet structure, rather than Lo in HiLo to Burkes).

That was me copying the old 600-ship Navy from the 1980s, swapping BBGs for CGs in the carrier groups and BBGs for Iowas in the SAGs.

CPS/Dark Eagle plus SM6Blk1b would make a pretty solid threat to surface ships. Nothing on earth, not even an Aegis ship, will like a bunch of Mach 4+ high divers coming in at ~700+km. (It's not clear just how much farther the 21" SM6Blk1b would fly over the 13.5" SM6Blk1a, but the SM3Blk2A that shares the 21" boosters has approximately 1/3 more delta-vee so I'm guessing at about 1/3 more range versus surface targets) SM6 is admitted to hitting surface targets at 500km, and I think that was a 13.5" missile.

Role: CVN Bodyguard - A CVN escort’s primary roles are AAW & ASW, since the CV’s air group can handle surface threats & strike at much longer range than Mk.41-sized systems. A CVN bodyguard needs Aegis CMS, a large SPY-6, a high-mounted surface search radar, an AAW command center, a lot of VLS, a VDS, a MFTA, a hangar, a flight deck, an ability to replenish underway, and systems for self protection (RAM, JQL, laser, SLQ-32 & decoys, a remote weapon like Mk.38 mod 4, probably a 5” gun, & maybe NSM). Probably a big ship, but something closer to a Zumwalt’s displacement could mount this gear a remain comparatively affordable for the number of escort warships 10x CVSGs and 10x ARGs are going to need.

Think is, Navy was wanting to put CPS missiles onto the Carrier Bodyguard, likely because there's no other place to put them. There's only 3x Zumwalts, and at best they can take 8x APM tubes, each with 3x CPS missiles.

Installing the APMs into DDGX meant that the ship had to give up the gun, and nobody was comfortable with that idea.

But if you get a big boss who likes big boats and he can not lie, you pitch an idea to make the new ship a BBG twice the size of your DDGX proposals, with all the missiles you need, CPS included, and guns.

Role: Surface strike - Do strike-oriented surface warships need to mount all strike weapons in one design, or can systems be mounted on different ships to account for differing logistics requirements and mission characteristics?

Can CPS & SLCM-N be replenished underway? Unlikely due to missile weight and volume of propellant at-risk, right? So why aren’t we thinking about mounting these on a separate “Long-range Strike” warship that can fire missiles & return to port for reload, and avoid taking bodyguard capabilities away from the CVSG for most of a wartime deployment? Such a warship could economize by shedding a big radar or ASW gear (rely on multi-mission FFG [Constellation-successor] escorts?), and only mount self-protection gear (SPS-80/TRS-4D, modest number of VLS [or none at all if CPS cells can accommodate Mk.41 canisters], RAM, JQL, SLQ-32 & decoys, & Mk.38 mod 4), as it would be unlikely to enter the first island chain to launch CPS or SLCM-N missiles. It wouldn’t need a hangar & might only need a flat space for VertRep, versus a full Seahawk-capable flight deck. Depending on propulsion needs, this ship could be comparatively small, reducing cost, & increasing the number of ships eventually built. It would not regularly steam with a CVSG, given its port-based missile replenishment needs.

If Mk41s can be reloaded at sea then SLCM-N can be.

CPS is the size of the original Polaris missiles, which were reloaded off the sub tenders, but still in ports IIRC.

Missed opportunity, Mk71 8 inch with GA’s LRMP, or the Zumwalt’s AGS also with the LRMP.

AGS has burned a lot of bridges politically, once Congress cut the ship buy and made it non-viable to build a production like for LRLAP. Hard, but not impossible to convince Congress to fun new ones. As long as you successfully beat it into Congress' heads that they need to buy at least 60 guns and enough ammunition to feed them all.

Mk71 8"/55 or /60 is 50ish year old technology, but could be developed. The US is apparently making 8" shells and can make 8" gun tubes.

What might be do-able would be Vertical guns. The predecessor to AGS, which IIUC fits into a pair of Mk57 slots as a single mount. A ship would have pairs, one per side. At the time vertical guns were discarded, trajectory shaping was not developed enough to allow for a single gun to fire at targets within 14nmi of the ship.

 

[DJK]

It doesn't make sense in reality though because these modularity concepts have always failed, led to issues, cost increase and ultimately couldn't deliver on the promise of flexibility

Which modularity concepts were they? A preconfigured hull insert has never been tried as far as i know. Yes trying to get USN to containerise endless wishlists will never work. But an insert that accommodates command staff or weapon systems shouldnt be so hard to transfer from design to reality. If the design can be agreed on and finalised!

 

[AngrySquirrel]

Cool, I didn’t know vertical firing guns was even a thing

 

[Foo Fighter]

You know, for what they have been spending, they could perfect the catapult. The winding mechanism would be a bit of a bear but considering the growth of suggestions for flywheels as space propulsion, why not?

 

[Ainen]

Btw, not exactly BBG(X), but it came to me that in priiinciple, if railgun can serve ABM/AA/ASuW, you can throw out all missile batteries(fuel, large warheads) altogether.
Then in stage two build a hybrid propulsion with smaller dispersed generators(as to avoid any big single spaces, and overall distribute them evenly across the ship). Same also allows to avoid big and vulnerable shafts.

Net result may be very hard to sink with non-nuclear weapons, while retaining functional teeth - ship hull effectively turns in one big, thoroughly compartmentalized torpedo defense system without major critical spots, jeopardizing its safety...

 

[MadRat]

I've seen conversations about BBG(X) being based on the San Antonio class. I would think something more inline with the old Iwo Jima class, converting some deck and hangar space for VLS and a proper bridge, makes more sense. Either way they need to be capable of 30+ knots by the time they deploy. Instead of aiming for a hanger of 25 helicopters, go for 6-10. F-35B should be able to launch and recover on what is left of the deck. It obviously needs to be more powerful than Zumwaly by the time you are done.

 

[EmoBirb]

Most nuanced take I’ve seen so far, most either mock the idea or outright dismiss it.

I think the idea of a large surface combatant with a state of the art sensor suite and diverse missile load out should always be taken seriously.

People just get hung up on superficial stuff like the name, BBG designation and the rail gun. If it was designed in China, called Type 055A, and being labeled a CG the outrage would quite frankly not exist at all.

The Navy wants their Ticonderoga replacement, they wanted it for decades and this is just their newest shot at it, pulling every string they find to get the Trump administration to back the program. I don't see anything wrong with that. People just like to hop on the outrage train for the sake of it.

 

[cccgong]

Btw, not exactly BBG(X), but it came to me that in priiinciple, if railgun can serve ABM/AA/ASuW, you can throw out all missile batteries(fuel, large warheads) altogether.
Then in stage two build a hybrid propulsion with smaller dispersed generators(as to avoid any big single spaces, and overall distribute them evenly across the ship). Same also allows to avoid big and vulnerable shafts.

Net result may be very hard to sink with non-nuclear weapons, while retaining functional teeth - ship hull effectively turns in one big, thoroughly compartmentalized torpedo defense system without major critical spots, jeopardizing its safety...

I don’t think it makes much sense to get rid go the missiles due to rate of fire issues. Each 32MJ gun would basically the same as having a single arm launcher. Expect you now have scary ~17 MW electrical requirements for each one to achieve 10 rounds/minute per gun.

At best they are a supplement to reduce engagement costs and get more interceptors out quickly.

Regarding power requirements the Zumwalt with 78 MW of generation needs to slow down to at 30 knots to use all of its sensors. If you tack another 17MW of usage onto along with larger radars and more required propulsion power. You’ll likely want 120 MW of power. That should be well covered by 3 MT-40s (35MW output) and some diesels.

Or more ideally we go with a A1b nuke plant at 125 MW, and that would allow to it keep up with CVN during long transits without refueling. This would make allot of sense especially as it’s likely to serve as a CV protector as one of its main roles. But the production rate on reactors is likely quite limited.

 

[Brett Davidson]

I've seen conversations about BBG(X) being based on the San Antonio class. I would think something more inline with the old Iwo Jima class, converting some deck and hangar space for VLS and a proper bridge, makes more sense. Either way they need to be capable of 30+ knots by the time they deploy. Instead of aiming for a hanger of 25 helicopters, go for 6-10. F-35B should be able to launch and recover on what is left of the deck. It obviously needs to be more powerful than Zumwaly by the time you are done.

This? Not exactly a 'battleship' but Ballistic Missile Defence ship on a San Antonio hull.

AI overview, sorry. Can't be arsed retyping. From 2016.

The image is a model of a conceptual Ballistic Missile Defense (BMD) ship based on the U.S. Navy's San Antonio-class (LPD-17) amphibious transport dock hull.

• The concept was displayed by Huntington Ingalls Industries (HII) at the Sea-Air-Space Expo in 2013.
  
  
• It incorporates an Aegis-type phased array radar atop the superstructure.
  
  
• The design featured numerous Vertical Launch System (VLS) cells and a railgun.
  
  
• The intended role was to provide homeland or regional missile defense, freeing up destroyers for other missions.

Also:

https://thaimilitaryandasianregion..../lpd-based-ballistic-missile-defense-ship-usa

https://www.reddit.com/r/WarshipPorn/comments/qmedh4/a_conceptual_model_from_2013_showing_huntington

View: https://www.reddit.com/r/WarshipPorn/comments/qmedh4/a_conceptual_model_from_2013_showing_huntington/

(Compared with other sources, I think they have the 2013 date wrong.)

One comment: Honestly this is what I suspect is the basis for the “Defiant class”

From 2:10:

View: https://www.youtube.com/watch?v=cqQiyiior40

 

[Firefinder]

Or more ideally we go with a A1b nuke plant at 125 MW, and that would allow to it keep up with CVN during long transits without refueling. This would make allot of sense especially as it’s likely to serve as a CV protector as one of its main roles. But the production rate on reactors is likely quite limited

The reactors builds are THE limiting factor of the CVNs, adding more will just increase that time.

That before adding in the Major issues of.

Tripling the crews needs, going from 12 people in total to 50 minimun is nothing to snuff at.

Add in needing to add 2k tons just for the reactor compare to just that for 4 MT30s for having a third more power with enough fuel to out run the rest of the fleet?


Nukes just... Suck compire to modern GTEs and Diesel Gensets.

 

[johnpjones1775]

Of course it's possible. Take a Zumwalt, put the two Mk110s back on the hangar, replace the FWD AGS with a Mk45 or railgun, replace the aft AGS with CPS and you're almost there. Yes, yes, we want drone countermeasures, and a few other things, but that's not going to cost you 10k more tons.

The also want 96+ VLS for none hypersonics, but 16 mk41 isn’t going to cost you 10kn tons either

 

[Nx4eu]

https://www.navylookout.com/the-str...il-of-trumps-battleship-plan-for-the-us-navy/

Still no funnels I see. The current layout known to the public is complete bogus. Such a poor preliminary CG to show off.

 

[Scott Kenny]

The also want 96+ VLS for none hypersonics, but 16 mk41 isn’t going to cost you 10kn tons either

It will cost you the bow gun, though.

Not enough space for APMs, Mk57 PVLS, a block of Mk41s and a 5".

 

[cccgong]

It will cost you the bow gun, though.

Not enough space for APMs, Mk57 PVLS, a block of Mk41s and a 5".

I believe were older Zumwalt proposals with 128 vls cells of MK57 and 2 guns. I believe the extra cells were after the super structure around the helopad. You should be able to remove one of the guns for APMs.

However where would the lasers go, and they may want additional power generation for them + a larger radar. That could be done by swapping out the MT30s for uprated LM6000 (2x LM9000 is more than needed), but that might be a good bit of modification.

 

[DJK]

Still no funnels I see. The current layout known to the public is complete bogus. Such a poor preliminary CG to show off.

Nice quote from that article:

The next naval war may be decided not by the ship that looks the most impressive, but by the side that can lose ships and keep fighting. A fleet dependent on a few ‘silver bullet’ capital ships is brittle

 

[Scott Kenny]

I believe were older Zumwalt proposals with 128 vls cells of MK57 and 2 guns. I believe the extra cells were after the super structure around the helopad. You should be able to remove one of the guns for APMs.

There's already a row of Mk57 on the port&starboard sides of the helo deck. 20 cells each side, I think, though it may only be 16 aft and 24 forward.

However where would the lasers go, and they may want additional power generation for them + a larger radar. That could be done by swapping out the MT30s for uprated LM6000 (2x LM9000 is more than needed), but that might be a good bit of modification.

Lasers would go in place of the 57mm guns.

 

[johnpjones1775]

It will cost you the bow gun, though.

Not enough space for APMs, Mk57 PVLS, a block of Mk41s and a 5".

T

There's already a row of Mk57 on the port&starboard sides of the helo deck. 20 cells each side, I think, though it may only be 16 aft and 24 forward.




Lasers would go in place of the 57mm guns.

The ships will be getting ready to decommission by the time lasers will be viable weapons.

 

[cccgong]

T

The ships will be getting ready to decommission by the time lasers will be viable weapons.

They are already viable CUAS weapons even with the current low powered versions. Especially the small UAS you were worried about for some reason in another thread

 

[Dilandu]

The next naval war may be decided not by the ship that looks the most impressive, but by the side that can lose ships and keep fighting. A fleet dependent on a few ‘silver bullet’ capital ships is

Problem is, that its cleary not USA now. So maybe its time to really deviate from conventional logic & try for unconventional approach - i.e. ships that are less likely to be sunk?

 

[DJK]

Problem is, that its cleary not USA now. So maybe its time to really deviate from conventional logic & try for unconventional approach - i.e. ships that are less likely to be sunk?

That was the old conventional battleship. To make that a more realistic scenario, put the CPS ona separate platform that can be tasked independently of the CBG escorts. Make the AAW escorts cheap enough for a cut down version to eventually become the ubiquitous replacement when Flt II and Flt IIA are due for retirement. A BBG cant be numerous or have 40 or 60 built, while a DDG(X) could have the hull plug left out after the first 20ish AAW Commander versions replace the CGs.

 

[cccgong]

That was the old conventional battleship. To make that a more realistic scenario, put the CPS ona separate platform that can be tasked independently of the CBG escorts. Make the AAW escorts cheap enough for a cut down version to eventually become the ubiquitous replacement when Flt II and Flt IIA are due for retirement. A BBG cant be numerous or have 40 or 60 built, while a DDG(X) could have the hull plug left out after the first 20ish AAW Commander versions replace the CGs.

There is no cut down AAW version possible. DDG(X) as it stood was the minimum viable product for today's threats. It wouldn't have worked well for things 10 years from now let alone at the end of its 30-40 year service life as there isn't much if any growth margin.

A 20-25kt cut down more sensible BBG(X) still wouldn't provide the same relative leap in capability we had going from the Kidd's to the AB's. That's the level of capability improvement needed for a ship to serve for 40 years. This is also ignoring the fact that in those 40 years naval development stagnated to 10-15 years (1992- mid 2000s).

 

[johnpjones1775]

They are already viable CUAS weapons even with the current low powered versions. Especially the small UAS you were worried about for some reason in another thread

They’re not but whatever you say