Railguns or lasers, even if possible on 1970s tooling, would be much too expensive to produce, and importing assemblies of them would be unfeasible - expensive, bulky and heavy; Airlift would require heavy aircraft (Expensive, and unlikely to take the risk of meeting Victorians), seaways are unavailable, and overland travel would risk both non-existent infrastructure and warlords.
While regular 155 mm or 127 mm artillery should be feasible, guided rounds are going to be way too expensive. Even M712 Copperhead might be beyond your means, depending on the state of industry in Chicago.
Chicago very likely doesn't have AESA radars in service, as those are 1990s tech (for military service), setting up production and working out the kinks would be a long and complex task - and trying to import them would meet the issues mentioned above.
Proposed waterjet propulsion might face the same issues of 1970's tooling; While 2070s designs might be superior, Chicago won't have access to them for quite some time - and then there'd be issues of introducing those waterjets into production.
That proposal would work if you had a decade (or more) to catch up with the outside world. You probably won't have that time; With NCR poised to rebel and FCNY likely drawing up plans to deal with Victorians on their own, you'd need to act fast to be relevant in post-Victorian America.
In order:
-We do not build railguns or lasers on 1970s tooling. We import them.
The Army's new 300kw laser is supposed to squeeze both the power generation and the weapon itself onto a standard military 6x6 truck, so its not a huge thing. And General Atomics Blitzer 32 MJ land railgun was supposed to fit on two semis, with most of that being power generation and capacitors.
We build the ships hull domestically, but we import the weapon systems, and the electronics, the computers, the encrypted radios, the combat management system, and the power systems. Just like we are currently importing renewable power equipment, the windmills and solar cells and batteries and supercapacitors and whatnot necessary for a clean electric grid in the 2070s and 2080s.
Just like we'll have to import cellphone networks wholesale.
Assuming we dont trust the Mississipi shipping route at that time for some reason, we ship into New York Port, stick the components on a hired or borrowed C-17(payload 77 tons) or C-5(127 tons payload) and fly it in.
There is little hope we can build something competitive on internal resources, at least not in a cost-effective manner. We could build the 127mm gun domestically, its essentially a 1960s design first built in 1971. But frankly setting up the tooling to produce equipment for a class of ships that at the most optimistic wont exceed 7 ships in number is a suboptimal use of our time and resources. Buy.
-127mm ammo weighs about 50kg per shell + propellant combo, and 155mm railgun ammo weighs roughly 20kg per round according to public info.So a full loadout of shells for one ship would weigh maybe 10-25 tons.
That's one or two C-130 Hercules flights, assuming ground logistics are blocked/unreliable in wartime.
-Modernish AESA radar is pretty much essential.
Because judging from recent Syrian experience with Israeli air raids on their territory, if you attempt to rely on 1970s/1980s/1990s/early 2000s radars in the next war against 2010s equipment in any capacity you are going to get punked.
-Waterjet propulsion dates back to the 1950s at least. But it is currently a commodity item that is seen today IRL on everything from pleasure boats to ferries to warships. Similarly, the diesels and aeroderivative gas turbines on modern warships are identical to the same power systems on civilian transport ships. Chinese domestic shipbuilding uses the same diesels for their frigates as they do for civilian transports. Buy.
-We
do have at least a decade or more before the Vics are ready to throw down again.
They are in a civil war that hasnt ended yet, and have already suffered pretty appalling personnel losses in their war with us.
And may well conduct further purges after the war is over.
They have a better industrial starting point than we do because of all the hydro power and electric cars they use, even if they were using lead-acid batteries, but they have a lower population education level by design. And its going to take time to stabilize their internal social order post-war, to switch their economy over from its dependence on looting the Lakes area, and to (further)enslave the PoC population for crash industrialization.
-This is supposed to be a late-2080s/early 2090s design. Lemme give you a timeline.
The year is currently 2076.
We're going to need to secure the old Fincantierri shipbuilding complexes around Marinette,WI and Sturgeon Bay, WI where they are currently building ~3400 ton LCS ships and intend to build the 7000 ton Constellation-class frigates IRL. Location matters for shipyards.
After that we'll need at least five years to invest in domestic shipbuilding on the Great Lakes for both civilian and military shipbuilding.
Import or build specialist stuff like cranes, train the shipbuilding crews who will build the ships, rebuild the old shipyards, establish the feeder supplies of high quality steel and a chemicals industry. And a munitions industry.
Then buy or beg or commission a design from foreign ship designers who remember what mistakes to avoid in a modern warship.
If California is unwilling or unable for whatever reason, the French natsec establishment will probably give us a ship design and specialists for free based on their animus for Victoria and Russia. Victoria is still occupying a French island off Canada.
Import technical advisers. Allow around eighteen months to build the first ship in the class.
The Chinese do it in roughly a year for a frigate that size, and parts of the WW2 US shipbuilding industry was capable of building 14,000 ton Cleveland-class light cruisers in twelve to eighteen months(Bethlehem Steel Corp's Fore River Shipyard, specifically), so I assume we will take around half again that amount of time for the first ship in the class, and reduce it to twelve months for subsequent ships.
Then train the actual ship crews.
Probably concurrently with shipbuilding, and probably either abroad, from whoever sold us the combat management system, or domestically with VR.
Two crews per ship so they can hand off to each other and avoid problems with fatigue. Add six months to work up the ship after commissioning.
Eight years at a minimum from "we want a frigate" to "I name you XXXX".
Ten years to build a class of four ships.
That's 2084 to 2086.
That proposal would work if you had a decade (or more) to catch up with the outside world. You probably won't have that time; With NCR poised to rebel and FCNY likely drawing up plans to deal with Victorians on their own, you'd need to act fast to be relevant in post-Victorian America.
I think I can safely say that FCNY are not going to start a war with Victoria. Gear up defensively, yes. Expand into New Jersey/Delaware/Maryland/Pennsylvania yes. Start a war no. They're the diplo/espionage spec faction, not the military spec. They have entirely too much to lose should a dumb Frog-7 equivalent rocket or Scud gets through their air defenses and crash into Manhattan.
And California has Japan-occupied Cascadia to their north and Japan-occupied Hawaii in the Pacific to worry about, in addition to internal political issues and Russian fuckery from out of occupied Alaska.
They are not setting up an expedition to come to the East coast to kill the Vics, much as they might like to.
However, Blackwell would need to have these Harpoonskis. Even just big numbers are somewhat problematic from a logistical standpoint - and then you have the issue of crews to be trained and formations to be raised...
Hezbollah has antiship missiles, and 300km+ ballistic missiles, and they sure as heck did not build them in Lebanon.
And that's in spite of all the Israelis could do in the way of intercepting foreign arms shipments from Syria and Iran.
So do the Houthis, despite the efforts of Saudi Arabia and friends to maintain a blockade.
Do not overestimate the difficulty involved in acquiring a single weapon system.
In a decade, Victoria might indeed have enough metal for such high-end combatants to be essential. The question is "Why are you giving him a decade?". Two-three years should be enough to build up Chicago's forces; By then, Victoria would still be recovering from their civil war, and they would still lack too many officers and technicians lost in Detroit campaign and "internal debates".
Because we need to eat a sandwich of our own.
We need to give our economy time to grow big enough to support a proper expeditionary war.
We need to train those parts of our military not called the Big Red One up from Korean War standards.
We need to procure industrial equipment and set up domestic production lines.
We need to feed and improve the lives of our people, who want both a better life and to murdering Victoria in the face.
We need to establish public health systems against the next epidemic. Settle domestic political issues, like immigration and refugees and the political status of petitioners to join the Accords. And establish diplomatic outreach abroad and to the rest of North America.
And grow the country by inducting more parts of America-That-Was into America-That-Is-Becoming.
Both for ideological reasons, and hardheaded growing our economic grunt reasons.
Now, some of the items on the wish list may be more avoidable than others. For instance, railguns are not essential to the ships' ability to function, and a more conventional chemical-propellant gun system will have the vast advantage that no matter what happens to our supply of overseas equipment, we can still make something to be fired out the gun. The railgun gets dropped, and the "procure expensive high-performance ammo for it" project is demoted to low priority.
Oddly enough?
Its probably going to be cheaper to acquire railgun ammo than powder gun shells.
At least, powder gun shells with antiship cruise missile capability.