COSTAL DEFENSE FORTIFICATIONS AND ARTILLERY.
This subject will be broken down into 4 sperate parts: History, Armaments, Permanent Fortifications and Expeditionary Options. There will be a second part that covers protection from attack by missiles and aircraft.

That is part of a larger conversation about force protection and deception tactics.
Coastal defense forts or significant concept in protecting strategic chokepoints and as a way of protecting harbors and naval facilities.

From the star Fords around the Caribbean, Fort McHenry to Fort Sumner there are many impressive examples. The most impressive in my opinion is that of the Puget Sound “triangle of fire” which consisted of six forts primarily, Casey, Flager, and Worden.

Designed to protect Seattle from attack, I grew up fascinated by these massive defensive structures. However, if not their time of construction they were rapidly being outpaced by technological advancement.

With the rise of naval strike aircraft and more accurate naval gunfire they were now held at risk. However, in this thread I will illustrate not only is this no longer the case, but sure installations can help counter the current undersize fleet we currently have.

With the soon-to-be fielded longer shooting artillery accurately ranging out to 60nm, & compact anti-ship missiles like the NSM. Land based fortifications can be affectively equipped to function in an anti-ship role, Previously impossible.

it is also worth noting currently tube artillery is being developed for even further ranges with the hopefully soon to be fielded 120nm guns and even the proposed strategic long-range artillery capable of accurate fire out to 1000nm.

This depending on the price per shell, makes coastal artillery an economical and effective option.

By leveraging already existing artillery units and providing them with additional training to function in this new role conventional artillery games a significant new capability that currently the US is lacking.

Conventional artillery units will need to be augmented with additional equipment and personnel familiar with marine operations. However this is not an insurmountable hurdle, and the same systems that are used for permanent installations and Expeditionary installations can be ...

reused. This will allow for greater training even During times of peace.
While we do have these weapons systems capable of these roles currently there is no successful way to employ them in this manner. In order to fill this capability gap,

I propose the development of two separate kinds of coastal artillery primarily being permanent and Expeditionary fortifications. permanent fortifications will be well developed facilities capable of hosting batteries for extended periods of time at vital choke points.

Expeditionary forts will be constructed during times of crisis and conflict to control strategic chokepoints without having to station warships or to seal off these supply lines to friendly units with sea mines.

Before we delve further into this it is important to discuss their operational and tactical functioning.

Permanent facilities are not to continuously host gun batteries instead the batteries should be located at centralized bases enabling easier peace time management and lowering operational cost.

Also by only moving guns into The Fort during preplanned exercises and crises a new strategic signal is possible that has previously been unavailable or involve the costly movement of ships or manpower .

These forts should be minimally manned and with no gun’s present are relatively unimportant locations requiring only a small maintenance and security Garrison. These forts will not be like those of old with statically mounted guns around a small heavily defended building or site.

instead It will consist of multiple firing positions per gun Distributed more widely around a central control site. This makes it much more survivable as the guns can rotate through firing positions making targeting active gun emplacements costly as most will be empty.

By rotating guns four or more times a day neutralizing a single gun could take many shots. across the entire Battery, Over 100 targets would need to be engaged accurately and quickly for there to be any chance of it being neutralized.

There are very few navies in the world that can affectively gather the necessary intelligence and have vessels capable of targeting such a facility.
The same multiple firing sites and rapid deployment system is also possible for Expeditionary coastal fortifications.

By exploring recent rapid construction methods like hesco barriers and new construction machinery, naval construction unions could and place a new fortress in as little as 48 hours. As with the permanent installation the construction of fortification and moving in guns provides a

new signal similar to that of moving a strike force into a region without the cost of having to take warships off of other assigned duties.
It is important to briefly mention the accuracy of these batteries and what would be required. The guns do not need to have the same level

of hit probability or effectiveness as that of surface combatants. This stems from their inherent survivability and their ease of replacing damage unlike that of a warship. They merely need to pose such a threat though attempting to maneuver past them is too much of a risk and

that would be too costly to attempt to remove the battery from the fight. a hit rate of 5-10% would be greater than what would be necessary to provide sufficient deterrent to attempt to run the fortifications. Accuracy as low as .5-1% could accomplish this. With the guns that

have been discussed earlier the 5-10% accuracy would be achievable. This coupled with short range anti ship missiles, while less survivable more accurate, would allow even a rapidly constructed fort to change the strategic and operational calculus of opponents for a low price.

Coastal fortifications can offer a cheap and effective way to seal off chokepoints without draining ships away from the main effort, along with many other capabilities. If the fortresses are provided with organic ISR assets like drones, Cheap surveillance aircraft, or aerostats;

they can Provide a high degree of spatial awareness to combat commanders. If small boat/ Boarding Teams are also stationed with them they can help it implement blockades and sanctions at a lower cost, then deploying warships to the same point.

They also help provide a secure bastion Within the littorals, that would otherwise be nonexistent.
With a broad understanding of how fortresses could be employed and their functioning / capabilities, OK it is important to discus locations of them.

The primary contender for early emplacement of permanent facilities, is the Bearing Sea /Strait. This often-overlooked choke point where significant areas are on US land is the only entrance to the Arctic domain from the Pacific. Buying placing fortifications here a low-cost way

of controlling the street is not only available it also means warships can be taken off taskings from this during times of crisis when they would be needed elsewhere. This also enables the securing of a northern route to the Atlantic during summer months if USCG assets or

otherwise detained or unavailable. The first sites should be located at Saint Lawrence island on the western edge of the Stewart Peninsula and little diomede. For the limited areas unreachable by currently fielded guns that will soon be in reach of guns US aircraft capable of

equipping anti-ship weapons would be able to deny movement across the small area unreachable in the Russian waters.
Expeditionary bases can be employed at chokepoints where is politically possible to construct them during times of crisis. A perfect example of this would be the

Strait of Malacca, where one or two forts could be built on either or both side of the straight. Thus, denying freedom of movement from the Indian Ocean To the Pacific or vice versa during conflicts.
It is important to note if the channel is too wide to be effectively controlled

by forts alone see mine should be in placed in order to constrain maneuverability. This is a tried and true method to control ship access and maneuvering. By coupling this with coastal fortifications even wide channels can be cheaply controlled. However, as the entire width does

not need to be mined this line of communication and supply does not need to be unreachable or impossible to cross for friendly vessels. While many countries boast navies, few both navies that cannot successfully attack the fortifications, and even fewer boast the mine sweeping

capability to be able to cross a straight protect in this manner.
This can seamlessly integrate with the new USMC doctrine on land based sea denial. by serving as a long term anti ship capability verse the rapid and emplacement of MC units to grant sea denial for Short term

operational needs, Expeditionary fortifications can convert these gains into long term Holdings allowing critical combat units to return to frontline duty without losing the strategic gains that were made. As there will always be a limited number of marine core units that will be

needed for other tasking during conflict this can take pressure off of these assets similar to how it lessens the need for ships to hold these positions.
There is so much work to be done, however with the right planning and training we could see conventional artillery units

become capable of sea denial operations with standard equipment if augmented with a small contingent of equipment and personnel. This has the capability of creating a new threat rapidly that countering will prove to be difficult.

By leveraging already existing skills and equipment in new ways we can gain A2/ADC capabilities that previously were unavailable for significantly lower cost than attempting to develop new weapons systems or field new assets.
Looking forward to Part 2,

I will cover construction of Expeditionary and permanent facilities, along with their design And a further look into their operating principles. I will also further explore who exactly man's the facilities and how they function during peace in

wartime along with relevant jurisdiction. Along with this I will cover air defense for these facilities along with how protecting these sites should fit in with a broader emphasis on Deception tactics and new technologies that are available now.

I would like to thank @Jayleo110, @CatLadyFA, @lostmidwestern, and @austins_coffee, for talking with (read putting up with) me initially about this subject, and let me use them as a sounding board for my idea.