Developing Submarine for transporting large sums of cargo

So the Americans have theorized making submarines that are capable of going behind Enemy lines and deploying a amphibious assault force but the Soviets have managed to go midway through developing one of these types of submarines. Project 621 and project 748. This could also be used for transporting everyday materials and relief supplies to besieged cities. Saw someone from some image board mention full metal panic and how in the fictional universe someone managed to buy the unfinished hull and modernized it for a PMC group. I’ve never watched this show but I figured it would be pretty cool if someone used it for regular cargo transportation. The org I theorized in creating helps facilitate trade and order in the Sea of Japan or east Korean Sea between all countries, it would be helpful to make such craft such as this. I wonder how feasible it would be and the cost estimates for such a feat and a gauge on the quality of the modernized equipment. The inside would be cramped but it could be comfy with quality of life improvements.
It’s probably sitting somewhere rusting up in some dock somewhere in Russia, I wonder how much it is to purchase the incomplete hull. Is there any (obviously free) 3d models of it, preferably ones I could put in blender and experiment with?

On a side note: also interested in Beluga whale taming.

Its more cost efficient to use a boat…

nuclear subs use nuclear power because it takes a lot more power to run a submarine…

Same with aircraft carriers and that’s a boat that carries lots of stuff.
Diesel subs use Diesel engines because it’s more cost efficient to run a sub that way albeit louder. Hybrid subs use battery when they need to because it’s quieter. The nuclear subs is built as a compromise between silent power and effective power. It’s slower but it bypasses the need for total air and sea supremacy to do a navel landing. Like I said it can be used to provide relief aid to besieged port cities.
If you look at conflict in world war two like the Marianas island chain or the Papa new Guiana conflict you realize that they needed another airport each other island to leap to the next island because not only do they need to bomb it but for scout planes to scout so the landing force doesn’t get in the middle of a navel adversary and for other combat vessels to intercept and engage any navel force present. The Sub bypasses the total navel and air supremacy at the cost of speed and carrying capacity. Another benefit is you are immune to multi-mach speed anti-ship missiles so you don’t need to equip your sub with any of the anti missile systems, just use quieter engines.

Second, the need for regular cargo ships to be submerged can be used in cases where piracy is rampant like in the Red sea, the Persian Gulf, Singapore, sea of Bengal, and so on. It’s much harder to board a ship underwater than it is to board one on the surface. Yes, it’s more cost effective to roam around on surface ships but it’s also riskier and you are vulnerable.

yeah I guess with piracy and all that its safer to passengers, on the other hand its more unsafe because any small leak in the hull could spell doom at depths.

I saw that movie with Tom Hanks and piracy, all he needed was just a machine gun and they wouldn’t have boarded his ship.

I don’t know about you but I rather deal with water pressure than people, especially strangers. I tend to get socially anxious and awkward.

Think of it as the three little piggies and the wolf. the two piggies made prefabricated houses and the third made himself a bunker. Adolf Wolf came in and blew the other two up. It’s better to be prepared and not need it then need it and not have it as a rule of thumb. make bunkers and subs and the costs to be slightly higher than pay for buildings that’ll collapse when the next earthquake or tropical storm rolls in. Rather make one coast guard ship that stays afloat in all conditions than two commercial ships that’ll sink if it ever tips over the moment it encounters a particularly large wave. It’ll probably be good to make cargo ships with the same principles the coast guard makes their vessels. Subs can tip and turn and twist all they want, as long as the ballast tanks are not punctured it will not sink to the bottom of the ocean.

they have anti-sub missiles now, investing in subs seems like a lot of money for something that isn’t invincible.

They also have bunkerbusters. Who cares if it isn’t invincible, it’s better than the alternatives. They have way less missile/torpedoes and sonobuoy than they have missiles and radar.
Another way is just making low profile radar deflecting fast speedboats but then that loses its purpose of effectively carrying large sums of cargo.