Submersible Frigate SMX-25

[SteveDaPirate]

I stumbled across an interesting concept for a hybrid between a frigate and a submarine. The SMX-25 is designed to transit at high speed on the surface and then submerge upon reaching its destination.

This looks like creative way to get around the "There are only two types of ships: submarines, and targets!" problem. It's essentially fast attack missile boat with 16 VLS cells + submarine with 4 torpedo tubes. Operating in a semi-surfaced mode would keep a sail with sensors above water but drastically reduce the signature of the ship and its vulnerability to anti-ship missiles.

A design of this nature seems like it would be very well protected from most of the threats to surface ships without giving up the speed that conventional submarines are forced to sacrifice.

Now as far as I know, this thing is just Vaporware at the moment and may never see the light of day. The defensive and stealthy advantages of such a ship seem quite nice, yet it almost reminds me of WWII era submarines. I would think there would be a number of technical challenges to trying to operate both above and below the waves, and the ship may just end up doing a poor job of both.

[kato]

This looks like creative way to get around the "There are only two types of ships: submarines, and targets!" problem.

To me it actually looked like whoever came up with the concept read a certain Star Trek novel that involved just this kind of submersible frigate published about 15 years earlier.

Now as far as I know, this thing is just Vaporware at the moment and may never see the light of day.

DCNS' entire SMX line consists of vapourware concepts. Basically "what could we do" studies. SMX-21 had "modular payload packs" that would slot into a submarine hull, SMX-22 was a "detachable networked swarm" concept of submarines, SMX-23 was a low-cost coastal submarine updating 1960s warfare concepts with modern technology, SMX-24 revisited modularization - this time through stub wings with pylons -, SMX-25 was the semi-submersible frigate, SMX-26 was a very-shallow-water submarine that could drive on sea floor (on wheels). We'll see what SMX-27 will bring...

[Monash]

Didn't Get Smart have a 'submersible battleship' as a plot device in one episode?

[SteveDaPirate]

I thought it looked a bit to fanciful for the French to actually start building the things.

[Skywatcher]

If it's powered by waterjets under water (can't find any mention of propellers), how quiet is it going to be?

[SteveDaPirate]

From what I could tell, the object wasn't to be extremely quiet so much as to be able to hide from radar and anti-ship missiles when needed.

[gunnut]

French already tried this...in 1927.

French submarine Surcouf - Wikipedia, the free encyclopedia

[SteveDaPirate]

Surcouf may have been sunk on 18 February 1942 about 80 mi (70 nmi; 130 km) north of Cristóbal, Colón, while en route for Tahiti via the Panama Canal. The American freighter Thompson Lykes, steaming alone from Guantanamo Bay on what was a very dark night, reported hitting and running down a partially submerged object which scraped along her side and keel. Her lookouts heard people in the water but the freighter carried on its course without stopping, as they thought that they had struck a German U-boat, though cries for help were heard in English. A signal was sent to Panama describing the incident.[9][10] The loss of Surcouf was announced by the Free French Headquarters in London on 18 April 1942.

Run over by a merchant ship... what a way to go.