any info about the 40,000 tonne French Battleships from the 1920's?

[Gladiatorfromtds]

Ight so I'll keep this quick, but I was scrolling on navweaps.com and founds something very interesting. Apparently, there was a french 45 CM gun designed in the 1920's.

Now, perhaps that may not sound correct but what really made me curious was the article itself. It discussed plans for a 40,000 Tonne French battleship armed with said guns.

Does anyone have any info about these battleships? How many main guns they carried? What their armoring was? Speed? Secondary armament? I'm really curious to know.

Here's the link for anyone curious: http://www.navweaps.com/Weapons/WNFR_177-45_m1920.php

It's also worth noting the book cites it's source for this info from the book "French Battleships of World War One" by John Jordan and Philippe Caresse. I do not own this book, but perhaps one of you guys do and could help me.

 

[fortrena]

From the looks of it those ships would have been fitted with 380 or 406 mm guns. Three variants were seemingly looked at, with (standard?) displacements of 40,000, 42,500 and 45,000 tons. In the fall of 1920, the Marine national envisioned the possibility of constructing 11 of those behemoths (4 + 4 + 3) between 1926 and 1940. Given France's economic situation, its wish to build up its lighter forces (destroyers, cruisers and submarines), the Washington Treaty, etc., that very ambitious program was put aside.

Oddly enough, a prototype of the Modèle 1920 450 mm gun was tested in 1929. That 45 caliber weapon allegedly had a range of 51 900 metres (almost 56 800 yards). Shells weighed 1 380 and 1 397 kilogrammes (about 3 045 and 3 080 pounds). Muzzle velocity was 850 or metre/second (slightly less than 2 800 feet/second). The weapon had some issues, however. Only one was made.

Interestingly, the French Armée de Terre briefly envisioned the possibility of using that weapon as a super heavy railroad gun.

 

[Dilandu]

Does anyone have any info about these battleships? How many main guns they carried? What their armoring was? Speed? Secondary armament? I'm really curious to know.

Alas, only speculations - and the gun itself, which was build and tested (and according to some sources, still exist today).

Personally, I suspect that the 1920s battleship was designed as follow-up to "Normandie" and "Lyon" line. With similar general architecture, but with one 45-cm gun replacing each pair of 34-cm guns. At least on paper, such replacement looks pretty possible; the gun sections of French quad turrets were spacious. The armor scheme likely would also be changed with more emphasis on deck protection.

So my assumption - an enlarged "Lyon" with bulges and single thick armored deck (instead of traditional French many thin decks), armed with four dual 45-cm turrets (based on quadruple 34-cm turred design) and with speed about 24-25 knots (like it was proposed for post-war redesigns of "Normandie"-class). Quite probably the secondary armament would be 155-mm guns in dual turrets (like on first French post-war cruisers), instead of 138-mm in casemates.

 

[Tzoli]

That is what I suspect. If any design work was done on these battleships I can see 4x2 45cm armed either evenly spaced as an option was likely not the favored one (though a Lyon preliminary drawing shows this layout), a Lyon layout with superfiring pair aft or a Kongo style with a superfiring pair forward. I can also imagine a possible 3 turreted version with slightly more speed or less displacement aka cost. A quad 45cm turret is a possibility but not highly likely considering the size of such a turret! A triple too was possible but I do not know any designs at this time of a proposed triple turret of any calibre for the French Navy except for a Slow and Fast Battleship study of 1914 with 3x3 38cm (Slow) or 2x4,2x3 34cm (Fast) turrets:

https://www.secretprojects.co.uk/threads/french-pre-ww1-battleship-proposals.35602/

 

[Dilandu]

a Lyon layout with superfiring pair aft

A likely possibility, yes. A bow superfiring pair (like on Kongo), IMHO, seems unlikely - upper weight would be a big concern, and French battleships of 1910s tended to be bow-heavy already.

 

[Gladiatorfromtds]

That is what I suspect. If any design work was done on these battleships I can see 4x2 45cm armed either evenly spaced as an option was likely not the favored one (though a Lyon preliminary drawing shows this layout), a Lyon layout with superfiring pair aft or a Kongo style with a superfiring pair forward. I can also imagine a possible 3 turreted version with slightly more speed or less displacement aka cost. A quad 45cm turret is a possibility but not highly likely considering the size of such a turret! A triple too was possible but I do not know any designs at this time of a proposed triple turret of any calibre for the French Navy except for a Slow and Fast Battleship study of 1914 with 3x3 38cm (Slow) or 2x4,2x3 34cm (Fast) turrets:

https://www.secretprojects.co.uk/threads/french-pre-ww1-battleship-proposals.35602/

Thanks! I do think it is a shame that we don't have any true info on the design based on the mere tonnage and the calliber of the main guns, but I do think this is definitely a possible layout and armament.

 

[Phoenix_jz]

Unfortunately, there is no such available information, as the best information we have available suggests that there was no serious design effort initiated in the first place.

After WWI, the Marine Nationale did want to move to future battleship designs to correct the many flaws that were now apparent in the design of the Normandie and Lyon-classes (which were viewed as not being possible to salvage). In order to cope with the 16" designs that had started construction during WWI for the USN and IJN, and the large designs expected to follow, the MN was itself looking at 400mm to 450mm guns, of which the latter became preferred.

This came within the context of a larger naval program that sought to provide a coherent framework for procurement from 1919/20 to 1940, and did indeed call for 40,000-tonne (normal displacement) battleships - eleven of them! There was both a 'minimum' program of staggering scale and a 'normal' program who's scale was surely only intended to give the finance ministry a heart attack - I'm not aware if that one was actually priced out or not. The minimum program was, and is reported at the bottom of the following table that includes the makeup of either program;



This program was developed from 1919 to 1920, but did not progress very far both due to the reality of what funds would be available, and of course the start of the Washington Naval Conference in 1921. Such as it was, the MN was well aware that they would not have the funds to lay down either the battleships or the larger cruisers until after 1925, and as such had decided to monitor the developments of foreign battleships for the time being before developing a design of their own.

With this being the case, and the WNT cutting off any chance of large battleships five years before anything could have been laid down anyways, there was really no time for anything substantial to have been developed.