French Lyon class battleship design found in KM archives

[Nick Sumner]

Found by Sanglune and originally posted in the KM archives mega-thread, this is a fascinating drawing. The version of the Lyon class presented here is very different from the depictions in both Jordan's French Battleships of World War One and Breyer's Battleships and Battle Cruisers 1905-1970 which are in good agreement with each other. Below is a low res scan from Jordan, which is very similar to the drawing in Breyer.



The only other configuration for Lyon that I'm aware of is from Warship International (though it seems when I photocopied it I neglected to make a note of the date). As can be seen it's very different from the one in Breyer and Jordan.



I have to ask if the version from the German archives is speculation? The fruits of espionage? Derived from captured documents? Is there any more information on the drawing?

 

[Nick Sumner]

Small update as posted by Roodbaard58 in a now missing thread. The following is from pages 377-379 of the Journal of the United States Artillery, Vol 44, 1915







As can be seen, this variant is in good agreement with the one from Warship International. So have we found 3 of the 5 designs?

 

[Roodbaard1958!]

I found another reference to the Tourvilles. Can anyone make a copy of the post in the U.S. Naval Institute Proceedings, volume 41, July-August 1915 where on page 1280 is mentioned that there were 5 Tourville-designs with some details. Perhaps this post includes drawings

 

[TomS]

 

[Roodbaard1958!]

Flottes de Combat 1917 presents this drawing

 

[Archibald]

Sixteen guns ? boudiou (as we say in southern France) that's pretty impressive firepower !

 

[Tzoli]

But only 34cm. Hiraga designed one with 4x4 41cm in 1920/21

 

[Dilandu]

Sixteen guns ? boudiou (as we say in southern France) that's pretty impressive firepower !

Just four more than 12-gun Normandie)

But only 34cm. Hiraga designed one with 4x4 41cm in 1920/21

If I recall correctly, for post-war Normandie a 40-cm gun was suggested (each pair of 34-cm guns would be replaced by single 40-cm gun), and at least theoretically it would be possible to fit post-war French 45-cm guns on the same basic also. So if Lyons were (somehow) actually laid up and finished, they most likely would boast quite a different main battery.

 

[Nick Sumner]

Sixteen guns ? boudiou (as we say in southern France) that's pretty impressive firepower !

Possibly on the same reasoning that led to the Mogami, Baltimore, Southampton, Worcester and Minotaur class cruisers. 'Smothering fire.'

 

[Dilandu]

Possibly on the same reasoning that led to the Mogami, Baltimore, Southampton, Worcester and Minotaur class cruisers. 'Smothering fire.'

Generally because French navy already have quite good 34-cm gun and promising design of four-gun turret, and did not want to waste time developing completely new weapon. French Navy was already behind German in naval construction by 1914; they only have 10 modern battleships (of them 6 semi-dreadnoughts) in comission versus 17 German. And Italy and Austro-Hungary were also building up their battleline. So French didn't want to waste any more time than nessesary.

Also, French Navy have it's own - and not exactly incorrect - opinion about efficiency of gunfire. They generally dismissed long-range combat as inefficient, pointing on the experience of such battles as Yellow Sea; the low hit probability, combined with shells reduced velocity and sub-optimal impact angles (i.e. low armor penetration) basically means that long-range combat would be absolutely indecisive, with both sides running out of ammo before dealing sufficient damage. French admirals assumed that the battle would become decisive only on the distance of "guaranteed belt penetration", i.e. about 14-15 km max. For that range they optimized both the armor scheme - not so much to resist the enemy fire, but to limit the damage from penetrations - and armament.

What French - as well as Germans, who actually assumed generally the same combat ranges, albeit for different reasons (Germans assumed that visibility conditions in North and Baltic Sea would make long-range gunnery inefficient) - did not took into account, is the development of automated fire control system by Royal Navy. The director fire control, combined with Dreyer tables, allowed not merely for long, but for ultra-long range gunnery - i.e. sending plunging shots right through the enemy decks. The hit probability was abysmal, but even a single hit could maul a dreadnought; most of WW1 era warships weren't designed to resist plunging shots at all. So French short-range optimized scheme suddenly become completely inadequate to new conditions (not that Germans fared much better... French at least learned their lessons and designed their WW2 era battleships differently, while Germans repeated their old assumptions)

 

[Archibald]

The 340 mm guns on the Bretagne class (designed pre WWI) had limited elevation and thus range, exactly for the reasons well described above post.

 

[TomS]

It's interesting that the Jones drawing in the initial post probably does correspond to the Design B described in the USNI article above, complete with a midships turret à la Normandie. But the final design appears to have been a hybrid of B and C: four quadruple 34cm turrets but arranged in the style of Queen Elizabeths with all the turrets at the ends, resulting in much better end-on weight of fire.

A couple more snippets from the article (No easy way to capture the whole thing, sadly). For USNI members, the full (72-page) Professional Notes section is online as a PDF only; it has not been OCRed. It covers building plans for all the major world navies, leadership changes, etc.

https://www.usni.org/magazines/proceedings/1915/july/professional-notes

 

[Dilandu]

It's interesting that the Jones drawing in the initial post probably does correspond to the Design B described in the USNI article above, complete with a midships turret à la Normandie. But the final design appears to have been a hybrid of B and C: four quadruple 34cm turrets but arranged in the style of Queen Elizabeths with all the turrets at the ends, resulting in much better end-on weight of fire.

A couple more snippets from the article (No easy way to capture the whole thing, sadly). For USNI members, the full (72-page) Professional Notes section is online as a PDF only; it has not been OCRed. It covers building plans for all the major world navies, leadership changes, etc.

Seems like that. Albeit I suspect that the finalized design (if such were made) may be altered due to excessive weight of forward superfiring turret.

 

[Tzoli]

Anybody know more data on the various Lyon preliminaries? Like the 5x4 305mm armed version?

 

[MadRat]

Casemate 6 inch guns? Seems like a poor design decision in thst period. I understand that torpedo destroyers were a threat, but absolutely restricted firing arcs and the chosen front/back layouts seem to compromise armor around main guns. American open turrets on the decks with an ability for high elevation angles seems like it would have influenced the French to look for something with some kind of improved defense against airplanes.

 

[Tzoli]

Casemate 6 inch guns? Seems like a poor design decision in thst period. I understand that torpedo destroyers were a threat, but absolutely restricted firing arcs and the chosen front/back layouts seem to compromise armor around main guns. American open turrets on the decks with an ability for high elevation angles seems like it would have influenced the French to look for something with some kind of improved defense against airplanes.

Erm... that was the standard at that time. Only the US used gunports instead of casemates. And most navies used 6" secondary guns.

 

[Dilandu]

Casemate 6 inch guns? Seems like a poor design decision in thst period. I understand that torpedo destroyers were a threat, but absolutely restricted firing arcs

It was basically universal decision at this time. The anti-torpedo gun must be quickly trained toward the fast-moving target; so if you put it into the turret, it would require power drives, while casemate gun could be trained manually. The casemates also add to the armor belts, serving as parts of them.

and the chosen front/back layouts seem to compromise armor around main guns.

On French dreadnoughts, the casemates were basically a part of main gun defenses. You see, French Navy was mainly concerned about localizing the damage from penetrations. So they build ships as series of armored boxes, divided by thin armored decks. Such layout allowed them to not use heavy barbetters below forecastle deck; the turret supports were covered by casemate armor.

 

[Cjc]

What French - as well as Germans, who actually assumed generally the same combat ranges, albeit for different reasons (Germans assumed that visibility conditions in North and Baltic Sea would make long-range gunnery inefficient) - did not took into account, is the development of automated fire control system by Royal Navy. The director fire control, combined with Dreyer tables, allowed not merely for long, but for ultra-long range gunnery - i.e. sending plunging shots right through the enemy decks. The hit probability was abysmal, but even a single hit could maul a dreadnought; most of WW1 era warships weren't designed to resist plunging shots at all. So French short-range optimized scheme suddenly become completely inadequate to new conditions (not that Germans fared much better... French at least learned their lessons and designed their WW2 era battleships differently, while Germans repeated their old assumptions)

We're they wrong though? Even in battles we're one side had radar driven targeting the gun lines were not very far apart. And during ww1 there assumptions seem to have paned out in what little data we have, none of the actions in the north see were very far apart (often because of weather) and none of them were decisive.