Was the Char B the "Tiger Tank" of France?

[Bougnas]

Regarding the D1's development, I wonder if it wouldn't be wiser to downscale the B1 (multiple protos existed in 1926 when the D1 project started) rather than upscale the Renault NC, which was likely bound to handle the increase in weight, armor thickness and armament requirements poorly.

Without the 75mm hull gun and extreme trench crossing requirements, it should be possible to draw a new hull that is of the right size to fit at least a one-man turret suitable for the 47mm gun, a comfortable driver's position and a hull radioman but much lighter and smaller (shorter in particular) than a B1. I'd suggest also dropping the idea of making the turret universal to fit on the D1, B1 and FT, just make it compatible with the B1 and D1 and make the turret ring as large as possible on the B1 and set the turret ring for the D1 accordingly. We know we can at least get to APX 1 size which should be a bit better.
Do like Gen. Estienne did to create the second generation B1 prototypes, and pick the best automotive components of the 1st gen protos and downscale accordingly. Since there is no hull gun it should be possible to use a less complicated steering system (no NAEDER) and suspension. IIRC the B1 and NC type suspensions were similar.
This means that it should be possible to use a 120hp Panhard or preferably the 180hp V6 Renault engine of the first protos, which should be suitable for a vehicle of the weight of a D1. The lower weight relative to the B1 makes it possible to consider the 180hp Berliet diesel that was proposed later on for experimentation, although it's possible that it would have been quite bulky and unsuitable for current transmissions.

Regardless, the 180hp Renault engine would already sort of match the powerplant that was seen on the contemporary British Vickers Medium Mk III. I reckon that with this alternate D1 with a more suitable powerplant and a fighting compartment size closer to the D2, the new tank would be more viable for its time and would require less changes to become an alt-D2. It would likely still have been a tad expensive and too archaic to work in 1940, but it might be a better basis for future french medium tank specifications and developments, especially if the better power to weight ratio encourages keeping it in future tanks.

 

[McPherson]

Regarding the D1's development, I wonder if it wouldn't be wiser to downscale the B1 (multiple protos existed in 1926 when the D1 project started) rather than upscale the Renault NC, which was likely bound to handle the increase in weight, armor thickness and armament requirements poorly.

Here: Comments will follow...

Without the 75mm hull gun and extreme trench crossing requirements, it should be possible to draw a new hull that is of the right size to fit at least a one-man turret suitable for the 47mm gun, a comfortable driver's position and a hull radioman but much lighter and smaller (shorter in particular) than a B1. I'd suggest also dropping the idea of making the turret universal to fit on the D1, B1 and FT, just make it compatible with the B1 and D1 and make the turret ring as large as possible on the B1 and set the turret ring for the D1 accordingly. We know we can at least get to APX 1 size which should be a bit better.

St. Estienne seems to have some fixation with the 75 mm gun as fortification assault requirement which probably is why the Char B1 was arranged the way it was. It was a WWI lesson learned and a WWI requirement updated.

With that written, it "seems" logical that the assault gun would grow a turret to deal with enemy tanks that would try to stop the assault gun. The Char B is therefore, not a "tank" the way that we understand "tank". It is a Stug. It has a turret on it with a 47 mm gun, but let us not be diverted. It is the 75 mm gun which is the clue and that does not disguise the "primary function" of the Char B1. It is not a Tiger Tank. It is a Ferdinand. It may be that in the logic of the time in which it was designed, the assault gun with a wide trench crossing ability makes sense, but this device should be seen for what it was and if it is modernized, it must be modernized with those origin limitations and that function in mind.

Do like Gen. Estienne did to create the second generation B1 prototypes, and pick the best automotive components of the 1st gen protos and downscale accordingly. Since there is no hull gun it should be possible to use a less complicated steering system (no NAEDER) and suspension. IIRC the B1 and NC type suspensions were similar.

Here: Comments will follow...

If one wants a tank, then one must define "tank" as to purpose. The French in the 1920s, when the Char B1 originates had this idea in mind when designing the CharB1. (I am quoting wiki)

The Char B1 had its origins in the concept of a Char de Bataille conceived by General Jean Baptiste Eugène Estienne in 1919, e.g. in his memorandum Mémoire sur les missions des chars blindés en campagne. It had to be a "Battle Tank" that would be able to accomplish a breakthrough of the enemy line by destroying fortifications, gun emplacements and opposing tanks. In January 1921 a commission headed by General Edmond Buat initiated a project for such a vehicle. To limit costs, it had to be built like a self-propelled gun, with the main weapon in the hull. To minimise the vehicle size this gun should be able to move only up and down, with the horizontal aiming to be provided by turning the entire vehicle. The specifications included: a maximum weight of thirteen tonnes; a maximum armour thickness of 25 millimetres; a hull as low as possible to enable the gun to fire into the vision slits of bunkers; a small machine gun turret to fend off enemy infantry attacks, at the same time serving as an observation post for the commander and a crew of at most three men. Two versions should be built, one a close support tank armed with a 75 mm howitzer, the other an anti-tank vehicle with a 47 mm gun instead.

Notice that the original intent was to field two versions. One version was to mount a howitzer in the hull. The other was to mount a 47 mm AT gun in the same position. This would tend to keep the hull small, low and cheap to make.

Then some bright guy.;. suggested that the 47 mm gun be added as a turret on top of the howitzer version to combine the two functions and things got out of hand. The Char B1 GREW like a baby tiger kitten. It started out as a little fuzzball and then grew into a monster cat.

This means that it should be possible to use a 120hp Panhard or preferably the 180hp V6 Renault engine of the first protos, which should be suitable for a vehicle of the weight of a D1. The lower weight relative to the B1 makes it possible to consider the 180hp Berliet diesel that was proposed later on for experimentation, although it's possible that it would have been quite bulky and unsuitable for current transmissions.

If one goes back to the original requirement... (from wiki)

That is an assault gun, not a tank. If one wants to turn that into a tank, then the forward hull gun compartment in the glacis must be repurposed because that void is not going anywhere.

French Tanks of the Interwar Decades

Notice that side hatch on the right side of the tank, and the hatch in the firewall that allows access to THE MAINTENANCE TUNNEL to the engine compartment as well as to the Turret and to the forward gun compartment? Ehh... I am not convinced that the start project, the SRB, was the correct start path.

From Wiki.
Niet toegeschreven. - Pierre Touzin, Les Engins Blindés Français, 1920-1945, SERA 1976)

Elektronische reproductie van foto van prototype SRB-tank

That contraption was simply wrong from start.

Regardless, the 180hp Renault engine would already sort of match the powerplant that was seen on the contemporary British Vickers Medium Mk III. I reckon that with this alternate D1 with a more suitable powerplant and a fighting compartment size closer to the D2, the new tank would be more viable for its time and would require less changes to become an alt-D2. It would likely still have been a tad expensive and too archaic to work in 1940, but it might be a better basis for future french medium tank specifications and developments, especially if the better power to weight ratio encourages keeping it in future tanks.

KO'd French Char D1 | World War Photos

That is a D2

It started from this prototype.

Credits (^^^) (see next)

Tanks and Panzer!: Char D2 Medium Tank

Specifications
Weight	19.75 metric tonnes
Length	5.46 m
Width	2.22 m
Height	2.66 m
Crew	three
Armor	40 mm
Main armament	47mm SA34 Gun, later models 47mm SA35 Gun
Secondary armament	2x 7.5 mm MG
Engine	Renault 6-cyl petrol 150 hp
Suspension	vertical springs
Operational range	100 km
Speed	23 km/h

Source : Wikipedia
Comments (McP's opinion) The D2 is a start point. The engine and transmission needs work. Suspension needs to be altered for a wider track for floatation and for an added two tonnes for the new two man turret.

Welding in place of rivets is needed. The hull should be widened over the track loop with sponsons for ammunition stowage. The bearing ring race on the hull deck needs to be expanded over the new sponsions and a larger turret mounted for a two man crew to stand. The back of the new turret should be bustled (radio) and roof hatches for the tank commander/radio operator and the gunner installed.

Main gun should be a 47 or rather this 65 mm in autocannon form.

 

[Bougnas]

I meant it more in the sense of reusing B1 proto components for the basis of the D1 project rather than outright using the B1 as a basis for the D1.

The evolution of the B1 is interesting indeed, the turret was originally only meant for observation and taking out infantry. The hull mounting of the 75 was chosen because:
- it simply wasn't possible at the time to have a 75mm gun in an adequate turret for the weight required by Estienne.
- putting the gun low would allow the strike of low bunker embrasures at a minimum angle so with the greatest chance of doing damage.

The B1 was functionally the post-WW1 replacement for the Schneider CA2 and CA3 projects which never entered service, and the Renault FT 75 BS (which appeared too late to be produced in large numbers). The objective being to take out bunkers with 75mm fire. Estienne deemed "medium" tanks (that is tanks between 13 and 23 tonnes) to be the future as they were large enough to have adequate armament and protection compared to the lights, and small enough to be cheap, reliable and available in numbers as opposed to heavy tanks like the FCM 1A or 2C.

 

[McPherson]

I meant it more in the sense of reusing B1 proto components for the basis of the D1 project rather than outright using the B1 as a basis for the D1.

Okay, I can see that happen, IF St. Estienne wants an upscaled FT.

The evolution of the B1 is interesting indeed, the turret was originally only meant for observation and taking out infantry. The hull mounting of the 75 was chosen because:
- it simply wasn't possible at the time to have a 75mm gun in an adequate turret for the weight required by Estienne.
- putting the gun low would allow the strike of low bunker embrasures at a minimum angle so with the greatest chance of doing damage.

Probably good enough reasons for the 1919 conditions, but certainly by 1925, these conditions had to change?

The B1 was functionally the post-WW1 replacement for the Schneider CA2 and CA3 projects which never entered service, and the Renault FT 75 BS (which appeared too late to be produced in large numbers). The objective being to take out bunkers with 75mm fire. Estienne deemed "medium" tanks (that is tanks between 13 and 23 tonnes) to be the future as they were large enough to have adequate armament and protection compared to the lights, and small enough to be cheap, reliable and available in numbers as opposed to heavy tanks like the FCM 1A or 2C.

I will write that I had never heard of the Renault FT 75 BS. Frankly I did not conceive that anyone would be ingenious enough to put a 75mm low velocity gun into what is essentially an FT17.

 

[Bougnas]

@McPherson Do you think that it would have been better to keep the B1 in its "Stug with MG turret" layout or the OTL version?
I assume that such a version would have been lighter and cheaper, moreso if armor is kept at 40mm (or even 25mm as originally specified) and even moreso if horizontal traverse had been included from the start for the gun and a less complex steering system was selected.
But even then considering how many issues had to be corrected and how there was still some tinkering with components, I'm not sure that production could start before 1932 (the actual order wasn't made until 1934 but that's because the Infantry was worried about the cost and because the B1 might have been too heavy for disarmament conferences, but here the order could be made in 1932 as intended).

Such a B1 might thus stay in production from 1932 to maybe 1936-7 when a more modern successor is devised, and even with the economic situation of the time there could have been decent numbers ordered. This would free 1937-1940 for more modern vehicles that do not need that many efforts to mass produce. However that makes a tank with AT capabilities even more relevant. The old B1s would also probably be in a pretty bad state by 1940, but maybe it would have been for the best if the B1 had been this tank that was too old for war but would give very good lessons for the actual war?

Edit: Why the hell did the B1 not get any horizontal traverse for the 75 when the FT 75 BS did?

 

[McPherson]

@McPherson Do you think that it would have been better to keep the B1 in its "Stug with MG turret" layout or the OTL version?
I assume that such a version would have been lighter and cheaper, more so if armor is kept at 40mm (or even 25mm as originally specified) and even more so if horizontal traverse had been included from the start for the gun and a less complex steering system was selected.

That would leave the French army with an assault gun it did not want or at least one General Buat did not. As with most answers of that kind, it comes down ultimately to what did the French nation need, versus what it wanted, versus what it could afford. The question narrows down further to what the French army needed, versus what it wanted, versus what resources could be allotted to that army for its specific desired weapon system.

France's Rhineland Policy, 1914-1924: The Last Bid for a Balance of Power in ... - Walter A. McDougall - (pp100-105) it appears the standing French army was in such dire straits that a national mobilization would be required to execute the occupation of certain areas in Germany to compel adherence to the Versailles Treaty. I know it does not seem to apply, but the Rhineland crisis gives a good snapshot of just how stretched France's army was for resources and what constraints hobbled it. When it comes to tank policy, I think I would answer the core questions about the Char B program with the following caveats.

First, the French army of the 1920s, when this tank was designed and intended was not worried about Germany, so much as revolutionary Russia, so one wonders what the French general staff thinks? If it needs a tank to meet its requirement, and the threat that staff foresees at the time of the tank's design is RUSSIA, then why choose a close assault against fortifications tank? The conditions of combat to be expected would be more of a cavalry machine if the French army reacts to a Russian incursion and has to meet that incursion east of France (hopefully).

Second, the two guiding influences of French tank policy of the Char B initial design period are Jean Baptiste Eugène Estienne and Louis Renault. I know it appears ridiculous to suggest that these two men will be the main guides and influences to French tank policy in the interwar period, but look at who insisted on something like the Char B in its actual form and who built it? These two men would, because of their WWI lessons learned biases and their reputations (successes), have to influence the Char B1 result. They, together between them, would go for a bells and whistles project and hang what the materials commissions and/or the French army staff might want.

If I was in the materials commission and if I had the authority, but only knew what the materials commission members of the time should know?

a. I would be aware of the FT's success.
b. I would be aware of the St. Chaumont's failure.
c. I would have digested the artillery firepower as the core of combined arms WWI lessons learned of controlled methodical battle.
d. I would be very cognizant of the German army's 1918 ability to use anti-tank guns and rifles to knock out the big clumsy British tanks and to attrite the smaller nimbler French FTs.
e. I would be acutely conscious of the French manpower and resources crisis.

Therefore I would strenuously resist these tendencies...
---build it big.
---build it expensive.
---build it thin armored.
---build it in too few numbers.
---build it unable to cross ground.

The idea is to...build this:
Specifications... Mass 20.00 metric tons
................................Length 5.5 m (18 ft)
.................................Width 2.5 m (8 ft3 in)
.................................Height 2.5 m (8 ft 3 in)
Crew .....................3 or 4
Positions.............. driver is left front
..................................gunner is right of gun
..................................tank commander is rear of gunner
..................................radio is, or signal flags are behind him
................................. loader (if provided) is left of gun,
..................................otherwise that is the autoloader and ten shot magazine (think Bofors pom pom feed only sideways.)

Armor/hull...........60 mm front/glacis, 40 mm sides, 20 mm top decks, floor plates
Armor/Turret..... 60 mm mantlet, 40 mm cheeks, 30 mm bustle

Main armament................... 47 mm / L50 (70 rounds carried 25 APC 45 HE-Frag)
Secondary armament........ 2 × 7.5 mm belt-fed guns (4 belts of 250 per gun, 2000 rounds.) Yes I mean Hotchkiss, not Reibel
Tertiary armament ..............2 x 3 each 60 mm smoke discharger (smoke discharger, 1 bomb per tube) or 1 x 60 mm mortar (20 bombs)
Engine....................................... Renault 6-cylinder 9.5 liters diesel engine 186 kW (250 hp)
Power/weight........................ 9.3 kW/tonne or 12.5 hp / tonne
Suspension.............................. Vertical coil spring volute or Christie
Operational range................ 400 km (248 miles) road, 200 km (124 miles) cross country
Maximum speed ....................41 km/h (25 mph) road 20 km/(12.5 mph) cross country

Is it possible on a proto B1?

But even then considering how many issues had to be corrected and how there was still some tinkering with components, I'm not sure that production could start before 1932 (the actual order wasn't made until 1934 but that's because the Infantry was worried about the cost and because the B1 might have been too heavy for disarmament conferences, but here the order could be made in 1932 as intended).

That is an eight year development cycle. Too much bureaucracy.

Such a B1 might thus stay in production from 1932 to maybe 1936-7 when a more modern successor is devised, and even with the economic situation of the time there could have been decent numbers ordered. This would free 1937-1940 for more modern vehicles that do not need that many efforts to mass produce. However that makes a tank with AT capabilities even more relevant. The old B1s would also probably be in a pretty bad state by 1940, but maybe it would have been for the best if the B1 had been this tank that was too old for war but would give very good lessons for the actual war?

Given the hypothetical FT replacement specified instead of the St Chaumont replacement, the odds are that one goes straight into the G1 right away

Edit: Why the hell did the B1 not get any horizontal traverse for the 75 when the FT 75 BS did?

Because the 75 mm gun on the Char B1 is in the hull, while the 75 mm on the FT75 B5 is on top of the hull?

Weird WWII: Battleground Weird WWII: FT-17 "Mosquito" and ...

I honestly do not know if that is superstructure or a moving casemate mount. I do not think it is a turret.

 

[Bougnas]

It's a superstructure.

 

[SealTheRealDeal]

That would leave the French army with an assault gun it did not want

Until it changed its mind and wanted that.

 

[Bougnas]

Until it changed its mind and wanted that.

Well technically the ARL V 39 stems from another doctrinal role, that being covering the gaps between fortifications with a powerful 75mm gun. It was also very sophisticated with an optical rangefinder. For some reason the longer gun that was trialled on the Garnier-Renault ACL 75 wasn't reused on this one, maybe concerns with gun length during travel that were common in that era.

This monstrosity was merely a proof of concept prototype, based on the D3. Very underpowered (74hp for 18 metric tonnes!) but the whole point was testing the gun. Gun was lengthened to 34.8 calibers to increase MV to 640 m/s.

 

[McPherson]

Until it changed its mind and wanted that.

I will have something to write about this "mistake". ARL 44 - Wikipedia. The origins of this aberration, are "obvious".

ARL V39 image - Tank Lovers Group - Mod DB

Well technically the ARL V 39 stems from another doctrinal role, that being covering the gaps between fortifications with a powerful 75mm gun. It was also very sophisticated with an optical rangefinder. For some reason the longer gun that was trialed on the Garnier-Renault ACL 75 wasn't reused on this one, maybe concerns with gun length during travel that were common in that era.
View attachment 615571
This monstrosity was merely a proof of concept prototype, based on the D3. Very underpowered (74hp for 18 metric tonnes!) but the whole point was testing the gun. Gun was lengthened to 34.8 calibers to increase MV to 640 m/s.

(^^^)
Sometimes gadgeteers get in the way of practical men. Here is a fairy tale about three knights...

Let's call one Sir Gladeon Barnes, one Sir Jacob Devers and one Sir Leslie McNair and let's have them fight about this turkey?

M26 Pershing - Wikipedia

This is what should have replaced the Sherman if those three geniuses had figured out which way north was...

USA's T25 Medium Tank, T26 Medium Tank (archive.org)

Summary: Barnes wanted the bells and whistles, Devers wanted tanks in the field yesterday and McNair split the baby and would not make up his freaking mind.

Very much like the French G1 program.

McP.

 

[marathag]

One big problem of the T20/22/23 was low number of prototypes.
Somehow Chrysler made the sole T22 with a Cletrac diff in the rear with a Ford V8, less reliable than the electric drive T23 or the GM automatic in the T20

 

[Johnrankins]

Sometimes gadgeteers get in the way of practical men. Here is a fairy tale about three knights...

Let's call one Sir Gladeon Barnes, one Sir Jacob Devers and one Sir Leslie McNair and let's have them fight about this turkey?



Summary: Barnes wanted the bells and whistles, Devers wanted tanks in the field yesterday and McNair split the baby and would not make up his freaking mind.


McP.

To be fair to all three I think Barnes sometimes going to far ahead of the curve challenged weapons designers who came up with things like the Sherman Tank (a very good tank) , Devers kept things down to Earth ( Preventing some sort of an "American Tiger Tank") and McNair had a tough job trying to sort it out. It was a job the army got "mostly right".

 

[Jonathansouth]

From what I can tell it looks like it was similar to a slow Panzer III. Is that the best the British-French could do in 1940 or am I missing something? Maybe something based on the Valentine, if that is the case maybe they should have just bought from the Brits. Hard for French politicians to go for though.

The Valentine was a derivative of the A10 Cruiser using the same suspension and gun and Engine but up armoured sacrificing a little bit of speed and operational range but the Valentine project didn't start until 1938 so it would have been too late. I've always thought the best option for the French tanks would have been to base them around the Gnome Rhone Mistral Major Engine an Engine that was commercially availiable since 1929 with France having a strategic stockpile of several thousand of them especially when they stopped using it in the mid 30s for thier air force was exceptionally reliable and while being similar in size to the Engine used on the Sherman and capable of 650-700hp. Another option would have been the Hispano Suiza 12Y either that was availiable in the early 1930s and had almost identical performance and size figures to the Rolls Royse Meteor. France had a massive stockpile of Aircraft Engines rated in the 600-750hp using 87 Octane Fuel range sitting in warehouses for emergency second line fighter programmes as they had realised that by the mid 30s that Front line fighters needed engines in the 1000hp range. After the Fall of France the Germans used these engines on a whole myriad of projects from the Gigant transport plane to the HS129 Tank buster.

 

[Carl Schwamberger]

This one makes a lot more sense when considering the implications of the rangefinder & azimuth optics in the turret. That feature is not for weapons. Then there are the unarmed command vehicles built on the same chassis, but with the same optics & radio suite. Another clue is in the robust ammunition train in the notional formation these vehicles were speced for. Theres a few other features, but a armored assault gun unit does not need these features. A SP artillery unit does. Ultra azimuth optics for 360 use, high-powered range finders, radios, attachments for telephonic comm. to other points, a ammunition train, and what amount to a 1940 equivalent of the 1980s US FIST vehicle. Thats all of use to artillery. The nominal ratio of command vehicles to cannon vehicles, 1-3 or 1-4 depending on how you count & the source, matches the distribution of the Groupe Poste observation & command nodes of the light artillery Groupes of the French army.

Given the extreme forward thinking in this concept & its untested nature of its prototypes theres bound to be some flaws. The prototypes look over armored to me & the ergonomics may interfere with RoF. But the underlying concept is sound.

Some people get confused over the emergency use of the handful of the SAU40 version of this spec, in June 1940. Those that could run were hastily fitted with 47mm AP cannon & used as a emergency armored company during the defense of the Weygand Line in June.

ARL V39 image - Tank Lovers Group - Mod DB

Maybe I can dig up other images of both both the ARL & SAu vehicles later. This <: http://www.chars-francais.net/2015/index.php > Is the most useful site Ive found for French AFV. The various game sites seem to be error ridden & otherhwise less complete.

 

[Bougnas]

The Mémoire Des Hommes database is also very neat because you can actually zoom in on the blueprints and read things you rarely can on usual internet pictures.