The Hammer – 305mm B20 on Panther Chassis

Hello everyone,

today, we are going to talk about one vehicle, that could eventually appear in the game as “EU tree” tier 10 artillery. As you probably know, Czechoslovak branches are planned within that tree and every tree has to come with at least one artillery branch. What you might however not know is that of all the potential nations of the EU tree, there are only two, that can build a complete tier 2 to 10 artillery branches: Czechoslovakia and Sweden.

This is obviously the Czechoslovak candidate. Let’s have a look at it in more details.


Between 1946 and 1948, numerous (perhaps more than a dozen) various self-propelled gun projects were developed for the newly reformed Czechoslovak army. The exact numbers are not known and likely never will, as a part of the archive in Prague became flooded at some point and many precious documents were lost. What remains are the scraps of information, that take painstaking effort to piece together.

One of the challenges the Czechoslovak army faced was “what to do with all that collected German stuff” – during the war, Czechoslovak territory became a major strategic location, when it came to tank production (Jagdpanzer 38t and its variants, Marder, Grille, Sturmpanzer IV and others), but also repair. That meant that after the war, large amounts of German vehicles were recovered – either in state of repair from various workshops, or scattered around the countryside. Some the army got rid of immediately (Tiger and Tiger II tanks) because keeping them would be pointless (heavy, unreliable, no spare parts), some got pressed into service (Panzer IV, Hummel, Jagdpanzer 38t and others in limited numbers), but some the army didn’t really know what to do with (Panther).

Using captured equipment was considered problematic (not only because of spare parts, but also morally), it was always viewed as a stopgap measure, before the army could acquire something better and modern. After 1948, the question of “what” became completely clear, as the Soviets started selling Czechoslovakia some amounts of T-34/85 tanks and the license production was being prepared.

In the meanwhile however, numerous projects were prepared to bridge the gap, using whatever the army had at hand. Several of these projects proposed to use the Panther chassis for the heaviest type of artillery, including calibers of 150mm, 152,4mm and even 305mm.

The Vehicle

The project was proposed as superheavy artillery piece by Škoda on 10.10.1946. It involved – as said before – a Panther chassis (in case you are interested, you can read about the Panther itself in Czechoslovak service here) of an unspecified type. It was proposed to mount a 305mm B20 mortar project on it. The mortar at that point was proposed with two shells – a light 160 kg shell with the range of 10 kilometers and a heavy 235 kg shell with the range of 7 kilometers. At the point of this project however, the prototype mortar was not yet built. The muzzle velocity of the 160 kg shell was 430 m/s, the one of the heavy shell was 290 m/s. The mortar could fire in angles from 45 degrees to 75 degrees, but it could depress to 0 degrees for loading. The gun could traverse to 20 degrees on each side of the vehicle axis (40 degrees in total). Historical rate of fire was two rounds per 5 minutes.

The vehicle was built on “standard Panther chassis” (given the composition of vehicles captured at that point, it was most likely Ausf.G). The plans counted on removing a part of the Panther armor, reducing the weight of the entire vehicle to 45 tons. The vehicle was obviously not planned to fire on the move, a massive recoil brace could be deployed from the bottom of the vehicle between the tracks. The vehicle was to carry 9 mortar shells, but the engineers noted that their positioning on the top of the engine compartment (the big “drum”) would have a negative impact not only on the vehicle driving properties and engine lifespan, but also on fuel consumption, which was rated at 350 liters per 100km on the road and 700 liters per 100 km in terrain. The engine, powering the entire vehicle, was Maybach HL230 P30, rated at 700 horsepower, giving the entire vehicle a power to weight ratio of 15,5 hp/t. Maximum speed was listed as 25-30 km/h, theoretically up to 56 km/h. The crew was consisted of 4 men.

The project was relatively short-lived: as early as November 1946, Col.Trejbal (the commander of the Military Technical Institute) replied to Škoda with a letter, rejecting the project, citing the need for unified calibers and vehicles in the future. The project was however to be stored in the archives for research purposes. Škoda then moved their self-propelled guns to other (more perspective) platforms.

The Mortar

The mortar project itself however lived on.


The prototype was actually built and tested in late 1948 and early 1949 with following properties:

Caliber: 305mm
Barrel length: 5500mm (L/18)
Shell weight: 160 kg
Explosive within shell weight: 42 kg
Charge weight: 10,2kg
Shell velocity: 430 m/s
Range: 10 km
Elevation: 40-75 degrees
Weight (ready to fire): 9,3 tons
Weight (transport, with carriage): 16 tons

After some modifications, the project evolved into its ultimate stage, the B32, before it was scrapped and Soviet weapons were purchased instead. More about those can be found here.

In World of Tanks

In World of Tanks, as mentioned above, this would be the ultimate artillery vehicle of the EU tree (Czechoslovak artillery branch). While it is known that theoretically, there is a rule that each separate tree has to have its own artillery branch, the unwillingness of Wargaming to introduce new artillery kinda makes the future of this rule uncertain. The artillery balance in the game is a fragile one and introducing such a massive gun could upset it.

On the other hand, from balancing point of view, it’s completely possible to simply nerf the alpha and splash to appropriate levels of GW E-100 (a bit more perhaps) and to keep the rate of fire to a minimum. On the plus side, this vehicle could be fairly mobile (for a SPG), which I imagine could come in handy in CW and such. And, of course, hits from a 305mm mortar would make some unicums cry, so that’s a bonus as well :) In any case, this is a hot contender for the (only) tier 10 EU tree artillery, along with the (somewhat problematic) Swedish Bkan project.

As a bonus, this project could even be upgraded if needed (with the B32 mortar for example, but that is unhistorical).


M.Dubánek – Od bodáku po tryskáče

51 thoughts on “The Hammer – 305mm B20 on Panther Chassis

  1. Ooh, let’s have this, and let the arty hater tears flow more…to quote Star Wars:

    “Yes, yes, let the hate flow through you…”

  2. Are you mad? :D
    305mm mortar arties? Pass.
    I still think arty needs to be reworked. They say it is a anti camper weapon (what it is) but that also means the moment you stop to aim or try to use terrain features and stay in a good spot AT THE FRONT you’ll get shot to shit. If that is considered camping by the devs I don’t know. Think they want everyone to drive around like maniacs and shoot stuff.
    As long as an artillery player can point, click and hit me while I am on the move I consider it a broken game mechanic.
    But as we know from that nice letter, it is all our fault that we get hit by arty. Cause camping in the middle of the map and so.

  3. He is just desperatly trying to find some tanks to fit into WoT so he can have his beloved czech to play with.


    Im so fed up with reading about tank proposals who would otherwise be passed on after the first glance. 305mm calibre…. jeah sure Sturmtiger is impossible to balance (380mm, more or less “short range” derp – not an arty per se) but because its czech, 305mm on an arty is fine by your standards.

    Just leave it be, czech tech tree would suffer even a worse fate than japanese and chinese tree – only very very few people want to play these, heck, I bet mist americans don´t even know that had their own tanks.

    • It is a mortar, so the shell could be said to be less powerful than otherwise. Although it could open up some nasty possibilities concerning artillery that is T92+ in capabilities(French 280mm mortars anyone?). I’m sure the Czechs had some other mobile artillery projects that could be used if necessary.

    • Yep 305mm is fine if the alpha is balanced properly. 420mm, now that would be another matter. And why not? Plus, chill, the Czech branch will come, it’s just a matter of time.

      • There will still be an amount of trepidation about such a larger caliber, and presumably it would have a high arc. Combined with a mobile chassis, this could be like the GCC on steroids and everybody despises that already…

        But it does offer some opportunities to bring heavy French self propelled artillery to the field, so that is something.

    • well..i would be more respectful.

      Czechoslovakia was major exporter of tanks after WW2.
      According to ministry of defense, after WW2 Czechoslovakia did export more then 35 000 tanks and armored personnel carriers.
      And ~1970 Czechoslovakian army did have approx. 3000 to 6000 tanks + 4800 armored personnel carriers.
      For a country with 127 876 km2 and 15 700 000 people its quite impressive.

      This country was basically designed to be a bumper for USSR in case of major conflict.–vyplyva-z-knihy-o-cs–tankovych-silach–73826/

      • To be fair, the above poster didn’t deny Czech unit importance and value, just said that few would want to play them. I can understand that to an extent, since they do lack the prestige of other nations, but at the same time it would be a great shame to waste the amount of research that has gone into the tanks. I’d personally probably play them, although I’m much more heavily in anticipation of French vehicles and hope that as little as possible gets in the way of their inclusion.

  4. “Its hammertime!”

    I dont think that WG will ever put guns larger than 240 mm in the game (at least not into random battles) but if he does, i will grind it ;)

    • Eventually they’ll start running out of other things to do and will prolly go crazy on the artillery side to keep the good times rolling.

    • To be honest, the caliber is such a number, it does not necesserily need to corellate with the firepower (alpha, penetration, splash). The AVRE spigot mortar is a prime example (insane caliber, relatively low explosive power).

      • Apparently the shell weight was only half that of T92? Mortars in WoT typically have less power than howitzers (e.g., SU-5)

  5. I’m sick and tired of players complaining about arty calling it names like sky cancer and shit… MOST people who blame arties are IDIOTS and never played with arty before to se how fucking hard it is to hit a tank.
    Experienced players USE FUCKING COVER and stay in cover they don’t go in the middle of the field and start sniping like retards. If arty can hit you it’s your fault!!!!
    And play some god damn CW. ON some maps a good defence it’s impenetrable without ARTY.
    I don’t play arty, I have only one arty in my garage GW Panther. it’s the only arty I love to play with. Redblast [eu server]

  6. “And, of course, hits from a 305mm mortar would make some unicums cry, so that’s a bonus as well :)”

    Why do you hate better players, silentstalker?

      • In my experience whiny bitches are present in all skill levels of wot players.

        My personal problem with arty is the combination with xvm. It just makes gameplay for above average players extremely campy if you prefer not to get nuked in the first 2 minutes of the game. Even if you play an Aufpanther in t10 battles, t92 prefers to focus me moving full speed instead of E100s parking in the open. And i’m not even purple… So i can understand all the hate towards arty.

      • @SS: The problem with arty is not losing (this is the stupid WG excuse from their leaks), since most unicums (or anyone green and above) are winning more games than they lose, just by definition right. The problem is arty spoils the game play, it is NOT FUN to play with arty, it restricts the map, makes games campy, and throws in random luck instead of skill as a factor, THAT is the problem. We play the game to have fun, arty ruins that fun…its not fun for the arty player (as per WG lowest played vehicle type) and its not fun for the rest of the team…so obviously something needs to be fixed.

        • Well for me it sure is fun to play with the GW-E100… what makes you think arty players don’t enjoy arty ? Because seeing a Maus or E100 coming like a pro agains some tier 8 or 9 tanks and then hit by me for some 600-1600 hp and then saying ,,fuck it” is the best.

          Now I don’t have the arty anymore because I had to sell it in order to buy some meds, but the 261 is next on my list after I finish what I have now.

      • I’m not an extremely good player, but what I see as the problem with arty is this: I can outplay most players I meet in battle by combination of tactical knowledge and mechanical skills. I can’t outplay artillery. If I get spotted and I’m not in “arty-safe” cover, I will receive either direct hit or splash. So obviously I am being forced to camp, which greatly reduces my ability to move around the map and utilize my tactical knowledge. There is nothing else you can do. The core design of arty is so broken it removes the possibility of any counter-play.
        A strange anti-camping mechanic. The only way to avoid it is to camp.

      • Yet U define them as unicums, which is wrong and stupid. We all rage at some point and many unicums can just shrug off a bad game and hop into another without saying shit in chat. Ofc it´s easier to remember unicum whine, cause it´s one of the 99.99% players, yet you say nothing against the rest of red tomatos raging in chat.
        On the other hand you taking an initiative in developing that little reporting bot of yours is what I call god complex. Not even unicums have so much confidence they would change game on their own.

  7. it could work give it 2000 dmg ,low rof ( 1.08 ) and low range. Like fv 304 and high arc so it has to be close to the front line

  8. Newsflash, real shells don’t have damage values! Just because it’s 305 mm doesn’t necesarily mean it will have 3,000-4,000 damage and insane splash.

    For the sake of balance WG could just as easily give this mortar and even the Sturmtiger rockets damage values like what we allready have in the game. Plenty of guns around that has the same caliber but vastly different damage values for that reason allready in-game.

  9. And, of course, hits from a 305mm mortar would make some unicums cry, so that’s a bonus as well :)
    Words of a denying baddie.

  10. Storm made the claim that the Sturmtiger and its 380mm cannon were unbalanceble- if this were to make it into the game it would only prove what Ive said about every member of Wargaming being a lying, lazy sack of shit.

  11. If they put this 305mm gun in the game then there is absolutely no reason at all the SturmTiger can’t be put in the game.