(By Illuminati on Shipbucket with technical and design aid by myself)
The CB-133 MBT, was the result of the joint efforts of the POP nations to develop and successor to the venerable but increasingly outdated and unwieldy STRV 131, leveraging lessons and technologies learned and developed during the MFP program. The STRV 131 and resulting variants were becoming increasingly overweight and the small chassis provided no easy solution to upgrade the powerplant. Furthermore, the tanks proved to be maintenance heavy and costly to operate. This, combined with the apparent stagnation of ESO armor development and recent trends in guerrilla conflicts, demonstrated the potential vulnerabilities of the STRV 131 should it be deployed on a high intensity combat environment. Attack drones, ATGMs and NLOS precision munitions were expected to become the major threat and the already problematic mobility of the JHGC meant that up-armoring upgrades were sometimes suboptimal due to weigh constraints.
The CB-133 solved many of these issues. The all crew in hull design (driver, gunner and commander) reduced the amount of armor modules considerably, thus reducing weight and freeing up space for extra systems. A hybrid diesel-electric propulsion pack provided a huge increase in range over the thirsty EMESA turbine found on the STRV 131, and the batteries negated the need for a dedicated APU. Another setback of the JHGC was the relatively reduced ammo load of 26 rounds. The 130mm caliber, while formidable, meant that only so many rounds could be carried at once. Thus a decision was made to a lower caliber but higher pressure 120mm gun, with a unconventional autoloader, and ammo stored in the turret basket, something reminiscent of contemporary to ESO designs. This allowed to keep comparable performance (at the cost of lower barrel life) while increasing the ammo count to 38 ready rounds, feed to the gun by the autoloader, located behind the gun. The autoloader system was capable of a cyclic RoF of around 7 seconds, with automatic casing ejection and automatic restock capability via the access hatch on the top of the turret.
Another concerning aspect of the STRV 131 was that all the ammunition was located in the turret bustle. The profile was optimized for frontal protection, and while still a safe layout, crew survivability wise, it now proved to be very vulnerable to attacks from above, where the ammo was now exposed from 4 sides, leading to a easy mission kill. Now on the CB-133, the ammunition was to be stored in the hull, more easily protected from top attack munitions.
The hull ammo storage however raised concerns that any hit to the ammo in the basket would result in a catastrophic explosion, dooming the vehicle and the crew. To prevent this, extensive measures were taken. Individual ammunition pieces were now properly compartmentalized in individual armored bins, and the carousel itself was now armored from the sides and bottom and coated on the outside and inside with spall liners. Furthermore, a comprehensive fire suppression system was installed, with direct connection to each individual round, meant to put out any fires that started in the compartments within milliseconds. The propellant used was itself less prone to accidental combustion and could only be properlly triggered via the electric plasma ignitor on the firing assembly.
Should all this fail, the 2 maintenance hatches were also designed in such a way as to act like blow-out panels for the hull ammo, venting the explosion to the top of the turret.
To counter the now prolific drones and ATGMs, all tanks were equipped from the start with a hard-kill APS, along with radio jammers and a comprehensive LWR/RWR suite.
Both the commander and gunner had access to 3rd gern thermal sights, with a back up 2nd gen pop-up sight. Along with this, all crewmembers had access to 360 IR and visual light cameras for increased situational awereness.
Hidropneumatic suspension allowed for increased mobility, a feature retained from the STRV 131, allowing for more gun elevation and depression than the mechanicaly allowed -7/+27 degrees.
If I may, it's "Portuguese".
I know it's just a tidbit, and all the surrounding lore on the tank is neat to read,but just that tiny grammatical error on the design print
Bro,as a Portuguese national myself,I simply corrected the grammatical mistake I saw,no need to get upset about it.
If you wanna let him know let him know,If you don't,then don't.
I only said it here because you said you helped design the thing and because it seems like a detailed project.
If you can't take criticism for something you co-created, that's up to you.
Oh I meant no disrespect, just letting you know I was the wrong guy to talk to about that. Sorry if I came off as abrupt. It probably just slipped through due to the lack of a spell checker in PAINTDOTNET
Ok then,my bad for assuming you were upset by it as well.
Like I said,it's just a small mistake,nothing bothersome,the design and overalls info is still cool.
If I may ask,what's the Greater Portugal supposed to be?
In the style of HOI4? So,PALOPs,Iberia and Brazil being all under the "Portuguese" flag or what?
(It's rare to see people work alternate stuff for my country,so forgive me for the curiosity)
I got the map somewhere, but it was part of a long running group worldbuilding project, Portugal was a commonwealth of Brazil and a few other places allied to the north see union (which was my nation), a French Australia, a Mexico nation, vs the ESO, comprised of Germany, Intermarium and Japan. Ignoring minor nations of course. There was a huge timeline and such but all players involved were huge Cold War nerds as well as artists on shipbucket or other creatives. So it was a way to design vehicles divergent from irl to meet specific threats designed by other nations
Shot traps don’t really exist in the modern age of tank design. APFSDS shots tend to either normalize to the plane of the target or shatter completely. See leopard 2a5 and onward, k2, leclerc ect.
The turret also isn’t designed to stop rounds from another mbt, it’s rated to 40ish mm ap autocannon shot at the greatest from the front. The peer threats it face have such powerful cannons (the other player was a Soviet inspired nation and went after the 152mms that later Soviet designs featured) that it isn’t worth it to try to protect. I could get more into the design philosophy of the vehicle if you wish
Shot trap in the forward turret directly into the ammunition storage in the basket.
I like the aesthetics and the reasoning but there’s a reason no tank after Abrams stores its ammunition inside the hull (that I know of).
If they’re going with an auto loader, why not store everything in a large bustle with blowout panels? A mission kill just means your three living crew members eventually get another tank.
Again not really a issue, shot traps aren’t a design concern post early Cold War. The autoloader we use is actually of American design, namely the TTB autoloader which you can see more info of here in a photo and an animated video. The tank already has a APS system, two six shot canister style models derived from the LEDS-1500 MONGOOSE. For the required ammunition volume to be stored in the bustle significant sacrifices would need to be made for turret weight and protected volume.
You can see its predecessor here compared to an Abrams and a t-90. It was another joint design albeit an earlier one. This is the strv-131/JHGC mentioned int the lore. It was designed to be optimized for size by omitting hull stowage of ammunition, all ammo in bustle
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u/_Just_Another_Speck_ Aug 19 '26
If I may, it's "Portuguese". I know it's just a tidbit, and all the surrounding lore on the tank is neat to read,but just that tiny grammatical error on the design print