Arjun Main Battle Tank (Mk-1 & Mk-2)

[RandomGoober]

No idea what's the current situation, they stopped publishing audits dealing with defence services. But it seems like they directly supply forged billets.

 

[Gautam]

Arjun Mk1 MBT:

 

[Gautam]

 

[Gautam]

DRDO's 120mm APFSDS Mk-2 round:

This one is said to have DOP of 530mm RHAe at 2 km range. The Mk-1 round had 300mm DOP.

SAMHO CLGM fired from an Arjun tank:

SAMHO has an 800 mm+ RHAe DOP.

 

[Fatalis]

https://twitter.com/x/status/1877998038192730414

 

[RandomGoober]

DRDO's 120mm APFSDS Mk-2 round:
View attachment 39569

This one is said to have DOP of 530mm RHAe at 2 km range. The Mk-1 round had 300mm DOP.

SAMHO CLGM fired from an Arjun tank:
View attachment 39568

SAMHO has an 800 mm+ RHAe DOP.

That's the 125mm one. The requirement is 530 with the caveat being "≥", in trials it has perforated a 275mm plate at 60° at 2km so about ~550. According to the EoI, such excess is to be considered an EPP (Enhanced Perfomance Parameter) for which the vendor will receive a credit score % and a credit factor for L1 determination costs.


Arjun's 120-Mk.2 is often shown against a 230mm target, sometimes at 63° (in the HEPF page which y'all know) and sometimes at 60° (some expo flyer) for the shot fired at 1550 m/s at a distance of 110-130 m with reduced charge, the next chart then said ≥515 against a 230 mm at 2 km


That 300 is the result of someone opening up the 150 mm at 60° which awfully sounds like a NATO Single Heavy target. If I remember the official requirement caps are where it "should" defeat a Single Heavy at 2500 m, a Double Heavy at 2200 m and a Triple Heavy at 1600 m if not more. But in an expo brochure it's advertised as defeating all targets in excess of 5000 m which just confirms that those aforementioned are bottom line.


In reality, the rod measures approx 385-400×29 mm so perforation should be about 400 or more imo, penetration is 350-370 mm in latest DRDO sources.


By the way, perforation is used for finite target and penetration is used for semi-infinite target, the former will always be more than the latter.

 

[RandomGoober]

CVRDE has put out a tender for fabricating a new tank chassis for testing purposes. There are 2 tanks in development currently; the NG-MBT & the DRDO/L&T Light Tank :

The chassis is supposed to be fabricated by a private company. The pvt. company is likely L&T Defence. The program is divided into 3 milestones, the program will conclude with in 18 months from the date of issue of contract. Here is a summary of items that need to be delivered in all 3 milestones :
View attachment 21293
Now lets get into the details of the work in every milestone. Starting with Milestone 1:

View attachment 21290

Milestone 2:
View attachment 21291
Milestone 3:
View attachment 21294
In Milestone 2 you can see a lot of switches, plugs, relays, connectors etc. being purchased from two German companies: MTU & RENK. These 2 companies supply the engine & transmission for the Arjun Mk-1/1A tanks. The Arjun is powered by the MTU MB 838 Ka-501 V10 liquid-cooled turbocharged diesel engine producing 1400 hp coupled with a RENK supplied epicyclic gear box.

The K9 Vajra used the MTU MT 881 Ka-500 V8 water-cooled diesel engine producing 1000 hp coupled with an Allison X1100-5A3 cross-drive transmission.
View attachment 21296
So if this new chassis is getting the same engine/transmission set up as the Arjun this must be the NG-MBT right ? But in Milestone 1 you can see CVRDE wants 22 tons of SPADE 500 steel Medium Hardness Armour (MHA) plates to be supplied. But the NG-MBT was supposed to use High Nitrogen Steel (HNS) as the non-reactive armour. That was also one of the reasons why you needed the new 1500 hp engine to get a high power to weight ratio.

It seems they are going for downgraded armour & are getting an off-the-shelf engine for the NG-MBT. Almost like they want to get the tank rolling ASAP & make incremental improvements later. Maybe the MoD told them to hurry up.

The estimated weight of the NG-MBT was 41 tons. With the MHA that should reduce down to 36-37 tons. If they remove the ERA for high altitude operations the weight can be less than 35 tons. Maybe this is the new light tank they are going for now.

There has been news reports of the light tank based on the K9's chassis being dropped. The tender also says CVRDE will provide the engineering drawings of the chassis to the selected company. If it was the K9 chassis what drawing would CVRDE provide ? They don't own the IP for that chassis, the Koreans do.
View attachment 21295
The 58 ton Arjun Mk-1 with a 1400 hp engine has a power to weight ratio of 24 hp/ton where as the K9 is at 21.3 hp/ton. The 41 ton NG-MBT with the 1400 hp engine would be at 34.15 hp/ton. If they can reduce the weight to 35 tons then it would be 40 hp/ton. This combined with the Arjun's 120 mm rifled gun would make it a potent tank.

The TATA/DRDO Kestrel/WhAP weighs 25 tons & has a power to weight ratio of 24 hp/ton. The WhAP has been deployed in Ladakh. Maybe we should try to get a 105 mm on this along with the new 700 hp engine. An upgraded WhAP & a light tank working with the T-72s would be a significant capability boost up North.

We will need to find lighter armoured vehicles for amphibious ops in the future. The 43 ton T-72 aren't a great option for beach landing. May be this tank can eventually replace the 1900+ T-72 tanks of the Army.

CVRDE has also released a tender for manufacturing their in-house designed Low Voltage Displacement Transducer (LVDT) for powering the tank's systems:
View attachment 21292

Hello, I know this is a bit late (like 4 years lol), but would you still have that complete tender document for the test chassis?

 

[Gautam]

Hello, I know this is a bit late (like 4 years lol), but would you still have that complete tender document for the test chassis?

Some old links have gone dead. But I have this:

 

[RandomGoober]

Some old links have gone dead. But I have this:

Thanks, if this tender was awarded, then it should have been completed somewhere around 2023 (T0+18 with others being inclusive). Was just tryna look around recent CVRDE visit pics to spot something different lol, btw I think it could only be the NGMBT since FICV/AAP is a VRDE project.

Also would you know if Defence PRO handles like the one in Chennai release videos of the visits? Just had a hunch and wanted to see that hull at the last in full, might as well just be some trivial disassembly of something ordinary, but still.

https://twitter.com/x/status/1879501870743560200

 

[Gautam]

Also would you know if Defence PRO handles like the one in Chennai release videos of the visits?

Don't think so.

Just had a hunch and wanted to see that hull at the last in full, might as well just be some trivial disassembly of something ordinary, but still.

That looks like a disassembled Arjun tank chassis.