Arjun Main Battle Tank (MBT) Mark II

[bhramos]

A collective weight reduction exercises for Arjun mk2 has been going on for the past 4 years overseen by IA's Director General of Mechanised involving the DRDO, MOD owned DPSU and private sector OEM. This will result in (if succeeded) a fully loaded 60 tonnes MBT armed with a 120 mm smooth bore cannon with an improved 1,400 hp powerplant.

DRDO developed 1500hp engine for Arjun MK2 tanks..

This is actually a 2000hp engine and will be tuned up for 1500hp for better and longer life..

 

[S.Balaji]

DRDO developed 1500hp engine for Arjun MK2 tanks..

This is actually a 2000hp engine and will be tuned up for 1500hp for better and longer life..

I was at the DRDO Expo conducted at CVRDE Chennai .....had an opportunity to speak to the people working on tank power packs...they said as far as Bharat pier pack s concerned only designing has been completed...prototyping not done....current status it is awaiting funding to bring in external consultant (probably MTU) to validate the design...they want to go safe, will go ahead only after validation of design...it s smaller in size than MTU power pack...so no problem in retro fitting while going for upgrades

 

[Kunal Biswas]

120mm smooth-bore is a requirement set for FMBT ..

A collective weight reduction exercises for Arjun mk2 has been going on for the past 4 years overseen by IA's Director General of Mechanised involving the DRDO, MOD owned DPSU and private sector OEM. This will result in (if succeeded) a fully loaded 60 tonnes MBT armed with a 120 mm smooth bore cannon with an improved 1,400 hp powerplant.

 

[Vijyes]

I was at the DRDO Expo conducted at CVRDE Chennai .....had an opportunity to speak to the people working on tank power packs...they said as far as Bharat pier pack s concerned only designing has been completed...prototyping not done....current status it is awaiting funding to bring in external consultant (probably MTU) to validate the design...they want to go safe, will go ahead only after validation of design...it s smaller in size than MTU power pack...so no problem in retro fitting while going for upgrades

Is it 1400HP or 1500HP or 2000HP? Did you ask about its horsepower?

 

[S.Balaji]

120mm smooth-bore is a requirement set for FMBT ..

CVRDE folks said 3 tonne has already been shaved off...weight reduction is still a work in progress...even the tank that was displayed for the DRDO expo last month was taken off of weight reduction trials..that tank was being tested for replacing the current 'electro hydraulic system' with an "All Electric Drive" which will reduce the weight of drive assembly by one-third...they had used ballast on the turret to compensate for the reduced waste during trials....the tank was displayed with ballast secured to its turret

 

[Kunal Biswas]

I have to say the CVRDE people are working hard to their core, Unfortunately the requirement set has no meaning due to the fact the bridges they are talking about cannot take weight of T-72M1 48 tons to Bhishma which is a 52 ton either ..

 

[Kchontha]

Since IA requirements are added on arjun mk1, which is already overweight to 61-62tonnes, the weight of Arjun mk2/mk1a spiral to a whopping 68-69tonnes that made the later heaviest mbt at present. Besides arjun cannot be airlifted to the himalayan region due to its weight which limits its deployable area to the north western sectors. For the arjun's weight reduction, for instance, the baseline hull is built with indigenous and lighter High Nitrogen Steel (HNS) in lieu of the imported Rolled Homogeneous Armour (RHA). As far as powerplant is concerned 1,400hp engine is retained since its industrial ecosystem already exists.

 

[Krusty]

I don't see why everyone is stressing so much HP figures for these engines and neglecting torque. For heavy machinery power (BHP) is not very meaningful as torque (Nm) is.

Quickly moving massive loads like that of a truck or tank you need loads of torque, power high or low doesn't matter very much.

Big Diesel engines by design are made to produce massive and immediate torque at Low RPMs at the expense of peak power. Petrol engines are opposite in philosophy.


Bhp rating might be good as a naming nomenclature, but it isn't a measure of the ability of the engine to move weights or its capability.

Can someone cite the torque figures for these eigines in the discussion please? How much torque is our own engine( in testing) producing as compared to the equivalent MTU or Ukrainian origin engines?

 

[Vijyes]

I don't see why everyone is stressing so much HP figures for these engines and neglecting torque. For heavy machinery power (BHP) is not very meaningful as torque (Nm) is.

Quickly moving massive loads like that of a truck or tank you need loads of torque, power high or low doesn't matter very much.

Big Diesel engines by design are made to produce massive and immediate torque at Low RPMs at the expense of peak power. Petrol engines are opposite in philosophy.

Can someone cite the torque figures for these eigines in the discussion please? How much torque is our own engine( in testing) producing as compared to the equivalent MTU or Ukrainian origin engines?

Power is converted to torque by gear mechanism. So, power is what matters

 

[Krusty]

Power is converted to torque by gear mechanism. So, power is what matters

Peak Power doesn't matter on heavy machinery. Torque does. Engines with Low power output but massive torque is what's required for these beasts. Are you talking about a torque converter?

If power alone was enough you have car engines having 1000+ bhp from tiny 3L to 8L capacity. Why aren't they being used? Because their torque output isn't nearly enough to even slightly budge a tank.

What is the reason then, that massive (turbo)diesels are preferred over petrol engine with very high power outputs for heavy machinery?

Forget heavy machinery, engines with high power aren't even preferred in off-road civilian vehicles. Because torque is more important While off-road. That is why even car manufacturers almost always go for diesels for off road vehicles inspite of having high powered petrol engines in their line up.


Here is a diesel Porsche towing a 285 tonne aircraft.

Do you think the same car with a high power petrol engine can do the same? What's the difference between them?

Come on.. seriously?

 

[Vijyes]

Peak Power doesn't matter on heavy machinery. Torque does. Engines with Low power output but massive torque is what's required for these beasts. Are you talking about a torque converter?

If power alone was enough you have car engines having 1000+ bhp from tiny 3L to 8L capacity. Why aren't they being used? Because their torque output isn't nearly enough to even slightly budge a tank.

What is the reason then, that massive (turbo)diesels are preferred over petrol engine with very high power outputs for heavy machinery?

Forget heavy machinery, engines with high power aren't even preferred in off-road civilian vehicles. Because torque is more important While off-road. That is why even car manufacturers almost always go for diesels for off road vehicles inspite of having high powered petrol engines in their line up.


Here is a diesel Porsche towing a 285 tonne aircraft.

View attachment 18792

Do you think the same car with a high power petrol engine can do the same? What's the difference between them?

Come on.. seriously?

Power can be converted to torque. A 1000RPM wheel if geared to give 10 RPM, its torque will increase. Power can be converted to speed or to torque. But that will need high end gears.

Diesel, by default has lower speed as diesel is a slow combustion fuel. You can't ignite a vessel full if diesel with a matchstick (try in your home if you don't believe). Petrol, on the other hand, is extremely fast combustible fuel and has higher speed by default.

Simply put, diesel engines provide high torque but low speeds compared to petrol engines which provide high speed but low torque for the same power. Petrol engines at high power can cause knocking as its speed becomes too high and the mechanical limits of engine comes in the way. Diesel engines on the other hand need heavy engines requiring high pressure tolerance and doesn't increase its speed too fast at higher power. Petrol engines are lightweight and can be used in low power situations with to provide reasonable speed of rotation but diesel engines get too slow at low power situations for practical use. But, at higher power requirements, petrol engines become too fast and diesel engines have the right speed and the right torque.

For example, consider a scooter and a bus. The speeds at which both travel are similar but bus has higher power than scooter. Lets say the scooter engine is 10HP while the bus engine is 200HP but both travel at same speed. Now, imagine getting a 200HP petrol engine that requires bus to travel at 10s of times the speed for same HP!

Diesel engines of slightly different specifications can be modified slightly to give different torque or speed by using gears. But the difference between petrol and diesel engines is so great that major gear modifications are needed which makes it impractical.

Second, diesel offers higher efficiency and mileage which is a big plus when it comes to heavy engine.

Third, diesel is lower quality fuel in terms of combustion which also means it is easier to make diesel than petrol. Even processes like coal liquefaction can be used to give diesel and kerosene while petrol is only 10% of the liquefied coal. Other processes like biodiesel can also be used. Even oil seeds can be used to substitute diesel in warm temperatures. Overall, diesel is a better fuel for our consumption and hence petrol substitution is not logical

 

[Krusty]

Power can be converted to torque. A 1000RPM wheel if geared to give 10 RPM, its torque will increase. Power can be converted to speed or to torque. But that will need high end gears

You aren't wrong. But that is hardly the point. And you never replied to any of my statements.


there is a limit to which you can convert. Nothing is free in nature. You cannot break the rules of mechanics and thermodynamics. You can keep gearing up but that will strain the engine resulting in rubbish performance.

To give you the benefit of doubt, Both these are gasoline engines producing 1500 and 1000 bhp respectively. Are you implying these can do the job on a tank with the help of converters? They won't even move the tank a few feet.. The engine will most likely explode.

A military vehicle needs to be robust and simple to take punishment and no be complicated to strain logistics and repairs. Why would you use converters when you don't need them? Take an engine that isn't suited for a task, add a component that you don't need to perform worse than a simple diesel?

I am starting to think you are arguing for arguments sake.

 

[Vijyes]

You aren't wrong. But that is hardly the point. And you never replied to any of my statements.


there is a limit to which you can convert. Nothing is free in nature. You cannot break the rules of mechanics and thermodynamics. You can keep gearing up but that will strain the engine resulting in rubbish performance.

View attachment 18798 View attachment 18799

To give you the benefit of doubt, Both these are gasoline engines producing 1500 and 1000 bhp respectively. Are you implying these can do the job on a tank with the help of converters? They won't even move the tank a few feet.. The engine will most likely explode.

A military vehicle needs to be robust and simple to take punishment and no be complicated to strain logistics and repairs. Why would you use converters when you don't need them? Take an engine that isn't suited for a task, add a component that you don't need to perform worse than a simple diesel?

I am starting to think you are arguing for arguments sake.

I have edited my previous comment. I posted it by writing little details initially as I had to go somewhere. But I got a chance to come back and hence edited my comment to make it more logical. But by the time I completed editing, you had posted another comment. Kindly take a look at my edited previous comment.

Next time onwards, I will not edit but instead post another comment as a follow on. My mistake for not knowing better

 

[Krusty]

I have edited my previous comment. I posted it by writing little details initially as I had to go somewhere. But I got a chance to come back and hence edited my comment to make it more logical. But by the time I completed editing, you had posted another comment. Kindly take a look at my edited previous comment.

Next time onwards, I will not edit but instead post another comment as a follow on. My mistake for not knowing better

You are missing the point, yes you can gear a wheel up or down but that will not affect to total power and torque output. Simple example is, you start a bike in first and fifth gear. That is effectively gearing up. It still doesn't change the power/torque charachteristics of the engine. Put in a bigger engine you get better results. You are missing the point completely. You are right about gears. But I am taking about the engine.

All, I apologise for derailing this thread. @Vijyes let's continue in the automotive thread about this.

Meanwhile, is appreciate it if someone posts the torque statistics.

 

[Vijyes]

You aren't wrong. But that is hardly the point. And you never replied to any of my statements.


there is a limit to which you can convert. Nothing is free in nature. You cannot break the rules of mechanics and thermodynamics. You can keep gearing up but that will strain the engine resulting in rubbish performance.

View attachment 18798 View attachment 18799

To give you the benefit of doubt, Both these are gasoline engines producing 1500 and 1000 bhp respectively. Are you implying these can do the job on a tank with the help of converters? They won't even move the tank a few feet.. The engine will most likely explode.

A military vehicle needs to be robust and simple to take punishment and no be complicated to strain logistics and repairs. Why would you use converters when you don't need them? Take an engine that isn't suited for a task, add a component that you don't need to perform worse than a simple diesel?

I am starting to think you are arguing for arguments sake.

I have also answered as to why one heavy diesel engine can be converted to other easily by minor modifications and hence the minor differences in torque which you are so emphasising may not matter much. It is definitely better to make exact torque speed balance than to put gears but that is something easily made, once the right power engine is obtained. Unless the engineers who made the engines are not fools, it is generally understood that tank engines will be made for the right torque and speed, with some spare capacity of 5-10% torque to provide for any weight increase. Tank speed can be sacrificed for the sake of torque. It matters little if a tank moves at 60kmph or 50kmph. But torque is more important for heavy vehicles to maneuver difficult terrains, weight change etc

 

[Krusty]

But torque is more important for heavy vehicles to maneuver difficult terrains, weight change etc

This was my point to begin with. It is there in my first post

 

[Vijyes]

Here is the RFI for the Bharat power pack engines as given in idrw website :

http://idrw.org/cvrde-invites-bids-development-supply-1500-hp-engine-power-arjun-mk-ii/

 

[Chinmoy]

@Vijyes & @Krusty ............. Something for both of you to discuss on other thread.

What is the difference between horsepower and torque?

http://www.badasscars.com/index.cfm/page/ptype=product/product_id=117/category_id=13/mode=prod/prd117.htm

BTW.... Don't forget to tag me along. :biggrin2:

 

[Krusty]

@Vijyes & @Krusty ............. Something for both of you to discuss on other thread.

What is the difference between horsepower and torque?

http://www.badasscars.com/index.cfm...ct_id=117/category_id=13/mode=prod/prd117.htm
http://www.badasscars.com/index.cfm/page/ptype=product/product_id=117/category_id=13/mode=prod/prd117.htm
BTW.... Don't forget to tag me along. :biggrin2:

Saar I am well aware of the difference between them and how they are related to each other. I was only trying to explain the design philosophies...

I just said in general heavy vehicles benefit from higher torque and lighter vehicles from higher peak power. Which is in my first post.

You can see where that led to..

 

[Chinmoy]

Saar I am well aware of the difference between them and how they are related to each other. I was only trying to explain the design philosophies...

I just said in general heavy vehicles benefit from higher torque and lighter vehicles from higher peak power. Which is in my first post.

You can see where that led to..

That's why I said "in other thread". But tag me along too if it is discussed.