Design your own tank

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Pratyush
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Re: Design your own tank

Postby Pratyush » 14 Dec 2010 16:10

Singha wrote:troops on extended patrol in afghanistan are having trouble carrying enough batteries to power their NVG , radios and rugged laptops. the energy storage of batteries doesnt look so hot at this point. but Fujitsu was experimenting with a fuel cell battery for laptops...maybe you can read up on that see if anything promising via fuel cells.


They can simply carry a backpack solar panel to charge the gizmos. IIRC IA in siachin uses some thing similar to recharge the Radio battries. Weighs arround 7 KG.

At least thats what I remembed form the newj reports. of the early 90s............

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Re: Design your own tank

Postby jamwal » 14 Dec 2010 16:56

This thread was originally started to discuss the design of a Main Battle Tank for Indian army. Most of the suggestions till now have been for anything but a MBT. As per my limited understanding, nothing can replace a heavily armoured battle tank in a battle field. Jeep mounted RCLs, NAMICA, ATGMs are all good, but at best they provide only a defence against enemy tanks. They are not offensive weapons.
Further, none of the above carry a machine gun. I don't think tanks are as useful without a machine gun in urban combat as well as infantry supporting roles.

Why not keep the discussions limited to technologies that can be mass produced within next 2 or max 3 decades ?

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Re: Design your own tank

Postby shiv » 14 Dec 2010 17:19

manish.rastogi wrote:for your question i honestly don't know any names.....i have just seen on internet that there are buses and planes etc already in use with this current tech!!
Now i am not sure whether the technology is ready or not as i don't know the current status and the sophistication of this tech......
If its ready then all good......if not i seriously think that we should build upon the available technology!!
My guess would be that with decent budget it is achievable in a 5 -6 year time frame!!or else 3-4 if we do it in partnership with some european or american firm which are pretty ahead in this tech from us!!!


Well let me ask you to use the internet to search for who has produced a vehicle (say a bus) using this tech, where it is in use, and why it is not in use if it is not. What are the weights of the fuel cells. Life. Range etc. Its one thing to have general information - all of us know lot of general stuff - even without doing a Google I can tell you the name of the only electric plane to have flown. But I can't tell you offhand its weight and range. And the manufacturer or details of power source. I would have to do some digging for that. Why don't you do the digging and educate us? You will learn as your education progress that research and experimentation is all about collecting all known facts first.

Let me also tell you something that you may be learning about at your age. Do you know what percentage of energy from an internal combustion engine actually goes towards running a vehicle? Would it be 100%? 50%? 25%? 10%? That as you may know is the energy efficiency of an engine.

Now the big disadvantage of creating electricity from a generator is that a generator is also an engine like a car (or tank) engine and it has a particular efficiency (Google for the actual figure. You will be surprised if you don't already know).

When you use petrol or diesel to move a car - the chemical energy stored in petrol is converted to mechanical energy to drive the car. You are losing energy in conversion and then you are losing some more energy as friction. The "useful process" that we want here is:

chemical energy (petrol) becomes mechanical energy and drives the tank

But when you recharge a battery the process is:

chemical energy (petrol) becomes mechanical energy to drive the generator to produce electricity to charge a battery (energy stored again as chemical energy) which will then be used to produce electricity converted by a motor mechanical energy to move the tank

When you use chemical energy to recharge a battery you are still losing the same amount of energy in the engine - but you are now not using the energy to move a car/tank - you are just storing up that energy as a new type of chemical energy in a battery. After that the battery will supply its energy to the tank or car and some of that energy will be lost in the efficiency of the motor and in friction.

I am not sure if you understood what I meant by "two step process". You are burning the same fuel but introducing more steps in the process of producing stored battery energy. No matter how efficient your electric motor may be, you are already losing energy just in the process of charging. All 100% of the energy will not get stored in the battery, Some gets lost during conversion. And since the original energy source is the same in both cases (Fuel oil/petrol/diesel) the two step process is more wasteful even if electric motors are more efficient. That means you use up more fuel for charging batteries than you would use for just running the existing diesel driven vehicle. That not only raises costs but it also raises the extra logistical problem of transporting larger volumes of fuel to an area near the battle zone.

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Re: Design your own tank

Postby shiv » 14 Dec 2010 17:41

I would like to add another point about battery power/fuel cells in a hypothetical war in Aksai Chin in which Indian forces have advanced say 25 k.m. on day 1. Now the frontline is 25 km away from the starting point that had all the food, water and fuel or generators.

How do you supply the frontline 25 km away? You can send food, water and ammunition. If your tanks/trucks are running on diesel - you can send diesel.

But if they run on batteries what do you do? Do you ask your forces to withdraw and come home for a recharge? Do you send fresh batteries up? Or do you send a mobile recharging station to stay near the front? Diesel refuelling takes 10 minutes per vehicle. How long does a recharge take? How many vehicles can be recharged at a time? If recharging takes even 2 hours that's too long. So do you send trucks full of spare charged batteries to the front? The loss of 2 or 3 fuel laden trucks can be borne. But can the loss of two or three recharge(generator) vehicles be borne easily? They will be high value targets

I like the general idea of civilian use of electric vehicles. But a whole lot of questions need to be answered if one talks of use in war - especially armored vehicles that may form the cutting edge of offence or defence- essentially a life or death situation.

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Re: Design your own tank

Postby manish.rastogi » 14 Dec 2010 18:11

Okay so here it goes bear with me......
Role and philosophy
I envisage it as a main battle tank.....but its time frame could be said as 2022-2023!!Highly network centric with super sophisticated software!!!Highly mobile....and agressive!!

Specs and Weapons
i know it sounds weird but the design should be aerodynamic!!Not like a rocket or something but should take advantage of aerodynamics all the while still being masculine looking!!!
Now it would have 3 persons....one commander,one driver,one for weapons and all!!
Now the commander and driver would have some sort of display helmet like for fighter pilots but highly customized!!
The commander's helmet would have a secure small distance connection with a control panel like that of a keyboard or something for his work!!!The commander should be able to see infrared thermal emission etc on his display which also would track his eyes....he could assign priority targets and diff targets in a line!!he could customize the software for himself.....the tank would just tag the targets which would be in line and keep tracking them....and start firing while the commander is busy doing other work!!Also a system should be there so that whatever data the radar gathers a basic picture could be created of mountains vehicles personnel's on the basis of thermal etc....and a bird eye view of the battlefield could be created for a radius of whatever seems appropriate!!
The driver's helmet would not have targeting features but rest could be same with some more features to aid in driving!!
The weapon guy just would select which kinda weapon to be hit to which vehicle and all and any other work which i don't know :P !!
Weapons
Main Gun
i am taking out the main gun....i somewhere read that it could weight upto 15t....i don't want that.instead i propose a cannon kinda system in 4 direction or maybe 3 directions covering 360 degree....also they should be able to have an angle of around 15 to 75-80 degree in vertical, it should be able to make a cone with its movement....i am talking about each cannon....and the whole system of those 4 should be able to rotate 360!!(sounds complicated but is realistic)....this would lead to good weight reduction.....i think the cannons could be somewhat longer than a normal 120 mm mortar....should be made totally of titanium and composite!!!having a range of >current tank main guns....
Secondary weapons
There should be custom built modules of 3 Nags on each side which could be added as and when necessary.......
Two AA guns also in modules placed diagonally for maximum coverage....(i need suggestions in this one) also the cannon could be used for the same purpose too!!!(We could even have 1 Nag and 1 AA module)
1 12.7mm machine gun with a add on grenade launcher system.
1-2 7.62mm machine guns at appropriate positions!!(if 2 then atleast 1 should be operable by computers!!)......
Now on every side of the tank i need a mechanism not much in size 8-9x8-9x14-15 in box type which could carry 4-6 small missile type with ICL-20 as their ordinance for bigger bang in small package for its own protection as well as for targeting less armored vehicles....it should be able to reloaded from inside the tank!!
Protection would always come first if the tank detects an incoming hostile weapon towards it....it could stop shooting the given targets and shoot the incoming threat with every possible way!!..........umm i cant think of anything else now
Then there should be Smoke grenade launchers
Active Jammers
and other things which i don't really know a lot about.....(feel free to add)

Armour
Very imp....also very weight intensive!!
In the middle part i dont think heavy armour is needed as only bullet protection is generally needed there.....most of the weapons target from top!!!(Not sure about this one) :roll:
Now i guess we should have average armor mostly some new kinda composite created inhouse.....as i would like to concentrate more on protection through the protection systems!!!
But still the composite armor should be decent!!!
And the rest of things would be general only.....
please do add your suggestions or additional features you would like!!...

Engine
As said in my previous posts fully electrical engines......

Weight
For this lets say its weight would be around 35-40t(just a guess)

Finally it could be a total in house project but some help could be taken from american and Europeans in technological stuff related to it and electrical things to reduce development time!!!

Now,if you have read all this THANKS....for bearing.....it got quite long!!!
Please do constructive criticism and do give additional ideas.....would like to refine it as much as possible!!!

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Re: Design your own tank

Postby manish.rastogi » 14 Dec 2010 18:20

Shiv Sir......i read all your posts and i have tried to understand them as much possible as i can......
Now i would like a favor, with your barrage of questions i got confused....could you please arrange the questions and post again....so that i could answer them easily and properly...!!!
Many thanks....

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Re: Design your own tank

Postby prabhug » 14 Dec 2010 18:28

My understanding of fuel cells is that , the scientists ultimate aim is to separate hydrogen from water to use it(hydrogen) as fuel.What we need to carry is only the agent to convert water into hydrogen.I don't thing the technology is so matured to do it.

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Re: Design your own tank

Postby prabhug » 14 Dec 2010 18:39

i had following thoughts , may be something available now

1.Data link among the tanks/to centre location
2.Miniature weapon locating radar
3.Dedicated UAV's UAV connection for fire correction and damage assesment.
4.Inertial guided rounds for accuracy (GPS might be costly we have to find some corrective action based on the gun, like zeroing the guns)
5.Modular protection (Kind of protection which can be added/removed in hours.The Aim is to team decide it based on terrain
6.Offcourse IR reduction using good diesel engine exhaust
7.Something like automatic Flare dispenser for cheating 3rd gen ATGMs would be ultimate

Cheers

Prabhu.G

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Re: Design your own tank

Postby negi » 14 Dec 2010 18:47

Fuel cells or other forms of batteries require sufficient cooling and heat dissipation measures in order to work reliably and safely.

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Re: Design your own tank

Postby abhik » 14 Dec 2010 19:07

Also generally the energy storage capacity of a battery rapidly reduces with a fall in temperature, in fact an electric car co.(Tesla) found that it is simply more efficient it battery use up some of its stored energy to heat itself continuously rather than just let its temperature drop to a lower ambient temperature.

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Re: Design your own tank

Postby Rahul Mehta » 14 Dec 2010 19:10

Attn : Shiv

If possible, pls email me at MehtaRahulC@yahoo.com

====

Admins,

Pls delete this past after two days

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Re: Design your own tank

Postby Pratyush » 14 Dec 2010 19:16

self deleted
Last edited by Pratyush on 14 Dec 2010 21:18, edited 1 time in total.

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Re: Design your own tank

Postby vijyeta » 14 Dec 2010 19:51

prabhug wrote:My understanding of fuel cells is that , the scientists ultimate aim is to separate hydrogen from water to use it(hydrogen) as fuel.What we need to carry is only the agent to convert water into hydrogen.I don't thing the technology is so matured to do it.


It's called Electrolysis. Theoretically, all you need is a mobile electrolysis unit to split water to Hydrogen.

Again, there are two options while using Hydrogen as a fuel - One is the fuel cell/battery approach. The other is to actually burn H2 in an internal combustion engine.

I don't think the battery/fuel cell approach is feasible for combat. The second idea can be explored, and maybe that is is what DRDO is thinking about.
Let's not assume fuel cells......

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Re: Design your own tank

Postby Virupaksha » 14 Dec 2010 20:23

manish.rastogi wrote:Shiv Sir......i read all your posts and i have tried to understand them as much possible as i can......
Now i would like a favor, with your barrage of questions i got confused....could you please arrange the questions and post again....so that i could answer them easily and properly...!!!
Many thanks....


Manish,

Electric vehicle is a tag, just as hybrid/nuclear/fuel cells are. Forget the technology to be used. The improvement for a new engine compared to a old engine should be
i) improved or simplified logistics
ii) simplicity to repair and maintain
iii) decrease in reload time
iv) cost
v) reduced weight /increased bhp/ reduced size
vi) if possible reduced noise
etc

Things which should not change
i) safety
etc

ii and iii are interchangeable, iv and v are interchangeable according to perception. the rest of the improvements are in decreasing order of importance. The electric engine is sacrificing i, ii, iii (mostly even iv) for v and vi.

Instead of first fixing on a technology, first list out your priorities or requirements, then depending on the requirements choose your technology. If the priority order changes, then technology may/should also change.

electric engine is a marketing tag. Technologies come and go, but it is your requirements which count.

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Re: Design your own tank

Postby manish.rastogi » 14 Dec 2010 20:48

^^^ i don't understand how (i) is sacrificed here...taking in general....i think somewhat less fuel would be used than the regular needed....
(ii)....for this all you need is some training to personnels and you are done...
(iii).....here i totally agree that this is getting sacrificed....
about (iv) i am not sure.....

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Re: Design your own tank

Postby manish.rastogi » 14 Dec 2010 20:56

Guys....to my knowledge fuel cells are not limited to just Hydrogen......there is more to it!!!

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Re: Design your own tank

Postby shiv » 14 Dec 2010 21:02

prabhug wrote:My understanding of fuel cells is that , the scientists ultimate aim is to separate hydrogen from water to use it(hydrogen) as fuel.What we need to carry is only the agent to convert water into hydrogen.I don't thing the technology is so matured to do it.


Water is a very very stable compound because the hydrogen and oxygen of H20 simply love each other so much that they remain in a tight embrace. You need to put in a lot of energy to break their pyar ka bandhan (bond of love).

So no matter what agent you use, that energy to break water has to come from somewhere and a lot of energy is required. Once it is broken down this stupid Hydrogen thing acts like a complete idiot. The molecules are so small that they escape through the smallest pores. It is so reactive that it will react with all sorts of materials. And if oxygen is nearby it will immediately cancel its talaq from oxygen give up all the energy you have put in and produce a bang. Storing that hydrogen in stable form and in large enough amounts is the big problem currently.

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Re: Design your own tank

Postby shiv » 14 Dec 2010 21:03

Rahul Mehta. Done.

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Re: Design your own tank

Postby aniket » 14 Dec 2010 22:13

i am a beginner so pls correct any mistake.
i think that we should design a tank based on the bhishma but it should feature a separate compartment for the crew, heavier armament a hybrid armour with something like a tusk kit for urban combat and should have a gas turbine as it has many advantages already highlighted earlier.
also we should learn from the israelis like how they made an icv out of captured enemy tanks.

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Re: Design your own tank

Postby Virupaksha » 14 Dec 2010 22:31

manish.rastogi wrote:^^^ i don't understand how (i) is sacrificed here...taking in general....i think somewhat less fuel would be used than the regular needed....
(ii)....for this all you need is some training to personnels and you are done...
(iii).....here i totally agree that this is getting sacrificed....
about (iv) i am not sure.....

manish,

less/ more is only one part of the equation.

Imagine you are a taxi operator. and you have 10 cars and buses, which you have to refuel say every day. Now all these cars are being taken to say a desert for a month long trip, say thar/sahara tourism where there is no pumps anywhere. So you have 1 truck to carry only fuel, which does trips only weekly. normal case for army.

Case 1: 50% more fuel efficient cars but differently fueled.
1 car runs only on normal petrol, other on diesel, another only on speed 91, other only on hybrid fuel, another on battery liquids

Case 2: less fuel efficient but all running on one fuel

What would you as a taxi owner or the logistics officer like?

I will definitely vote for case 2. In case 1, if I miscalculated a tiny low percentage of one fuel in the 10 fuels or 1 particular car had to drive more than normal, that car is stuck (and for the army it is the whole tank fleet), so the entire convoy just sits around doing nothing.

Now, the logistics officer has already to worry about food, different types of weapons, spares, different ammunition, different types of vehicles, their spares, their fuel etc.

The best tank/engine in the world is useless unless he gets the ammunition, fuel, spares.

The range of a weapon is only the range until which its logistics can support it.

The range of a airplane, say F-18 is 1500 km. But it is deployed 15000 km away from its homebase, which is the range of logistics. So the actual range of F-18 is 16500 km.

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Re: Design your own tank

Postby bapatnikhil » 14 Dec 2010 22:39

No offence but it sounds to me like you are all arguing without knowing how fuel cells work.

Fuels cells i.e. batteries of fuel cells are charged using Hydrogen gas. So a vehicle using fuel cells is charged the same way a vehicle using Patrol/Diesel is 'charged'. Simply fill the tank with hydrogen which, incidentally, is faster thank liquid charging. Fuel Cells are not charged by passing a current in reverse direction which takes time. Now there are two basic types of fuel cells: Low temperature fuel cells using Hydrogen as fuel and Oxygen from atmospheric air and high temperature fuel cells using hydrocarbons (our normal fuels) as fuel to generate electricity. The high temperature fuel cells are still under development.

Hydrogen fuel cells is a mature technology ready for mass implementation. So to fit it in a tank is just a question of making a bigger fuel cells. The major problem with it is the storage and transportation of Hydrogen on a mass scale. There is simply no infrastructure in place that would generate and transport enough hydrogen for Fuel Cell Vehicles. Hydrogen is very expensive right now (twice the Diesel on weight per weight basis). Secondly Hydrogen is not prepared/manufactured from water electrolysis. It is manufactured from fossil fuels by reaction with steam. Water electrolysis is one of the methods but it is suitable only if we can use renewable energy like solar/wind or nuclear. Because right now almost 70% of our energy comes from thermal and if you see the energy balance equation for the electrolysis, generation of hydrogen, though possible on small scale for chemical plants, is not possible for generation of hydrogen as a fuel.

So here are the similarities and differences between a normal fossil fuel and fuel cell system in urban scenario:
Get fossil fuel from somewhere which is basis for both technologies right now.
Fossil Fuel Refineries = hydrogen generation plants
Bharat Petroleum Supply Chain = hydrogen pipelines
Petrol Pump in Mumbai = Hydrogen Pump in Mumbai
My Bajaj Pulsar = Honda FCX
The problem is that the things on right side of the equations do not exist is sufficient numbers.

So the pros and cons I thought about using fuel cells in Tanks:
If only tanks run on fuel cells logistics will have to carry Diesel for all vehicles and Hydrogen for tanks. (This will not be a problem with High Temperature fuel cells which use fossil fuels). No problem if all vehicles use fuel cells: this requires a lot of transformations.

Fuel cells are twice as efficient as IC engines. So a tank that can go around 300 km once filled, can go around at least 500 km with fuel cells.

As I said before, the only thing in the way of fuel cells technology is that the infrastructure required to generate and transport Hydrogen to every corner of the world simply does not exist. If high temperature fuel cells become operational on significant scale, then this problem will also be solved. The supply chain for Petrol/Diesel/CNG/LPG already exists everywhere.

As for hydrogen supply; there are several ways to solve this problem.
1)Have large Hydrogen Plants in a few locations and transport pure hydrogen via pipelines and tankers to local Hydrogen Pumps. The advantage is that very pure hydrogen, which is critical for fuel cells can be used.
2) have hydrogen generation plants at intermediate state for example instead of having only one huge plant supplying fuel to say Mumbai, Pune and Nasik, we can have three smaller plants each one for one city and then the fuel is transported to Hydrogen Pumps. Here also we maintain the purity of hydrogen, simplify transportation but cost of setting up 3 smaller plants is more than one huge plant.
3) Convert it at Hydrogen Pumps. The technology exists for this small scale conversion at each individual nodes but there purity of hydrogen is the issue. The main advantage of the third is that existing infrastructure for transportation and distribution of fossil fuels is used and hydrogen is generated as and when required.

In my opinion, the third is best suited for civilian while for our purpose second option looks best. The intermediate stations would be closer to areas operations but sufficiently inland to protect from enemy. Fossil fuels will be delivered to these stations conventionally and Hydrogen generated would be supplied to troops in that area using existing logistics chain, albeit using different equipment.

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Re: Design your own tank

Postby Virupaksha » 14 Dec 2010 23:10

bapatnikhil wrote:No offence but it sounds to me like you are all arguing without knowing how fuel cells work.

So back to the basics are we? I dont care how fuel cells work. Unless it uses djinn powers, it needs refuelling and so bam, logistics.

Let me list out the problems from your own post
i) So to fit it in a tank is just a question of making a bigger fuel cells.
-basically means not yet mass production ready
ii) The major problem with it is the storage and transportation of Hydrogen on a mass scale. There is simply no infrastructure in place that would generate and transport enough hydrogen for Fuel Cell Vehicles.
- a complete new logistical chain required
iii) Hydrogen is very expensive right now (twice the Diesel on weight per weight basis).
- cost is a bummer
iv) The problem is that the things on right side of the equations do not exist is sufficient numbers.
no mass production, therefore no leverage over existing logistic chain
v) If only tanks run on fuel cells logistics will have to carry Diesel for all vehicles and Hydrogen for tanks. (This will not be a problem with High Temperature fuel cells which use fossil fuels).
-Note: Fossil fuels is too broad a term. If one car uses petrol, other car diesel and somebody says both are fossil fuels :wink:
vi) No problem if all vehicles use fuel cells: this requires a lot of transformations.
- will only work if you disband the entire army one day and create a new one
vii) Fuel cells are twice as efficient as IC engines.
- and all this for a mere 50% increase in efficiency
As for hydrogen supply; there are several ways to solve this problem.
1)Have large Hydrogen Plants in a few locations and transport pure hydrogen via pipelines and tankers to local Hydrogen Pumps. The advantage is that very pure hydrogen, which is critical for fuel cells can be used.
2) have hydrogen generation plants at intermediate state for example instead of having only one huge plant supplying fuel to say Mumbai, Pune and Nasik, we can have three smaller plants each one for one city and then the fuel is transported to Hydrogen Pumps. Here also we maintain the purity of hydrogen, simplify transportation but cost of setting up 3 smaller plants is more than one huge plant.
3) Convert it at Hydrogen Pumps. The technology exists for this small scale conversion at each individual nodes but there purity of hydrogen is the issue. The main advantage of the third is that existing infrastructure for transportation and distribution of fossil fuels is used and hydrogen is generated as and when required.

so basically instead of leveraging civilian infrastructure, army will have to build its own infrastructure. :rotfl:

and what of the increase safety features required for hydrogen handling?

From your own post, I can see that you have not claimed cost, logistical, maintainence, non-complexity benefits :lol: Now again why should the IA move to fuel cells?

Al-gore and their minions marketing successes astonish me

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Re: Design your own tank

Postby abhik » 14 Dec 2010 23:49

now that Singha saar has sent in his drawing I couldn't resist,
(please note the image is pretty huge and the text is small so you'l have to zoom in and out(may test your patience!), also its been through a couple of conversions so its somewhat faded out.)
Image
Its some what conventional with front engine, 2 man crew, remotely controlled turret, with armor only where and when it is needed. I'm quite sure something like this can be achieved at a weight of 25t-30t, which will make it air transportable by Gagaraj and c-17s. One could also imagine an autonomous/remote controlled version.
More on it later.

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Re: Design your own tank

Postby arunsrinivasan » 14 Dec 2010 23:56

re. electric engine, since the key problem is the power source i.e. battery / fuel cell. Can a diesel-electric engine be adapted for a tank? What are the pros & cons? It is a mature technology & diesel fuel means there wont be logistic problems. I tried unkal google, & got info on its use in locomotives, but could not figure out if there is a weight penalty compared with a diesel engine and or if there is any efficiency advantage.

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Re: Design your own tank

Postby manish.rastogi » 15 Dec 2010 00:14

thanks bapatnikhil really needed that.....what about those vehicles which plug into power source and they are ready to go...!???

Ravi sir i never said we gotta use it now its definately gonna take 7-8 years to develop so basically the problem of mass production seems solvable in that time frame.....also a 50% efficiency increase is not mere its pretty huge....!!!even if it increases range from 300 to some 400-450....i am happy....also maybe if we do research we could get high temperature level fuel cells tech matured!!

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Re: Design your own tank

Postby Gurneesh » 15 Dec 2010 01:37

When talking of Hydrogen, all looks very rosy until one considers the practical aspects involved with using it. H2 is very light, thus to get any meaningful power output one needs a high volume flow rate. Now this may not be a big problem is H2 is being produced in-situ and used immediately. But if we want to produce H2 somewhere else, then transport it and store in a gas tank a number or practical problems arise.
a) H2 is a dangerous bitch. Not only because it will ignite the moment it comes in contact with air, but also because such a leak is mostly undetectable because not only is H2 colorless and odorless, it's flame is also nearly invisible to human eye.

b) Since, H2 is very light, it will have to be compressed (a lot) to get any meaning full range out of the vehicle as well as to reduce the pumping/transporting costs. This means highly reinforced (and thus heavy) storage tanks as well as transport pipelines to take the very high hydrogen pressures. To bring things into perspective lets compare it with methane (CNG). Methane has a density of .717 kg/m3 at 0 deg C and a heating value of 54 MJ/kg which gives us 38.72 MJ/m3. H2 has a density of .0898 kg/m3 and heating value of 141MJ/kg which gives us 12.66 MJ/m3. Thus we need about three times the volume of H2 to get same energy output. If one was to use the tank of same volume then it would be much more heavier. Things looks even worse when you compare it with liquid fuels. So, saying that the tank will have twice the range is not correct as you might not even have the space to store enough H2 for same range.

Now, one could argue that there could be bigger/heavier tanks and robust systems. All that is fine if you want to produce electricity in a stationary unit, but in a Battle Tank. In a MBT your H2 tanks will have to be much more thicker to prevent any piercings as this will lead to catastrophic failures. For instance, in WW2 US shermans were much more susceptible to catching fire than German tanks as Americans used Petrol while the Germans used diesel.

Now coming to the making H2 in-situ part. This looks promising as one can use stuff like methanol which is fairly stable (though it burns with a clear flame too!!). But the problem is the kW/m3 rating as well as the cost of such devices. Now a quick google search about the current technology gives a grim picture. Ex. http://www.thehydrogencompany.com/subsiteproducts_11-310.html will sell you a 1kW device for 50,000 USD. Remember you need 10 of these to get close to the 1500 hp (1100 kW) rating desired. This high cost is mainly due to presence of rare metals (like platinum) in these devices.

http://www.ballard.com/files/pdf/Spec_Sheets/PEM_FC_Product_Portfolio.pdf

This is another company that sells automotive specific fuell cells also. These are very lightweight too. But their 150 kW device has a dimensions of 14.16 x 8.71 x 4.96 dm. This means a volume of 630 lts. Remember that you need atleast 7 such devices to get the desired output. Good luck getting that kind of a system in a battle tank.

So, the present systems are not that practical for our battle tank purposes. But what about the future.

Siemens is aiming to reduce the cost of their fuel cells to 400 usd/kW. That makes about 2 crores for 1100 kW which sounds reasonable. But their current system that generates 125 kW weighs about 25 Tons !!!! http://www.energy.siemens.com/hq/en/power-generation/fuel-cells/sofc-commercialization.htm#content=SFC-200%20Performance

Plus the same website also gives a comparison between various types of energy devices.

http://www.energy.siemens.com/hq/en/power-generation/fuel-cells/benefits-features.htm#content=Comparison%20of%20Fuel%20Cells%20and%20Other%20Distributed%20Generation%20Options

So, to conclude H2 hardly looks like a fuel that can power a battle tank, until and unless a cold fusion type of technique is employed which can give out a much larger energy output per kg of H2 than is possible by combustion. But we might have to wait a considerable amount of time for that to happen.

All this is generally true for any H2 system, prohibitively expensive and highly dangerous. And that is why even after decades of research even energy based on H2's chemical merits is not practical let alone from it's atomic merits. So, I have my doubts when people say that H2 is the fuel of future as even after an eternity of R&D there is not a single unit that can be mass produced and affordable.

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Re: Design your own tank

Postby SaiK » 15 Dec 2010 01:48

I doubt even CNG considering the logistic risks of diesel v/s CNG. But, if we find operational suitability, then we could consider least risky fuels.

OTOH, if oil dries out, then everyone is on the same page.

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Re: Design your own tank

Postby manish.rastogi » 15 Dec 2010 02:04

okay so maybe not hydrogen but still there are lot of other sources to power the tanks electrically....just finished reading about this stuff on wiki....will post links tomorrow but still if anyone is interested search electric cars,lithium ion batteries and you will find other related stuff there too....

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Re: Design your own tank

Postby sohamn » 15 Dec 2010 02:19

No pure electric tank or Fuel Cell Tank is going to work in next 50 years. This is my iron clad guarantee.

I work with a company that develops electric and hybrid cars. They are years ahead in terms of technology but still to charge the batteries fully it takes around 8 hrs. The batteries are also susceptible to heat and moisture. Moreover even the best can't provide power for more than 200 kms and I am talking about cars and buses.

As far as fuel cell is concerned the practical tried and tested fuel cells in the world works optimally below 40 deg, above that it starts degrading rapidly. Thats the reason fuel cell vehicle are not popular and prohibitively expensive. The fuel cell station opposite to my house doesn't see customers for days.
Moreover there are two other issues with fuel cell
- production of hydrogen is very expensive and it can't be specially produced only for tanks.
- Hydrogen is very volatile and explosive. It is not a fuel of choice in battlefields.

Let us rather focus on more practical tanks/ICVs which will serve the purpose.

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Re: Design your own tank

Postby manish.rastogi » 15 Dec 2010 02:47

^^^my friend you do might work in such company but please check electric cars article on wiki all the disadvantages you talked about electric vehicles are already covered up.....please go and check it!!

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Re: Design your own tank

Postby Gurneesh » 15 Dec 2010 03:09

The latest electric car in the market is Chevy Volt and that can run for a whole 40 miles per charge :rotfl: after which it needs to start up it's gasoline engine. Plus it takes about 10 hours to charge. Now, we are talking about the new benchmark in electric vehicles here.

Volt's battery weighs 170 kg (220 cell pack) and puts out 16 kW of energy in one hour . Please remember that one needs around a MW of electricity for a tank. This means we need around 69 such battery packs. That means ~ 11 Tons of battery weight to drive around for an hour. As efficient as batteries may be their power density is still not very good. Plus it would require a dedicated power plant (i am talking about those big ones and not some puny building generators) to charge a regiment of such tanks (which in itself would take an eternity to charge). Not to mention that 11 Tons of battery will cost much more than the tank itself and these things are also susceptible to exploding if temperature rises or their is some impurity.

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Re: Design your own tank

Postby bapatnikhil » 15 Dec 2010 03:31

So back to the basics are we? I dont care how fuel cells work. Unless it uses djinn powers, it needs refuelling and so bam, logistics.

I do care how things work and you should too. Without caring how something works and then commenting on it is just childish. People were "destroying" poor guy who asked if we can use fuel cells, so I decided to throw in some facts and divert the artillery to me :)
-basically means not yet mass production ready

Of course its not mass produced. Its a new technology.
- a complete new logistical chain required

Partially true. If you remember, I listed it as a con of fuel cells. Depends upon the type of hydrogen chain we consider. Not a problem is hydrocarbon based fuel cells are used. Fuel cells can be made to use most hydrocarbon based fuels and Hydrogen too.
- cost is a bummer

Costs get reduced with start in mass production.
no mass production, therefore no leverage over existing logistic chain

That was one of my points. I agree with you there.
-Note: Fossil fuels is too broad a term. If one car uses petrol, other car diesel and somebody says both are fossil fuels :wink:

As I said before, fuel cells can take normal fuels (diesel for eg.) but those are still in labs. :(
- will only work if you disband the entire army one day and create a new one

People did it when they shifted from horses to tanks...
- and all this for a mere 50% increase in efficiency

Two times more efficiency means 25% to 30% for diesel to 50% t0 60% for fuel cells is 200% increase in efficiency not 50%. Get your math straight.
so basically instead of leveraging civilian infrastructure, army will have to build its own infrastructure. :rotfl:

No. Standard infrastructure will be used till last node. In case of civilians it would be hydrogen station, in case of IA, it would be main base, if at all it is necessary, I do not know where IA stores and transports its fuels you can enlighten me here I do not think that IA has Petrol Pumps in those areas now. Those storages was I actually referring to.

and what of the increase safety features required for hydrogen handling?

It will be transfered as liquid fossil fuel and converted as and when required. As per safety of vehicle in question, it goes for all liquid fuels as well. Hydrogen can be stored in gaseous and adsorbed state. When in gaseous state, it is stored at about 700 bar, which is not very good when people are throwing bullets at you. But adsorbed state is the most safe as it stores it at very low pressures and it does not give out hydrogen even if it is exposed to air. But still again adsorption technology is nascent.

From your own post, I can see that you have not claimed cost, logistical, maintainence, non-complexity benefits :lol: Now again why should the IA move to fuel cells?

Al-gore and their minions marketing successes astonish me

I never said IA should adopt fuel cells. But if you have not noticed, we are all discussing a hypothetical tank using various technologies that BR members have heard about (like cold fusion) which will never be built, at least in my lifetime. From the posts I read, I got an impression that people do not know $hit about fuel cells. They were talking about having generators powered by IC engines to charge fuel cells which takes so much time and stuff like that. So I just wanted to point out some facts. My whole point was that unless we have a complete system of transportation converted to Hydrogen, it is not practical to run tanks on it.The Al gore comment is just insulting. No wonder so few new people join forums like this. Good thing I have a very thick skin and do not mind insults aimed at me :D

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Re: Design your own tank

Postby shiv » 15 Dec 2010 06:26

bapatnikhil wrote:As for hydrogen supply; there are several ways to solve this problem.
1)Have large Hydrogen Plants in a few locations and transport pure hydrogen via pipelines and tankers to local Hydrogen Pumps. The advantage is that very pure hydrogen, which is critical for fuel cells can be used.
2) have hydrogen generation plants at intermediate state for example instead of having only one huge plant supplying fuel to say Mumbai, Pune and Nasik, we can have three smaller plants each one for one city and then the fuel is transported to Hydrogen Pumps. Here also we maintain the purity of hydrogen, simplify transportation but cost of setting up 3 smaller plants is more than one huge plant.
3) Convert it at Hydrogen Pumps. The technology exists for this small scale conversion at each individual nodes but there purity of hydrogen is the issue. The main advantage of the third is that existing infrastructure for transportation and distribution of fossil fuels is used and hydrogen is generated as and when required.

In my opinion, the third is best suited for civilian while for our purpose second option looks best. The intermediate stations would be closer to areas operations but sufficiently inland to protect from enemy. Fossil fuels will be delivered to these stations conventionally and Hydrogen generated would be supplied to troops in that area using existing logistics chain, albeit using different equipment.


Excellent information. Let's see if we can get some practically implementable information of of this information

Aksai Chin is 5000 meters in altitude and there are no easy routes to get there from the Indian side. What i am interested in knowing is:

1) What would be the weight and volume of fuel cell per ton of vehicle to get a minimum range of 300 km on a 20 ton vehicle
2) What are the requirements for refuelling 10 such vehicles an hour - does it have to be a refuelling station or can there be a refuelling truck that follows the tanks/armored vehicles to the frontline?
3) What sort of infrastructure is needed for a refuelling station, mobile or static in terms of how the hydrogen is shipped in and transferred to a hypothetical refueling vehicle that follows tanks to the rear areas of a a battle zone that has moved from India to an area say 25km inside enemy territory.
4) How would a hydrogen fuel cell react to a hit from a 30 mm cannon shell? How does it react if it is exploded with a landmine?

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Re: Design your own tank

Postby shiv » 15 Dec 2010 06:45

bapatnikhil wrote:My whole point was that unless we have a complete system of transportation converted to Hydrogen, it is not practical to run tanks on it.


This is how I see it. This is a forum where people are allowed to have ideas. But a person who has an idea will have to come up with answers to quetions about how and why the idea is better than existing technology.

I think one thing that is missed in some discussions is that we all know very well that is is possible for humans to eat nails and razor blades with food and survive. So why don't more people do that? The point I am making is that there is a huge gap between what is theoretically possible and what is desirable and implementable.

If you are talking about a "pilot project" to introduce Hydrogen fuel cell buses in Bangalore, Kerala - then experimentation, trial and error are fine. But if you are talking about a force of 500 or 1000 tanks and armored vehicles being used by our fathers and brothers to fight an invading army Chinese army that does not give a flying fuk about fuel cells and uses dirty diesel in large quantities to overrun 5000 sq km of India territory - one has to think whether dreams about tomorrow's technology can win today's war? We can't say "Oh we have the infrastrcuture only to fuel up 20 vehicles. But he Chinese attacked us with 500, so we lost"

Research and war are two different things. Ideally a warfighting machine has to work perfectly and do what is demanded of it. If you build it out of technology that you don't have or are yet to develop - you have to be able to say why the technology will work on the battlefield, and answer questions about it. I think the same arguments/hurdles have come up in the LCA thread, the FGFA thread and the deign your fighter thread.

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Re: Design your own tank

Postby Singha » 15 Dec 2010 09:34

I am working on a 52t MBT which I will call the "Marauder". progress a bit slow due to being off alcohol these days...but by friday will have drawing...

basic concepts:
- merkava style front mounted engine (one side)
- 3 man crew in hull (driver beside engine and commander & gunner behind him side by side)
- 1000hp only diesel engine and compact form factor - i.e. not super high T:W but modest like challenger2
- cool air bleed and exhaust cooling and dissipating below the tank to reduce IR sig drastically
- electronic system to detect and jam mines and cellphone/radio signals (not sure how, but POTUS/MMS cavalcade does it)
- active cooling of hot areas to reduce IR sig (esp the main cannon barrel & HMG)
- intelligent 'skin' to take various patterns - in ladakh it will become bare brown and sand, in punjab it can match the scenery - eletrically activated by commander using a stored library and 360 cameras which can quickly pickup and produce the best camo for the terrain and time - at night it can become grey, while being sand colour in day in same place!
- additional overhang armour outside the tracks in the area of crew compartment and addl top attack protection over crew area
- the turret will be much smaller being unmanned
- all 120mm ammo will be in a normal sized bustle NOT inside the hull , so turret will be narrow in front but wide in back - like a wedge shape looking from top
- turret ring itself will be smaller in size as its unmanned. the addl space on the side freed up by this will be used for two smaller fuel tanks to extend range by couple 100km - useful for extended IBG ops and matching the endurance of trucks and ICVs.
- main fuel tank behind the turret (below the bustle)
- extra anti-ATGM rod armour cage around the two side and main(rear) fuel tank, with blow off panels to side and bottom
- the space behind the main fuel tank used to carry repair kit, beddings, food, water, medical kit, small arms, extra ammo for the HMG/main gun , smoke discharge system and a small remotely controlled ROVER armed with a camera and ground penetrating radar to scout really hostile places and locate threats like mines and hidden enemy positions
- waste heat recovery and electrical generation system to power some electricals
- solar panels atop rear area to soak up spare sunlight
- full air conditioning, heating and plush seating (power adjustments and lumbar support) with cold compartment to store food, medicines and drinks
- hydro pneumatic suspension
- air quality monitoring and purification system, with emergency oxygen cylinder
- usual NBC overpressure
- usual water fording

unmanned turret & autoloader:
------------------------------------
bustle to hold 45 rounds of mixed type (usual types + anti helicopter aam proximity fuse style round)
120mm L55 cannon - 1900m/s @ 2km using smokeless/low smoke propellent (to be replaced with 75mm scramjet shell cannon when available, 90 rds loadout)
dual thermals+tv (for gunner and commander) stacked in a slope in line with main cannon, with indep 360 traverse
driver 360 periscope & FLIR system and micro cameras (merkava style)
satcom/bms antenna dish clipped behind the bustle in recessed housing
remote weapons station featuring one 12.5mm HMG & 20mm cannon fed from within turret by electrical belt feed.
the 20mm cannon can be put in radar guided mode tasked by a small radar housed atop the bustle to deal with aerial threats like helicopters, large bombs or ATGMs or operate manually against ground targets by gunner/commander.
3000 rds of HMG ammo & 750 rds of cannon ammo carried internally in drums below the bustle which may be reloaded by rotating the turret sideways to an angle.
laser & missile warning system

No ERA, just composite armour , with dual layers around crew compartment as mentioned above

"AMOLED" touchscreen activated auto tracking and targetting system - gunner needs to touch the desired targets image and gun will automatically lay and maintain aim, gunner can proceed to mark next target and it will be queued. queue will be shown on screen and thermal vision AI system will automatically delete items seen to be hit by other tanks.
full GLONASS/GPS support and digital terrain maps to support group tactics, extended waypoint navigation in whiteout weather and ability to receive updates via satcom...

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Re: Design your own tank

Postby ArmenT » 15 Dec 2010 10:16

For all you gas turbine engine boosters, you're only looking at the advantages of the gas turbine and not considering the disadvantages (i.e.) logistics, fuel efficiency and cost. Imagine you're the Indian General and you're told that the price of the gas turbine engine is 10x the diesel engine, even with mass-production savings. Moreover, you're told that if you purchase this tank, you need to also purchase about 3x the number of fuel trucks to transport the fuel. Thirdly, you need to retrain existing personnel to maintain this engine and the cost of the replacement parts are more than that of a diesel engine. Lastly, whatever space you gain by using a gas turbine is used by a larger fuel tank, to match the range of a diesel engine. Now, would you purchase such a tank?

Also note that in Op. Desert Storm, speed of advance of the tanks was limited by the speed of their fuel delivery supply chain.

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Re: Design your own tank

Postby SaiK » 15 Dec 2010 11:14

ArmenT, your handle sounds like a nice name for a FMBT. What are your suggestion for the NG fuel? How do you intend to solve the dessert storm problem?

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Re: Design your own tank

Postby Tanaji » 15 Dec 2010 17:01

IMHO the advances in missile technology are rapidly outpacing the advances in armour technology. As a result, it will be increasingly difficult to develop tanks that will provide good protection AND have mobility and required fire power.

An armoured assault in an environment rich with Nag , Javelin type missiles is sure to suffer good casualties.

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Re: Design your own tank

Postby Pratyush » 15 Dec 2010 17:14

Tanaji,

This is a temprory phase. Armur is bound to catch up with the weapon and stailmate will be restored. That too in the near future it self.

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Re: Design your own tank

Postby manish.rastogi » 15 Dec 2010 18:24

Okay
I found that charging time range weight and logistics is creating problems......
i am posting links
http://en.wikipedia.org/wiki/Fuel_cells
http://en.wikipedia.org/wiki/Battery_el ... propulsion
http://en.wikipedia.org/wiki/Hydrogen_vehicle
http://en.wikipedia.org/wiki/Electric_vehicle_battery
http://en.wikipedia.org/wiki/Li-Ion
http://en.wikipedia.org/wiki/Genset_trailer
http://en.wikipedia.org/wiki/Electric_car

also i am quoting this from wikipedia
(i)Energy efficiency
Electric vehicle 'tank-to-wheels' efficiency is about a factor of 3 higher than internal combustion engine vehicles.[29] It does not consume energy when it is not moving, unlike internal combustion engines where they continue running even during idling. However, looking at the well-to-wheel efficiency of electric vehicles, their emissions are comparable to an efficient gasoline or diesel in most countries because electricity generation relies on fossil fuels.

(ii)A Li-poly powered Audi A2 covered the record distance of 600 km without recharging on October 26, 2010

(iii)Next-Alternative Carbon Nano Tube battery pack will deliver 380 miles (610 km) range and can be recharged in less than 10 minutes. The nowadays battery short life (three to four years, perhaps 200 full charge/discharge cycles) is extended by at minimum of 4 times with this technology.


I have always said that the tech i am saying needs further development and i see it in the time frame of 2017-2018!!You guys asked quite a no of questions(i absolutely have no problem with that).....but now i am tired of giving the same answers so this is my last post for this topic......i did some reading from these links on the topic and i am quite confident that what i said was totally achievable and realistic....(don't ask for details).....please go ahead and have a read of these links.....will definately clear your doubts!!!


Now....one more thing yesterday i posted a concept of tank.....i would love to hear your views about it!!!
Thanks.... :)


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