Little things like these go a long way in enhancing deployable Artillery firepower at the LoC :
IIT Madras developing Ramjet-powered artillery shell for Indian Army to hit targets more than 60 kms away
Lt Gen PR Shankar (retd), whose team had exhibited the theoretical possibilities of the project at the recently concluded Defence Expo in Uttar Pradesh, said that his team is working on an artillery shell that is based on the next-gen Ramjet technology.
Written By: Sidharth MP
Edited By: Ritesh K Srivastava
Feb 21, 2020, 18:09 PM IST
CHENNAI: The department of Aerospace Engineering at IIT Madras is working on developing a next-generation artillery shell that can be used by the Indian Army to hit far away targets with greater precision. Lt Gen PR Shankar, a (retd) Professor of Practice at IIT Madras, whose team had exhibited the theoretical possibilities of the project at the recently concluded Defense Expo in Uttar Pradesh, said that his team is working on an artillery shell that is based on the Ramjet technology.
“This will enable it to travel upto a range of 60 kms and above. Most shells that are in use travel around 30 kms or so. Extending the range of a shell would be highly useful in non-contact warfare scenario, like the situations on the Western border. Some of the current shells can travel upto 24 kms. We could extend the range unto 30 kms by traditional methods, but doubling it to 60 kms is going to be a game changer. Changing the gun would mean a tedious process, but instead we could change the ammunition and improve the performance,’’ he added.
When asked how compatible this new artillery shell would be with current artillery guns used by the Indian Army, Prof Shankar said, “Although we are developing a new kind of shell, we would not be building it from scratch. We are planning to redesign the existing shells using ramjet propulsion technology. The new shells are compatible with all the existing Artillery guns such as Bofors, Dhanush, Vajra and ATAGS. It is a fact that each gun has its own characteristics, but the shell we are developing is of a 155mm calibre. Hence, it would be usable on all Indian or foreign platforms that utilize the 155mm shell.’’
Further explaining how his method is different from the standard range-extension methods for Artillery shells, Prof Shankar said, “Traditionally, we would utilize a method called ‘base bleed’ where a chemical at the base of the shell burns, emits gas to fill the vacuum behind the shell to reduce the base drag force. Base bleed enables an increase of range by 10 to 20 percent. We are aiming to double the range by using ramjet propulsion technology through indigenously developed fuel and an air intake at the front, that helps the shell travel faster and thus enabling it to reach double the range.’’
When asked about the challenges pertaining to maintaining accuracy while aiming to extend a shell’s range, the retired Director General of Artillery said, “When a shell travels for around 30kms, the normal methods of correction are applicable. However when a shell travels 60kms, it would be affected by wind and weather conditions far more. So we would incorporate some kind of system to keep it on intended track. It is called a Precision Guided Kit. We will be developing the precision guided kits specially for such extended ranges.’’
Prof PR Shankar, who has been a Professor of Practice at IIT Madras’ Aerospace Engineering department and is actively involved in applied research, expressed hope that the Indian ordnance factories and facilities will be able to mass manufacture such shells for the Army’s requirements .
“Most of the shells that we need are made here. When we do resort to import it is only restricted to smart ammunitions and precision guided munitions (PGMs). Our ramjet based shell is like any other shell and we would be ensuring that OFB (Ordnance factory board) can manufacture it. Ability to manufacture it is there, but we are working on the design and the technology. That's where IIT Madras comes in, along with IIT Kanpur, Armament Research and development Establishment(ARDE) Pune and Research Centre Imarat (RCI) Hyderabad,’’ he said..
Replying to the question would there be a significant reduction in unit cost due to the indigenous manufacture, Prof PR Shankar added, “Primarily this technology is a first for artillery shells. Being a new product and new technology, they tend to be very costly. But it is certainly less expensive when compared to missiles and other weapons that have a range of over 60kms. There is also a scope for exporting this type of shell to friendly foreign countries.’’
Lt Gen P R Shankar is a retired Director General of Artillery. He has played a vital role in the modernization of Artillery through indigenization. He has deep knowledge, understanding and experience in successful defense planning and acquisition, spanning over a decade. Major 155mm Gun projects like the Dhanush, M777 ULH and K9 Vajra, Rocket and Missile projects related to Pinaka, Brahmos and Grad BM21, surveillance projects like Swati WLR and few ammunition projects came to fructification due to his relentless efforts. He has been a Professor of Practice at IIT Madras’ Aerospace Engineering department and is actively involved in applied research.
IIT Madras developing Ramjet-powered artillery shell for Indian Army to hit targets more than 60 kms away
IIT Madras put out a paper on their ramjet powered artillery round. The paper is titled : " Solid Fuel-rich Propellant Development for use in a Ramjet to Propel an Artillery Shell "
The link to the paper is here : ##article.pageTitle##
Let me see if I can unpack some details here. The general set up of the shell is as given below :
As the design shows the addition of an active power source(the ramjet engine) will drastically reduce the internal volume left for the explosive warhead. Thus the shell will travel farther but will produce less bang per round. To prevent the warhead from being so weak that it will be no good for taking out heavily fortified targets and also to make sure the round travels a sizable distance more to ensure the viability of putting a ramjet in a shell, special attention is to be placed on propellant selection. The propellant must have the following qualities :
- It must be shock resistant to prevent accidental detonation when the shell is fired from a artillery gun.
- It must be a fast burning fuel to ensure high speed of travel. This is crucial as the shell has no wings/fins, so all the lift generated will be body lift.
- It must produce high energy. Allowing us to get more energy output per unit mass of fuel. This is needed as there is a size and mass restriction for shells.
- It must also have a low oxidiser requirement. The propellant is meant to be fuel rich as in it will have a greater proportion of fuel than oxidisers. The fuel must be capable of under going complete combustion and leave no solid residue behind.
- It must be an economical fuel. Remember artillery shells are meant to be mass produced. If the fuel is uber expensive then the entire point of artillery is put to question.
The set up to test fuel burn rates :
Given the demand placed on the propellant the researchers have made the correct decision of basing the new propellant on proven components. The propellant is based on :
Aluminum(Al) : Fuel
Iron Oxide(IO) : Desensitized reactant.
Hydroxyl Terminated Poly Butadiene(HTPB) : Binder
Poly Tetra Fluoro Ethylene (PTFE) : Activator
Ammonium Perchlorate(AP) : A very powerful oxidiser
Let's go over them one by one :
1) Aluminium(Al) and Iron Oxide(IO) :
More specifically mechanically activated Aluminum. The Aluminum used here is not a bar/lump of metal but rather very fine powder produced by high energy ball milling of Aluminum pellets. This powdered Aluminum is called mechanically activated Aluminum. Why is making a powder important ? The reactivity of a metal is often subject to available surface area, a powder has more surface area than a bulk metal. Thus powdered Aluminum is more reactive than bulk. Aluminum like some other metals(like Magnesium) is often used in propellants to increase the energy output of a composite solid propellant. This is done by using an intensely exothermic reaction known as a "Thermite reaction".
From the internet : "A thermite reaction (a type of aluminothermic reaction) is one in which aluminum metal is oxidized by an oxide of another metal, most commonly iron oxide. Although the reactants are stable at room temperature, when they are exposed to sufficient heat to ignite, they burn with an extremely intense exothermic reaction. Thermite contains its own supply of oxygen, and does not require any external source (such as air). Consequently, it cannot be smothered and may ignite in any environment (it will burn perfectly well underwater, for example), given sufficient initial heat. "
The reaction is : Fe2O3 + 2 Al –---> Al2O3 + 2 Fe + Energy
The energy produced is around ~2000 Kilo joules/gm of Al. But the problem is that the reactants need to be heated to over a 1000 deg C for the
reaction to even start. So kick starting the reaction is not easy and will require some other energy source. That's where the other components come in.
2) Hydroxyl Terminated Poly Butadiene(HTPB) :
This is the polymeric binder holding the entire thing together. It is combustible and burns leaving no solid residue behind. It does produce enough energy when combusted that in certain propellants HTPB is both the binder and the fuel. HTPB is not a new thing by any measure. It is widely used by space organisations to make propellant for space fairing rockets. ISRO uses it on the PSLV, JAXA and NASA are also known to use it. Needless to say we already have world class production facilities to produce the HTPB, we are also currently the largest producer of HTPB in the world. So production and sourcing isn't a problem and is actually quite economical. The binder is used in the highest proportion in the propellant. Thus its price, availability etc plays directly into the overall cost per round.
3) Poly Tetra Fluoro Ethylene (PTFE) & Ammonium Perchlorate(AP) :
The PTFE is the activator or in other words the material with the lowest melting temperature(around 300 deg C). When a 155mm(52 cal) artillery is fired the muzzle velocity is over Mach 2. Air rushing in through the inlets will easily heat up beyond 300 deg C. This will cause the PTFE to melt and release Florine gas, increasing pressure and further heating up the combustor. Then the AP will take over, being an already unstable compound it will quickly breakdown and release a lot of oxygen. This will further increase the pressure inside the shell and also increase the temperature. The increased temperature will now ignite the HTPB, which will again increase temperature and increase pressure. Once the temp is above 1000 deg C and the pressure is high enough the thermite reaction begins.
It is a multi-step combustion process, of course the pressure and temperature are dynamic. The shell will keep ejecting hot gasses from the secondary nozzle the entire time, so the parameters inside will depend on rate of reactions. Of course the problem with a multi-step combustion is that the reaction rates, energy outputs etc are different for different reactions. For example when the thermite reaction initiates there will be a sudden surge of energy output, that might de-stabilise the flight of the round and throw it off target. It will be interesting to see how they go about dealing with these problems.
Anyway here are the compositions they experimented with. They have decided to go with the F5 composition :
I doubt the validity of this news, it says that rest 300 of SPH will be from DRDO which doesn't make any sense when army can simply buy K9 vajra from L&T. Secondly AFAIK, in FARP army envigased only 100 SPH and not 400.
"Under FARP, the army plans to acquire 1,580 towed howitzers, 100 tracked self propelled (SP) guns, 180 wheeled SP guns and 814 mounted guns systems. "
Field Artillery Modernization Program of the Indian Army. — Indian Defence News
After decades of setbacks and neglect, the artillery regiment of the Indian Army, is gearing up for major procurement processes, to address the short fallings in its war making capabilities. India after a decade...
defenceupdate.in
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I doubt the validity of this news, it says that rest 300 of SPH will be from DRDO which doesn't make any sense when army can simply buy K9 vajra from L&T. Secondly AFAIK, in FARP army envigased only 100 SPH and not 400.
"Under FARP, the army plans to acquire 1,580 towed howitzers, 100 tracked self propelled (SP) guns, 180 wheeled SP guns and 814 mounted guns systems. "
Field Artillery Modernization Program of the Indian Army. — Indian Defence News
After decades of setbacks and neglect, the artillery regiment of the Indian Army, is gearing up for major procurement processes, to address the short fallings in its war making capabilities. India after a decade...
That Twitter thread is all made up.
**** guy, masala maker.I doubt the validity of this news, it says that rest 300 of SPH will be from DRDO which doesn't make any sense when army can simply buy K9 vajra from L&T. Secondly AFAIK, in FARP army envigased only 100 SPH and not 400.
"Under FARP, the army plans to acquire 1,580 towed howitzers, 100 tracked self propelled (SP) guns, 180 wheeled SP guns and 814 mounted guns systems. "
Field Artillery Modernization Program of the Indian Army. — Indian Defence News
After decades of setbacks and neglect, the artillery regiment of the Indian Army, is gearing up for major procurement processes, to address the short fallings in its war making capabilities. India after a decade...
When it comes to the military, they will pay for even the slightest advantage when it's good.
Anyway, I have no clue what the army will actually do with the ATHOS now. If ATAGS works as intended during the upcoming trials, the ATHOS can also end up being cancelled without creating a diplomatic incident. We have cancelled far too many tenders, and the Israelis are particularly pissed about the Spike deal. The Israelis realise they are slowly losing India as a market, and that's a big problem for them. But COVID can be a potential excuse.
The endless time spent on tenders actually works in favour of indigenous development. The army began the ATAGS program and the new ATHOS tender at the same time. They probably thought they will get the ATHOS (or whichever gun won the tender) long before the ATAGS becomes available. But this is India...
However, the artillery requirement is so massive that importing 400 guns won't be a problem. The IA will likely favour simultaneous inductions of three types of such guns. Plus the ATHOS is the cheapest of the three types. Our towed gun requirement alone is 3000-4000 in total.
ATAGS is having bit extra weight and it is bit far away from series production too, as a stop gap measurement we can give extra few hundred orders for k9 Vajara.L&T has done a meticulous job on keeping up with time frameWhen it comes to the military, they will pay for even the slightest advantage when it's good.
Anyway, I have no clue what the army will actually do with the ATHOS now. If ATAGS works as intended during the upcoming trials, the ATHOS can also end up being cancelled without creating a diplomatic incident. We have cancelled far too many tenders, and the Israelis are particularly pissed about the Spike deal. The Israelis realise they are slowly losing India as a market, and that's a big problem for them. But COVID can be a potential excuse.
The endless time spent on tenders actually works in favour of indigenous development. The army began the ATAGS program and the new ATHOS tender at the same time. They probably thought they will get the ATHOS (or whichever gun won the tender) long before the ATAGS becomes available. But this is India...
However, the artillery requirement is so massive that importing 400 guns won't be a problem. The IA will likely favour simultaneous inductions of three types of such guns. Plus the ATHOS is the cheapest of the three types. Our towed gun requirement alone is 3000-4000 in total.
Now that a 2 front Situation is getting closer by the day , Every additional Gun ,Every additional Barrel and Every additional Shell is important
The user trials coming up next will be for a version that's 6T lighter.
More than weight, the cost will matter. Becoz anyways we will have M777 for use at altitude and we are also looking at mounted 155/39 calibre all steel guns too maybe for high altitude warfare.
The 155/52/45 towed ones will be required in numbers of around 2000. Cost will come into play. It should be competitive.
Yeah, cost will definitely be a problem.
They made it too heavy, and the lighter titanium version is much more expensive than ATHOS.
We should have answers by the year end.
The article says that ATHOS failed structural integrity test(kind of a big deal right?) and Saurav jha has also said that ATAGS has cleared all the mobility trials and he doesn't know why army is complaining about weight. Using Titanium will reduce weight but increase the cost, which means the only option is to redesign it to reduce weight which means 2 to 3 years minimum delay. I think we will have another Arjun saga.
Only saving grace is that Sitharaman has cleared 140 LSP...
Do you know what is the reason behind not ordering K9- Vajra. AFAIK it is one of the best tracked howitzers in the world. A 400+ of these in western IB can flatten any armored, infantry thrust from pakistan
I remember L& T reporting orders will be made on time.
Without orders shop will have to be closed in 6 months ..