What is the ultimate frontier for Dhanush guns?
Yes, This Is A Ramjet Powered Artillery Shell And It Could Be A Game Changer
Norway’s Nammo has unveiled a potentially revolutionary concept at EUROSATORY 2018 for an air-breathing, ramjet-powered artillery shell that any standard 155mm howitzer can fire at targets around 100 km away.
The defense contractor revealed a full-size mockup of the design, which it is simply calling the 155mm Solid Fuel Ramjet at present. The firm expects to begin live-fire testing of the projectile in 2019 or 2020 and hopes to have the new ammunition in production and in operational service with a military by between 2023 and 2024.
PRESENT RANGE OF ARTILLERY:
“This could be a game-changer for artillery,” Thomas Danbolt, Vice President of Nammo’s Large Caliber Ammunitions division, said in a press release headlined “We are basically launching a missile from a cannon!”. “With the exception of a small number of precision-guided shells with 50-60 range, most artillery systems still fire across the same distances as they did when the M109 was introduced more than 50 years ago.”
Incidentally, Dhanush (155x45mm) currently has a range of 38-40 km.
Self-propelled towed M-777 (155x39mm) howitzers which India is importing, have maximum ranges of around 20 km using standard high-explosive shells. Using rocket-assisted ammunition, they can hit targets closer to 32 km away. Nammo is separately working on an improved, rocket-boosted shell for M-777, the XM1113, which will have a maximum range of approximately 40 km.
By extending the length of the howitzer’s barrel, the plans are to nearly double those ranges. That still won’t be anywhere close to the more than 100 km maximum range that Nammo says it will be able to get out of its ramjet-powered projectile.
HOW WILL RAMJET POWERED SHELL WORK?
According to the Norwegian company, the firing cycle would remain essentially the same for artillery crews, who would fire the projectile like any other shell. But normal shells essentially begin decelerating the moment they leave the cannon.
The ramjet round uses the force of launch to get it moving fast enough to start the ramjet motor. A solid fuel source will get the projectile up to a maximum speed of three times the speed of sound and keep it moving at that speed for approximately 50 seconds.
This type of motor also reduces drag on the shell itself, since it’s actively pulling the projectile through the air. The firm, which has long built rocket motors for other companies’ missiles, says it is looking into developing its own ramjet missile using the same technology, as well.
So far it can’t be said how much volume within the shell has to go toward the ramjet and fuel rather than explosive or other payloads, which could reduce the punch of the round. However, the solid propellant offers an efficient fuel source and will help keep as much space as possible free within the body.
Pop-out fins and an unspecified guidance system will steer the projectile to its designated target. A GPS-assisted inertial navigation system (INS) arrangement will almost certainly guide the shell, at least at first.
A laser- or millimeter wave radar-guidance package could add additional flexibility to the system in the future. These systems could allow the projectile to hit moving targets at long ranges and, in the case of a laser-guided round, with manned or unmanned aircraft or forward-deployed troops on the ground designating the target with a laser or otherwise sharing that information with the artillery unit
FUTURE IMPLICATIONS OF RAMJET POWERED SHELL:
Ramjet round wouldn’t just extend the maximum range of a single howitzer, but would greatly expand the flexibility of individual artillery units to engage different targets. For instance, a six-gun battery would be able to hit anything within an approximately 4000 square km circle around their firing position with the new XM1113. The ramjet rounds would exponentially increase that possible target area to more than 30,000 square km without the howitzers ever having to relocate.
What this means is that ground forces could operate far further while still having vital artillery support on call. Fewer artillery units could also cover a much wider front. Perhaps most importantly, it would allow the howitzers to sit much further removed from the front lines, better protecting them from immediate enemy counter-battery fire and air strikes.
It might even make it a viable option to fire the guns from the decks of amphibious ships and sea bases, turning those vessels into floating firebases. And in the same vein, such a ramjet round could be an ideal option for the Indian Navy to be fired from Vishakhapatnam class of destroyers. Practically, once developed this shell will have applications from any platform that is wide enough to house a Dhanush gun.
OTHER ALTERNATIVE FOR INCREASING RANGE OF ARTILLERY :
Ramjet-powered shell is not the only concept that companies are pitching to squeeze more range out of existing 155mm howitzers. There is an intent to separately explore the possibility of launching inert, hypervelocity projectiles derived from experimental railgun ammunition from standard cannons. These would reach the same speed as the ramjet round, but would still likely have a significantly shorter overall range.
WHAT CHALLENGES RAMJET POWERED SHELLS WILL POSE?
There inevitably arises a cost question when it comes to wear and tear on the gun barrels. The more rounds you fire at higher speeds through a howitzer, the faster the rifling and overall structural integrity of the system wears down. This reduces overall accuracy and can potentially lead to catastrophic failures.
Depending on how fast crews need to fire the ramjet shells to get them to the appropriate speed, and whether or not the round’s motor begins to work inside the barrel, the ammunition could exert a high strain on the howitzer’s barrel and shorten the time before units need to replace them. Improvements to the existing guns could help mitigate these issues and extend barrel life, but would again require additional time and resources.
Whatever happens, there’s no denying that the ramjet artillery shell, if it works, will be an impressive feat of engineering and could offer game-changing capabilities for Dhanush howitzers of Indian Army.
Hopefully, bosses at DRDO and Ordnance Factory Board are listening!