Skywatcher
Captain
You can build a TEL for a 110 foot gun with modern tech.
I just can't make any guarantees that you could build it to military specs, or that you can take it on the highways or cross country.
Chinese Supergun?
- Thread starter AssassinsMace
- Start date
You can build a TEL for a 110 foot gun with modern tech.
I just can't make any guarantees that you could build it to military specs, or that you can take it on the highways or cross country.
No, it is trivial to pin point any gun that fired a ballistic shell by calculating its trajectory backwards, Even if the shell is seen only during terminal stage of its descent.
Any gun betrays its location by firing just once, and if a super heavy gun isn't mobile, and can't shoot and scoot, it will be targeted literally the minute it fired.
Once a missile warhead separated from the booster, the missile warhead is just as difficult to intercept as a shell. The terminal speed and trajectory of a artillery shell and ballistic missile warhead fired over comparable ranges would be similar. If anything, the missile tend to have greater throw weight, and have more potential to defeat interception efforts by deploying penetration aids.
A missile in the boost stage would be easier to shoot down than a shell just fired out of a gun. But, if the enemy can reach over the launch site to shoot down a missile in boost phase, it probably has the technical wherewithal to attack the gun that fired the shell,
Anyway you look at it, a gun has few advantages and many disadvantages compared to missile for ultra long range warhead delivery.
The gun have equal advantages to disadvantage compared to missile for long range warhead delivery. p.s. gun is mobile, for the 400-600 km range.
Pros:
munition is much cheaper
munition is harder to intercept due to lack of a boost stage
Barrage fire is capable, you will get more rounds in the air compared to a missile launcher before the launcher is neutralized
munition is more stable in flight - no need to separate booster and another million things that can go wrong in a rocket launch,
Guns are not bound by ballistic missile treaties
Con:
Gun is much harder to construct than a missile launcher
Launcher setup time is longer.
For the massive super guns - including rail guns, they have their merit to launch single decapitating strikes with WMD or cheap launch of satellites into orbit prewar.
The comparative virtues of a gun vs a missile system for warhead delivery are simplified if we examine them from the perspective of thermodynamic (as opposed to say, electromagnetic) devices for launching a projectile (or payload) over a given range.
Viewed as a gas engine, with the role of the piston assumed by the projectile, guns are relatively efficient. Some 30% of the thermal energy of the propellant can be used to propel the projectile.
Solid rocket motors are nowhere near as efficient in converting their propellant energy to the missile's kinetic energy.
Furthermore they suffer the comparative disadvantage of having to accelerate the entire missile rather than just the warhead.
The booster must move the whole missile, then next stages move themselves as well as the warhead, and so on and so forth, until the staging and/or propellant is used up.
This is why missiles are so profligate with propellant.
And why guns need very little by comparison (for the same velocity and range).
There are however major limitations to guns as propulsive devices.
1) there is a maximum velocity that can be imparted to a projectile by the charge alone.
2) the acceleration is violent and delivered as a sudden blow, necessitating robust construction both of the gun and the projectile.
3) the practical size of the projectile is small compared to a missile system.
4) the gun must have additional systems for recoil and gun-laying, making a mobile (or static) gun assembly comparatively more complex than a those for a missile - who's control system is built-in.
Dr Gerald Bull's contribution to gun design was to take the then existing gun technology (much of it German) and maximize it.
Namely he:
1) lengthened the gun barrel to as much as was practicable, allowing a longer time for the projectile to be pushed by the propellant charge. This also led to
2) larger amounts of slower and lower-temperature burning, propellants, raising the pressure in the barrel so that the projectile experienced greater total propulsive force; which in a gun occurs at a much higher pressure than in a rocket motor.
- this is an advantage, as peak operating pressures in a rocket motor's casing is limited by it's own mass, which after all must light enough to be able to fly, something that is not required of a gun barrel.
- it must be noted however, that both gun and rocket suffer from the need to keep their propellant burning temperatures down (as much as possible) as these (in addition to the high pressure) are detrimental to the life of the gun barrel and the rocket motor casing and nozzle.
- of course the advantage of a rocket is that the after firing, re-use is not an issue.
3) lowered the friction inside the gun barrel by developing (or adapting a German idea) a different form of rifling.
4) developed better aerodynamic shapes for his projectiles, lowering drag and enhancing stability, allowing them to fly further and more accurately.
5) developed range-enhancing and dispersion-reducing base-bleed projectiles.
Modern artillery using Extended-Range, Full-bore, Base-bleed rounds with double to triple the range of ordinary artillery shells are a direct consequence of his work.
Further enhancement like guided munitions have made modern artillery very different from even what was fielded in the Vietnam War.
Perhaps one way of taking advantage of the gun's virtues without resorting to the massive weight would be to fire missiles from something like a recoilless rifle and then using a ramjet engine to provide the extended range.
That would combine the relative advantages of both gun and missile systems.
Viewed as a gas engine, with the role of the piston assumed by the projectile, guns are relatively efficient. Some 30% of the thermal energy of the propellant can be used to propel the projectile.
Solid rocket motors are nowhere near as efficient in converting their propellant energy to the missile's kinetic energy.
Furthermore they suffer the comparative disadvantage of having to accelerate the entire missile rather than just the warhead.
The booster must move the whole missile, then next stages move themselves as well as the warhead, and so on and so forth, until the staging and/or propellant is used up.
This is why missiles are so profligate with propellant.
And why guns need very little by comparison (for the same velocity and range).
There are however major limitations to guns as propulsive devices.
1) there is a maximum velocity that can be imparted to a projectile by the charge alone.
2) the acceleration is violent and delivered as a sudden blow, necessitating robust construction both of the gun and the projectile.
3) the practical size of the projectile is small compared to a missile system.
4) the gun must have additional systems for recoil and gun-laying, making a mobile (or static) gun assembly comparatively more complex than a those for a missile - who's control system is built-in.
Dr Gerald Bull's contribution to gun design was to take the then existing gun technology (much of it German) and maximize it.
Namely he:
1) lengthened the gun barrel to as much as was practicable, allowing a longer time for the projectile to be pushed by the propellant charge. This also led to
2) larger amounts of slower and lower-temperature burning, propellants, raising the pressure in the barrel so that the projectile experienced greater total propulsive force; which in a gun occurs at a much higher pressure than in a rocket motor.
- this is an advantage, as peak operating pressures in a rocket motor's casing is limited by it's own mass, which after all must light enough to be able to fly, something that is not required of a gun barrel.
- it must be noted however, that both gun and rocket suffer from the need to keep their propellant burning temperatures down (as much as possible) as these (in addition to the high pressure) are detrimental to the life of the gun barrel and the rocket motor casing and nozzle.
- of course the advantage of a rocket is that the after firing, re-use is not an issue.
3) lowered the friction inside the gun barrel by developing (or adapting a German idea) a different form of rifling.
4) developed better aerodynamic shapes for his projectiles, lowering drag and enhancing stability, allowing them to fly further and more accurately.
5) developed range-enhancing and dispersion-reducing base-bleed projectiles.
Modern artillery using Extended-Range, Full-bore, Base-bleed rounds with double to triple the range of ordinary artillery shells are a direct consequence of his work.
Further enhancement like guided munitions have made modern artillery very different from even what was fielded in the Vietnam War.
Perhaps one way of taking advantage of the gun's virtues without resorting to the massive weight would be to fire missiles from something like a recoilless rifle and then using a ramjet engine to provide the extended range.
That would combine the relative advantages of both gun and missile systems.
Kurt
Junior Member
A supergun makes little sense for extended range through the atmosphere.
Range is equal to speed and increased speed results in square increase of drag.
That's why railguns are useful as point defense systems and rocket engines and cruise missiles for long range artillery.
A supergun does have extended range if it shoots projectiles out of the atmosphere.
As soon as that size and energy barrier is broken, a projectile can travel a long distance without drag.
It's possible to flip like a stone above water in space above earth atmosphere over that distance.
Afterwards the projectile falls down from space and there's no system to defend against it.
It's similar to Project Thor, a kinetic bombardement from earth orbit with the supergun as a suitable launch vehicle.
The advantage over missiles is the much shorter time it takes from launch to strike.
The problem with that project was guidance precision, because it's impossible to have sensors on the kinetic energy projectile and it will be hard to put them on a projectile acclerated by that gun.
It might be possible that they are running tests with guns and sensors in order to put guided munitions into superguns. as soon as that is accomplished, China does have a major breakthrough that would affect global and space strike capability.
Happy researching.
Range is equal to speed and increased speed results in square increase of drag.
That's why railguns are useful as point defense systems and rocket engines and cruise missiles for long range artillery.
A supergun does have extended range if it shoots projectiles out of the atmosphere.
As soon as that size and energy barrier is broken, a projectile can travel a long distance without drag.
It's possible to flip like a stone above water in space above earth atmosphere over that distance.
Afterwards the projectile falls down from space and there's no system to defend against it.
It's similar to Project Thor, a kinetic bombardement from earth orbit with the supergun as a suitable launch vehicle.
The advantage over missiles is the much shorter time it takes from launch to strike.
The problem with that project was guidance precision, because it's impossible to have sensors on the kinetic energy projectile and it will be hard to put them on a projectile acclerated by that gun.
It might be possible that they are running tests with guns and sensors in order to put guided munitions into superguns. as soon as that is accomplished, China does have a major breakthrough that would affect global and space strike capability.
Happy researching.
Skywatcher
Captain
The only possible military application for this supergun that you can't do with anything else is bunker busting.
Shooting a several ton projectile at hypersonic speeds onto a DPRK/ROC bunker could be powerful as a GBU-57A/B (since the PLAAF doesn't have any bombers that can carry a 15 ton bomb, not even in the likely forseeable future).
Shooting a several ton projectile at hypersonic speeds onto a DPRK/ROC bunker could be powerful as a GBU-57A/B (since the PLAAF doesn't have any bombers that can carry a 15 ton bomb, not even in the likely forseeable future).
I can't believe that you guys are still talking about this.
It has been proven on the Chinese forums that this is nothing more than drainage pipes (or some other kind of pipes) and NOT a super gun.
Oh Janes, when are you going to learn????
It has been proven on the Chinese forums that this is nothing more than drainage pipes (or some other kind of pipes) and NOT a super gun.
Oh Janes, when are you going to learn????
On what grounds did they prove it?
Because why would there be velocity/penetration targets right in front of the "pipe"? And why would there be a large mound of dirt behind one end of the "pipe" that looks perfectly in place to absorb back shock?
It was SOC who found the photo and went to the conclusions, and he's one of the most respected IMINT guys around btw
Because why would there be velocity/penetration targets right in front of the "pipe"? And why would there be a large mound of dirt behind one end of the "pipe" that looks perfectly in place to absorb back shock?
It was SOC who found the photo and went to the conclusions, and he's one of the most respected IMINT guys around btw
Hi, good post
Here wiki link explained that rocket engine can get 70% energy efficency and if the rocket travel at the same speed as exhaust gas then all that energy is converted to kinetic energy:
What do you you think about that link?
Also I think gun can get much higher than that as diesel engine can get to 60% and pressure in gun chamber is much higher than piston engine.
I heard that burning temperatures is the worst factor contributes to barrel erosion. Could you explained about this a little?
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Hmmm. Interesting.
What the wiki-author means by 'propulsive efficiency' is the actual energy imparted to the burning fuel stream leaving the rocket nozzle vs the initial chemical energy stored in the rocket fuel.
What I mean by 'propulsive efficiency' is the energy imparted to the projectile (not a complete rocket assembly) as it is the projectile which is being fired at the target.
Also, there is also a mis-conception here, as guns impart energy to their projectiles by pressure from the burning gasses, with chamber pressures as high as 50,000+ psig.
So as an example for a 155 mm (6 inch) gun/howitzer the base has an area of A = pi * r^2 in this case:
A = 3.14 * 3^2
A = 28.27 square inches
So the propulsive force is gun chamber pressure of 50,000 lbs / in^2 * 28.27 in^2
F = 1,413,716.7 lbs! (wow!)
Rockets on the other hand rely on ejecting mass at high speed out the back nozzle to accelerate the projectile.
This is called THRUST and generates a propulsive IMPULSE, and is less efficient than accelerating a mass initially by pressure (up to certain ranges and velocities).
If I remember correctly, it is expressed as a change in momentum p, where p = m * v (mass x velocity).
So (change in momentum) dp/dt = m * dv/dt + v * dm/dt. (derivative of a product)
The first part of this is Newton's second law; F = m * a, where a = dv/dt. (acceleration)
The second part is the IMPULSE, = v * dm/dt where the change in momentum is produced by a stream of mass, (the rocket fuel) ejected a the rocket's exhaust velocity, v.
This is the basic rocket equation.
The problem is that the rest of the rocket casing/staging is superfluous or rather, added baggage and mass needed to contain the propellant to accelerate the projectile.
In a gun, what will matter to the target is the projectile, and although a great enormous rocket assembly flying at you might seem impressive, for short ranges, it is a rather difficult and wasteful way to get that projectile on target.
Just look a the small quantity of propellant a gun (say a 52 cal 155 mm howitzer) needs to fire its 50 kg High Explosive ERFB-BB round to a range of 50+ km vs the vast amount of rocket propellant needed to fire a similar missile warhead the same range and you will see the vast difference in efficiency between a gun and rocket over these relatively modest ranges.
Comparing a gun to an engine works up to a point, the fact is most large marine diesel engines have maximum efficiency when the stroke is around 3.5 times the bore, any more and friction losses outweigh gains.
In a 52, 60 or longer caliber gun barrel, the friction problem gets worse.
And to impart maximum energy to the projectile, the propellant must be low-temperature and slow-burning exerting a prolonged 'push' onto the projectile.
Still there is the matter of diminishing returns, as longer and longer gun barrels do not provide the same degree of energy to the projectile.
As to the barrel erosion, I would think that's rather obvious, as high temperatures melt and erode the metal inside the gun's chamber and barrel, wearing out the gun.