Application of railgun?

[visser300]

I have a debate in another forum about application of railgun of US Navy. One argues that its incredible speed and shooting range is perfect for naval warfare. On the other hand, I see no application for it. Firstly, the gun is too big and complicated. Secondly, it consumes an enormous power which will require a nuclear reactor to provide that energy. Thirdly, if the gun is in attacking role, it is not comparable to the current guided missle in modern naval ships because they are extremely accurate, has a very long range and consume a little energy.

If the gun is in defence role, it is not comparable to automatic cannon and gating guns which have greater firerate, cheaper and consume little energy.

What do you think?

[Påsan]

That with a good targeting system a railgun could shoot down any aircraft or missile long before it ever becomes a threat?

[visser300]

That with a good targeting system a railgun could shoot down any aircraft or missile long before it ever becomes a threat?

I think that guided missle is good enough?

[removeduser_4536284751384]

I think that guided missle is good enough?

Guided missiles are not nearly as accurate as you think. In the 1980s American military planners found that 40% of ballistic missiles would experience some sort of failure before hitting their targets. Other missiles are even less accurate than that, especially against moving targets that are actively trying to evade and using countermeasures.

This would be an ideal weapon for space. Small non-explosive relatively light ammo which is basically non-interceptable.

Wouldn't gravity be enough to just drag down steel darts?

[Phier]

Wouldn't gravity be enough to just drag down steel darts?

I was thinking A-ICBM and anti-satellite.

[Holger Danske]

Railguns are going to make their military debut soon. A railgun shell is much cheaper than a cruise/guided missile, and it doesn't require a warhead to kill heavily armored targets because of it's extremely high kinetic power, eliminating the need for dangerous explosives on board for this particular role.
Furthermore their high muzzle velocity could (with the right targetting systems) make them potent in a defensive role, but not as CIWS, more of a stop-gap between them and the Aegis missile defense system.

As for their size and power consumption... Both can be improved over time as technology allows for better power supply and miniturisation. One huge advantage is that the railgun doesn't have moving parts, beyond those for controlling the barrel, turn the turret, and load the shell. With time we may even be able to make GPS guided shells that can survive the violent launch from a MAG.

I most certainly see railguns being applied in an anti-tank role. Even as the primary armament of some MBTs.

[DisgruntledGoat]

I most certainly see railguns being applied in an anti-tank role. Even as the primary armament of some MBTs.

It is going to be a VERY VERY VERY VERY long time before main battle tanks are rolling into battle with railguns.


As to the benefits of a railgun that's easy. Because of the velocities involved a sold mass non-explosive projectile fired from a railgun at say mach 10 causes the same or more damage than a tomahawk missile. But for a FRACTION of the cost to produce said projectile. Factor in a possible insane rate of file and the possibilities of true "shock and awe" tactics become apparent. Its not about sinking ships or cutting threw tanks like butter. Weapons already can do that. Its all about cost per kill and doing it in spectacular fashion. And if there is one thing the military has always liked its doing deadly things in crazy cool ways.

[Mangalore]

One limitation of railguns would be the necessity of direct fire capability. That'd limit its range on the seas or with geography in the way. Missiles can shoot over the horizon, evade obstacles, use indirect routes and hunt down their targets. I don't see how GPS guided shells would still be cheap. Also while ammo is cheap the energy storage and power source may not be. If current prototypes take a day to load their condensator and a reactor capable to supply a town then other inhibitions might also be not cost but time to recharge a shot.

[visser300]

It is going to be a VERY VERY VERY VERY long time before main battle tanks are rolling into battle with railguns.


As to the benefits of a railgun that's easy. Because of the velocities involved a sold mass non-explosive projectile fired from a railgun at say mach 10 causes the same or more damage than a tomahawk missile. But for a FRACTION of the cost to produce said projectile. Factor in a possible insane rate of file and the possibilities of true "shock and awe" tactics become apparent. Its not about sinking ships or cutting threw tanks like butter. Weapons already can do that. Its all about cost per kill and doing it in spectacular fashion. And if there is one thing the military has always liked its doing deadly things in crazy cool ways.

You have to include these cost below:
- the amount of power to make it run
- How much does it cost to make this gun and maintanance it?
- the number of crews who will operate it.
- How much does it cost to make a power supply to provide enough power for this monster?

[visser300]

One limitation of railguns would be the necessity of direct fire capability. That'd limit its range on the seas or with geography in the way. Missiles can shoot over the horizon, evade obstacles, use indirect routes and hunt down their targets. I don't see how GPS guided shells would still be cheap. Also while ammo is cheap the energy storage and power source may not be. If current prototypes take a day to load their condensator and a reactor capable to supply a town then other inhibitions might also be not cost but time to recharge a shot.

Not to meantion that weather at sea is crazy. A guided missile will still work in bad weather ( storm, rain). This gun will probably not able to do that.

[visser300]

It is going to be a VERY VERY VERY VERY long time before main battle tanks are rolling into battle with railguns.


As to the benefits of a railgun that's easy. Because of the velocities involved a sold mass non-explosive projectile fired from a railgun at say mach 10 causes the same or more damage than a tomahawk missile. But for a FRACTION of the cost to produce said projectile. Factor in a possible insane rate of file and the possibilities of true "shock and awe" tactics become apparent. Its not about sinking ships or cutting threw tanks like butter. Weapons already can do that. Its all about cost per kill and doing it in spectacular fashion. And if there is one thing the military has always liked its doing deadly things in crazy cool ways.

IF you can make it to run at March 10. At March 7, it already consume a ernomous power that only nuclear reactor could provide. So if navy wants to put those guns on their ship. It must run much slower than that.

[DisgruntledGoat]

Alright mister triple poster. The energy point was already made I was elaborating on the reasons for pursuing this tech. Why aren't there any railguns in action now? Answer, the energy cost. But once that problem is solved then its off to the races. If we were to abandon all tech that was impractical now no R&D would ever be undertaken. The OP asked their purpose, and their purpose is to reduce the cost of doing war.

BTW, MACH 10 and MACH 7 no R in that. Mach numbers tell you an objects speed relative to the speed of sound under the temperature and pressure conditions of the fluid the object is travelling through. And no it doesn't need to be fired at slower speeds. The work that needs to be done is finding efficient ways to provide 64-88MJ of energy to the gun. But that's what R&D is for.

Edit: with regards to power supply issue. A railgun requiring 88MJ to function would require, go figure, an 88MW power plant. An 88MW power plant can be constructed from two very small steam powered generators and a single steam boiler. Nuclear reactors in ships and submarines range from 10MW to 300MW depending on size ( http://www.world-nuclear.org/info/inf34.html ). Its definitely not outside of realm possibility to put a railgun on a ship RIGHT NOW.

[Phier]

I'm not sure of the velocity loss over distance, but a rail gun would not need to be direct fire.

[Mangalore]

I'm not sure of the velocity loss over distance, but a rail gun would not need to be direct fire.

Since its sole energy is kinetic aka via the speed of the projectile the options for worthwhile trajectories wouldn't be as big as a missile's which you can essentially fire into every which direction and assuming it as the fuel it can turn and still hit the target.

I'm not sure you should try putting high explosives into a railgun slug to increase their lethality on ballistic trajectories with explosives.

[Phier]

There is another application of the rail gun that everyone here should know and no one is talking about....



This would be an ideal weapon for space. Small non-explosive relatively light ammo which is basically non-interceptable.

Since its sole energy is kinetic aka via the speed of the projectile the options for worthwhile trajectories wouldn't be as big as a missile's which you can essentially fire into every which direction and assuming it as the fuel it can turn and still hit the target.

I'm not sure you should try putting high explosives into a railgun slug to increase their lethality on ballistic trajectories with explosives.

The question would be at what ranges does the rail gun become ineffective and to that I have no idea.

[DisgruntledGoat]

There is another application of the rail gun that everyone here should know and no one is talking about....



This would be an ideal weapon for space. Small non-explosive relatively light ammo which is basically non-interceptable.



The question would be at what ranges does the rail gun become ineffective and to that I have no idea.

While ideal for space it is illegal for the US to place weapons in orbit. Well, I suppose the treaty actually says weapons of mass destruction in space. So a precision weapon fired from orbit may get around the outer space treaty.

[Sphere]

Edit: with regards to power supply issue. A railgun requiring 88MJ to function would require, go figure, an 88MW power plant. An 88MW power plant can be constructed from two very small steam powered generators and a single steam boiler. Nuclear reactors in ships and submarines range from 10MW to 300MW depending on size. Its definitely not outside of realm possibility to put a railgun on a ship RIGHT NOW.

Thats a bit of a distortion of the physics. The system is based on large banks of capacitors, not a directly applied current so there is no minimum power plant size.

The capacitance of any device (in otherwords its ability to store energy) is just Charge/Voltage.And as you can step voltage up or down as much as you like regarless of the the power source, the massive banks of capacitors that power these rail guns could be charged up to 88MJ of energy from any power source no matter how small.

The only problem is the time to recharge. Generally speaking, the charge on a capacitor vs. time (at a constant voltage) looks like this.




Which means the rate decays overtime, so even with a massive 88M joules/sec reactor you could not store 88M joules in the capacitors in one second. It would take a peroid of time to recharge.

With a smaller reactor at the same voltage you would have increased time even at the same voltage because you would need to decrease the current to satisfy Power = I*Voltage. ("I" being current, which is equal to Q/s). If your Q/s is reduced, then reaching you Qtotal needed to fire the weapon increases.

But long story short, there is no minimum size for the power source theorectically, only in the practical sense how having to recharge the weapon in a timely manner of minutes instead of days.

[Aanker]

How long does it take to reload a Tomahawk missile, and how many could you realistically store on-board? I'm thinking that at some point we also have to take into consideration that the railgun projectile could be smaller (no rocket fuel taking up space, I think?), so more could be stored on board for continuous fire.

[Magicman2051]

A kinetic energy weapon could easily be classified as a WMD. You asked about range Pheir, in terms of what? Effective or absolute?

[Sphere]

The question would be at what ranges does the rail gun become ineffective and to that I have no idea.

Get me the minimum "effective velocity" at impact and I could come up with an estimate. Perferably in Mach number which makes things much easier.