The Railgun!

[Legend]

The Railgun has caught my attention recently, and while digging through numerous amounts of articles, I stumbled upon this one:
http://www.defenseindustrydaily.com/fil ... G-1000.pdf
Which I believe the BB lovers on here (me included) will like some of the conclusions drawn about the current state of our little 5in mk45 capabilities.

Over the past week I have been looking over the numbers of the current prototypes and potential final production models of the Railguns being developed by the USN in collaboration with private companies. The possibilities of this system seem very... formidable, and are worth the consideration of many in the Naval community. I am going to a funeral this weekend and will be back next week, but I hope that some developments here will be made.

Best Regards,
Legend

http://en.wikipedia.org/wiki/Railgun
http://www.popularmechanics.com/technol ... 31461.html
http://www.chips.navy.mil/archives/07_J ... ilgun.html

[Kyler]

Here's the model of the BAe 64Mj Railgun they are developing for the Navy







Here's the article where the pictures came from
http://www.defenseindustrydaily.com/bae ... pon-01986/

Interesting info about the Navy considering building new capital ships to handle the railguns.
I created a similar post saying the navy was and still is considering making new battleships just for railguns. Your
article proves my assumption correct. Thanks

[lwd]

It should be noted that em guns can come in at least two distinct flavors: rail guns and coil guns. I remeber a conversation with an individual deeply involved in cannon design and construction a decade or so ago and he made a very strong case for a hybrid coil gun being the best near term option. You might want to broden your search a bit if you are interested.

[Legend]

May I inquire the difference between Railguns and Coilguns? I have an idea what the difference is but I would rather have it better set out from a more definitive point of view to set my position straight.

So they are contemplating a large scale warship to mount a LARGER railgun than the envisioned 6.1in? (what I assume the 15kg, 64MJ system will have a caliber of). A 16in Railgun would have an EXTREME penetration capability! If I read the evaluation document correctly they were considering the possibilities of a 16in railgun!?! If a 33 pound railgun round has around the same destructive capabilities as a conventional 2,700 pound BB round... then imagine what a, say around 1500-2000 pound RAILGUN round can do? They said that the 5in gun doesnt have ideal capabilities... but would a railgun that size be overkill? Not to mention the amount of power it would take to propel that monster round!

[lwd]

May I inquire the difference between Railguns and Coilguns? I have an idea what the difference is but I would rather have it better set out from a more definitive point of view to set my position straight....

In a rail gun the projectile rides a magnetic pulse down two parallel rails. In a coil gun the "barrel" has a helical coil that accelerates the projectile. I'm not all that up on the differences myself. Supposedly coil guns are very good at taking a projectile that is already moving at a decent speed and getting it to move much faster. Thus the hybrid approach. Use a relativly small explosive charge to get the shell moving at a decent speed then the coil takes over. I think coil guns also are easier to make with longer lasting barrals but could be worng there. I know the first rail guns were one shot afairs as firing "ate up" the rail and even later ones couldn't fir very many shots without replacing the rails.

[Legend]

Ah! I see now! Thank you my friend. That makes this matter very clear now. I could only wonder why the coilgun is no good at acceleration, if they could fix that then it would be the better of the two systems for sure... Okay I see the problem now. The coilgun should theoretically be a more powerful accelerator (which it is) because of the helical coils giving the electromagnetic field more surface area around the barrel... but then that would mean the continuous coil down the barrel would mean that wherever the projectile is in the barrel, it has the same amount of electromagnetic force worked upon it. Thus the railgun implementation is necessary to get it moving. Perhaps if the railgun portion is still causing wear problems they could test out how a pure coilgun would work...

[lwd]

It's been a long time since I studied them and I never did in any great detail. I recommend further research before you rely to much on my sometimes foggy memory.

[Legend]

My greatest question is how the great electromagnetic charge that is sent down the barrel is neutralized so it doesnt decelerate the acceleration of the projectile? I cant think of a way that it would just discharge at the end of the barrel... and if you sent it back down the barrel it would work against the existing, purpose made, electromagnetic field.

Unless of course by the time it got to the end of the barrel the potency of the charge was depleted and sending it back down didnt do anything...

Unless I am thinking about it wrong and any electromagnetic field, will accelerate the projectile... That would make sense too.


Please excuse my ignorance in this subject and understand I am fairly young and persuing the knowledge of our modern technological advances.

[lwd]

Some substances resits magnetic fields. Thus if a magnetic field is generated there is pressure on the object to move away from the field. Some of the early demonstrations of super conductivity involed a sphere of lead (I think) being suspended over a super conducting ring. A change in current flow produces a magnetic field.