[CanRay]

Room-sized, huh?  Bet that'd fit on a Battleship pretty easily.

Or put one on the nose of a Nuclear-Powered Carrier and you got some armament for it...  Just make sure you book ahead a week in advance to get it on target. 

[JustADude]

Room-sized, huh?  Bet that'd fit on a Battleship pretty easily.

Or put one on the nose of a Nuclear-Powered Carrier and you got some armament for it...  Just make sure you book ahead a week in advance to get it on target. 

"Room-Sized" was apparently an earlier prototype that was declassified in 2010. The new one is no more bulky than the current 406mm guns they use on Iowa-Class battleships right now.

And I'm pretty sure, given it's the Navy testing them,  that's exactly where they're going... Iowa-Class battleships.

Here's a finely crafted link.

... ... ...

And, on reviewing the video, it looks like it's more of a giant "muzzle flash" than a "plasma trail". The camera angle on the original footage I saw was rather misleading, in that regard.

However, notice that there is a very noticeable flash when the projectile, which uses no form of chemical propellant, leaves the barrel. It might not be a full-blown plasma wake, which is very likely to get more and more noticeable as the speed of the round goes up.

[Xzylvador]

The "gun" is still smaller, but afaik, with current technology you still need room- (well, small house-) sized batteries and capacitators or whatchacallits to store and release that much power in a microsecond.
Of course, by 2070 we've finally made some real leaps in this kind of technology and it all fits in a simple battery pack.

[_Pax_]

As for th giant plasma trail ... I'll point out that the Navy is using railguns, not coilguns.  In a railgun, the projectile is in quite firm contact with two electrically charged rails (and the charge crosses from one to the other, through the projectile).  Between the friction of moving along those rails, and the heating of passing a large charge across the projectile .... well, the "muzzle flash" we see, is probably from part of the projectile actually vaporising while being fired, and not a direct atmospheric interaction.

The Thunderstruck, meanwhile, is described as a "gauss" weapon, strongly implying it is in fact a coilgun.  Coilguns do not have any greater contact between the projectile and the barrel than ordinary firearms do - and potentially, quite a deal LESS, all the way up to zero contact.

Additionally, it is entirely possible that the Navy's prototype is using an evacuated barrel (that is, one in which a vacuum exists), sealed by a plasma window ... and the plasma trail we see, is the result of a highly-magnetically-charged projectile disrupting the window's containment field, while simultaneously pulling a great deal of that plasma along with it.  IOW, they may be "shooting through a wall of dense fire".

[TheNarrator]

And I'm pretty sure, given it's the Navy testing them,  that's exactly where they're going... Iowa-Class battleships.

I've heard that it's going on a new all-electric warship. (The Freedom-class, perhaps?) The Iowa-class battleships have all been retired and turned into museums.

[Mirikon]

... they would have to be going so stupendously hypersonic to do that (leaving a high-energy ionised trail through the air), that their damage code and AP would both simply read "Yes".

9P, Halve all but smart armor, then -4 AP sounds pretty much like "Yes" to me. Against anything smaller than a tank, that's an instant kill.

I mean, this is coming from a projectile of very little mass, relative to the things it hits. Even if the kinetic energy impacts like high explosives, it is still a relatively small area receiving the initial impact. It is the same idea as a Thor shot: Mass A goes real fast, hits Mass B, things go boom. The difference is that the Thunderstruck round is significantly smaller than even the individual spikes from a Loki canister, and instead of a gravity-powered, orbital drop weapon, you have an electric-powered, horizontally fired weapon.

[_Pax_]

... they would have to be going so stupendously hypersonic to do that (leaving a high-energy ionised trail through the air), that their damage code and AP would both simply read "Yes".

9P, Halve all but smart armor, then -4 AP sounds pretty much like "Yes" to me. Against anything smaller than a tank, that's an instant kill.

  No, not really.

  GMC Hermes cargo van, body 17.  Give it Concealed Armor 10.  So, sure, sure, the Thunderstruck halves that 10 to 5, then chops that down further to 1.

  That still leaves 18 dice to resist the damage.  One shot is not going to pop the whole vehicle.  Two, still unlikely (but more realistically possible).

  Same truck, but with glaringly-obvious armor (Standard at 20, Smart at 10) ...?  The Smart Armor will probably cut the AP from -4 to -1.  Half of the total 30 points of armor is 15; minus 1, plus the Body, is 31 dice to resist the damage.  You're gonna be emptying the clip, and maybe some of the next clip, to take THAT down.

...

That is not a damage code of "yes".  Thor missiles have a damage code of "yes".

I mean, this is coming from a projectile of very little mass, relative to the things it hits. Even if the kinetic energy impacts like high explosives, it is still a relatively small area receiving the initial impact. It is the same idea as a Thor shot: Mass A goes real fast, hits Mass B, things go boom. The difference is that the Thunderstruck round is significantly smaller than even the individual spikes from a Loki canister, and instead of a gravity-powered, orbital drop weapon, you have an electric-powered, horizontally fired weapon.

  And still not moving so fast as to leave a trail of ionised plasma through the air.

[FlyDog]

You want the Thunderstruck so you can say, "Kneel before the Hammer of Thor!" as the discharge crackles off of your sunglasses.