Talk-Polywell.org

I would point out that these things will create quite the shockwave when they hit, so a pile of them coming in will be very discouraging to infantry. At extreme range they'd be an area affect weapon anyway.

Also, these will be packing a bit more energy than a 100mm/5 inch gun, so you don't need so many. The fire rate isn't so much number of rounds on target, but the energy on target. High ROF will do that, but a bigger gun with a bigger "bullet" will too.

US Navy is already shooting their third generation of guided rounds from their 5" guns. This is important when trying to hit a ship, and necessary when trying to hit a tank. The rail guns are not shooting molten anything. The projectile would fly apart if it were molten. They're currently shooting solid block penetrators, which are fine for hitting ships but guided they're much more deadly. And yes, I'm pretty sure the current 5" guns are capable to shoot high explosive rounds against infantry. This is one of the biggest points for a gun that shoots 110 miles--it can be used like artillery without all the logistical support of moving Paladins into a conflict area.

Last I recall we used ships for artillery was in the early 80's in Lebanon, the USS New Jersey kicked as with her 16" monster cannons. I think they had a range of something like 23 miles. During the Lebanese conflict, the New Jersey was criticized for missing it's target at times up to 10,000'. That doesn't happen with modern, guided rounds. Also, IIRC, the current 5" guns have air-burst for anti-aircraft functions. USN might let that go with their missile ability, but I don't see much hope they'd settle for only solid penetrators. They really do need guidance and high explosive functions on a working railgun system.

Also note, the current 5" guns have a fire rate of 20 rounds/minute, so when the Navy says they need 10 rounds/minute from the railguns, they're already counting on more energy on target.

ScottL wrote:

GIThruster wrote:Pretty sure Raytheon is also in the competition, so there are 3 vendors, and they're testing up to 33 MJ. I would not however, expect them to be retrofitting anything until they have a few years work on the projectiles themselves. Though they're no longer falling apart, they are still solid lumps of metal and not a replacement for the kinds of munitions we currently have. For instance, without a high explosive round, the gun is not much use against infantry, so that 110 mile range is not put to much use. They need to develop the same sorts of guidance we currently have for it to be used against ships, tanks, bunkers, etc. The current guidance systems would be squished to mush by a 5MJ shot. Also, they need to be getting about 10 shots/minute, and I haven't seen any data on that yet. Probably needs active cooling that none of the pre-prototypes include. And there is the trouble that most of the ships that it is intended for, will need serious generator upgrades if they're going to generate enough power to fire 33 MJ at 10X/minute. I'm not sure we'll see these weapons installed for another half decade. To fit the ships that already have the higher generator capacity like the Littoral ships, you'd likely need a smaller gun.

Guidance on the equivalent of a bullet? This thing isn't shooting rockets, the whole point is to send a slag of molten metal at high speed. It's not about taking out tons of troops, it's about putting a hole in a building/bunker/ship. If you want guidance, stick to missiles and rockets...etc.

Guided bullets are interesting. Sandia has reportedly developed a guidance system for machine gun bullets.
http://news.yahoo.com/sandia-labs-engin ... 45833.html
I expect that soon enough, someone will develop a guidance system for rail gun slugs.

GIThruster is right, I am pretty sure the navy is using passively guided artillery shells.

GIT said the navy is on Gen III Guided rounds.

I can assure you that the navy operationally shoots no guided rounds from 5inch 54 or 62.

As far as down range effects. For railgun, submunition dispensers have already been tested. Viola, soft and multiple target engagement.

You do not have to have a bursting round for effects. You can have a submunition ejector, that sprays sub 'splinters' of tungsten mini-rods over an area. Very lethal, very effective, very tested. No electronics neccessarily involved, a simple setback mechanical timer could do it. But, to be more fancy, you can mix in a VT proximity or other, if you wish. The navy has been using electronics in fired rounds since WWII. They work just fine. The navy has also used guided Rocket Assisted Projectile rounds, including down to 5 inch since WWII. They survive crazy g-force just fine. The navy has also done RAP from 16 inch, just fine, with guidance packages. Again, absolutely crazy G's. The last go round with RAP(ERGM) for 5 inch did not go so well. It was more an issue of quality verses cost from the vendors. They let cost go silly, and the navy said pass. Nobody has called the vendors on WTF regarding previous perfectly successful RAP and purely kinetic guidance packages. As another example, the army has had a long and proud continuous history with electronically guided 155 and 255mm rounds. Why did the navy ERGM vendor struggle? Simple...greed.

GIT, you know about some good stuff, but this is my lane. You are out of your depth here. Random point to make mine, did you know that WWII Fletcher Class Destroyers had an optical range finder centered at 46 feet 8 and 5/8 inches above waterline? I guess not. You may want to wonder why or how I do, and then leave it be.

Final point, Railgun INP Phase II into III also includes rate of fire testing, to include ringing out the PFN's. The GA package is actually supportable on current platforms. You cite issues with LCS. I say you (GIT) are uninformed in regard to LCS square and cube. I can put a GA Railgun on either LCS tomorrow and fire rounds. Give me a year, and I can demo an LCS trainable mount that can hit things with repeating fire.

Cheers.

P.S. Yes Ratheon is on the list, but has not produced a test article unlike BAE and GA.

I seriously can't wait to see footage of live trials or actual use. Maybe impact won't be too spectacular, but just knowing what you're seeing'll make it so damned cool anyway.

Iadajo is right to correct me on some of my statements. I should have said that US Navy is on their 3rd decade of guided munitions, not 3rd gen guided shots.

Just saying though, I have read about each of these issues that I've noted here. Railgun projectiles have not yet been refined to the point they can replace standard 5" guns, and until the gun can fire smart projectiles, they won't be put into service. According to the Navy, the conditions these hypersonic projectiles have to endure preclude using electronics similar to what has been used in the past for smart munitions.

Also according to the Navy, they will most likely need to install more power generation in the Arleigh Burke class destroyers the rail gun is intended for. Makes perfect sense. If you're firing 33MJ at 10X/minute, you need to generate 5.5 MW and that's not something the Arleigh Burkes were designed for.

Also according to the Navy, they have not seen the barrel repetition testing nor fire rate testing they need for a real prototype. They have tested barrels to 100 shots so far. The current 5" guns get 500-600 shots on a much cheaper barrel.

Pretty sure I read that no one at the Navy expects these guns to get their first sea trials until 2019.

BTW, now that I think of it, I think Raytheon is providing the power systems, not the actual guns.

40 plus years.

http://www.telegraph.co.uk/news/worldne ... l-gun.html

Yeah Team!

Although, as discussed we are a ways from feilding a full-up fleet system. GIT was perfectly right to point out above that rate of fire power generation is still an issue. Existing combatant hulls do not have the organic generator depth to support. However, it would be possible to float a system on hulls with larger 'cargo' capacity than traditional CruDes with non-organic generation assets as a "temp" plus up.

Imagine putting a gun or tow on the flight deck of an LSD, with trailered or containered gas turbine unints in the well deck driving a PFN. You could even do something on an LCS, there is enough room on the Tri-hull (Independance) for sure.

http://www.wired.com/dangerroom/2012/02 ... -real-gun/

ladajo wrote: http://www.telegraph.co.uk/news/worldne ... l-gun.html

Yeah Team!

Although, as discussed we are a ways from feilding a full-up fleet system. GIT was perfectly right to point out above that rate of fire power generation is still an issue. Existing combatant hulls do not have the organic generator depth to support. However, it would be possible to float a system on hulls with larger 'cargo' capacity than traditional CruDes with non-organic generation assets as a "temp" plus up.

Imagine putting a gun or tow on the flight deck of an LSD, with trailered or containered gas turbine unints in the well deck driving a PFN. You could even do something on an LCS, there is enough room on the Tri-hull (Independance) for sure.

http://www.wired.com/dangerroom/2012/02 ... -real-gun/

Awesome! We are the bad asses of the sea!

The ability to shoot so far is going to be highly sought after by all US allies. Though I doubt anyone in Europe would buy a US destroyer, they'll probably all want access to this gun for their own destroyers.

I'm surprised there's no scuttlebutt concerning a smaller version for the Littoral ships. One would think smaller would be cheaper and easier to build, especially if is was shooting at Mach 5 instead of Mach 7.

I have wondered that myself.
But I am also aware that the primary driver has been years of the Marine Corps calling out the navy for dropping the ball on Naval Gunfire, or NSFS as we say...
Sadly, Navy ships have not mounted main batteries as a primary Anti-Surface system. It is for supporting fires. But, for years the navy has relied on the 5 inch series, which to be "fair" actually suck at gunfire support. Not enough range, and not enough hitting power for anything but soft targets. You can toss plenty of rounds down range, but they do not hit hard. For sft stuff like unharded structures and troops or minimally armored vehicles, it is ok. As long as the gunline is not where it puts the ship at risk, which with the ranges for 5 inch 54/62 is shaky at best.

http://www.foxnews.com/scitech/2011/01/ ... test=faces
This is a year old, haven't heard anything lately. Anyone else have? Even greater potential than the railgun for anti-missile defense for our ships.

Just found this; Crap! what were they thinking:
http://www.wired.com/dangerroom/2011/06 ... r-railgun/
Hope this doesn't stand, but given the defense cuts looming anyway it probably will.