Aotearoan and Greater German project.

[V The King]

OOC: Maybe I'm mixing things up, VM, but isn't that the formula for the object's Kinetic Energy? Meaning you're calculating how much energy it has after being fired, rather than finding how much energy needed in order to propel it.

EDIT: Wording.

Edited March 8, 2009 by V The King

[Vasili Markov]

OOC: Maybe I'm mixing things up, VM, but isn't that the formula for the object's Kinetic Energy? Meaning you're calculating how much energy it has after being fired, rather than finding how much energy needed in order to propel it.

EDIT: Wording.

I assumed the boost phase continued until impact.

If additional range is desired then energy will decrease according to the ballistics coefficient of the projectile (for reference 1.10 is the BC of a very-low-drag bullet.)

[LeVentNoir]

OOC: Ah, but you aren't scaling up a regular ship. You're changing the dimensions entirely; increasing the density to the point where it weighs more than the water it displaces. That is also known as a sinking ship.

OOC: First of all, in a linear scaling, density remains constant. Watch, multiply the mass by two, multiply the volume by two and the density remains the same.

OOC: LVN, the light gas gun is a research device, not a military device.

There is a military concept, but it's closer to a tank gun, rather than artillery.

OOC: If it fires at 5km/s + its only a matter of time. Second, the main force from the weapon comes from the scram cannon.

@ tashir re, do you think i'm firing thin straight up? try a 45 degree angle, and you still have no idea whats going on here.

@ VM, I have two tonnes of projectile, I'm sure some aerogel behind the uranium outer core will serve well.

@ KM, this is a research RP, not an announcing RP, so this is a great way to get feed back and change the design without being accused of godmoding. (first change being to shorten it to 600m.)

[Sumeragi]

OOC: If it fires at 5km/s + its only a matter of time. Second, the main force from the weapon comes from the scram cannon.

OOC: Please enlighten me on what makes an artillery an artillery. From what I see, the LLG would only be good as a AA or anti-tank.

[Vasili Markov]

OOC:

I think that the maximum practical time that a scramjet can be operated at that level of efficiency is 5 minutes at the most before the engine runs out of fuel. A scramjet eliminates the need to carry a separate tank of oxidiser for the rocket engine, you still need to carry a fuel tank.

5 * 60 = 300 seconds

300 seconds * 12 km/s = 3600 km (Slightly more than a tomahawk class cruise missile (2500 km) due to the using the space saved by removing the oxidiser tank for expanding the fuel tank) [or more if you allow it to coast but it will lose damage if it continues beyond this point]

For interest the velocity of a satellite in LEO is 8km/s so you may want to watch how you fire that thing or the projectile may never hit the ground EVER. (No high angle shots (greater than about 30' (I still need to do the maths on this one, but this is a guess)) or you may well put the warhead in orbit)

What you have is a fancy missile with about 1.44 times the range of a conventional missile and a kinetic warhead that will perform well at armour penetration (2 tonnes of DU @ 144GJ will probably penetrate most naval grade armour if a direct non-glancing hit can be achieved, this however can be defeated by introducing sloped armour to make a non-glancing hit harder to achieve).

Tl;dr: Not a super weapon, but a decent weapon system none the less.

[Malatose]

OOC:

I think that the maximum practical time that a scramjet can be operated at that level of efficiency is 5 minutes at the most before the engine runs out of fuel. A scramjet eliminates the need to carry a separate tank of oxidiser for the rocket engine, you still need to carry a fuel tank.

5 * 60 = 300 seconds

300 seconds * 12 km/s = 3600 km (Slightly more than a tomahawk class cruise missile (2500 km) due to the using the space saved by removing the oxidiser tank for expanding the fuel tank) [or more if you allow it to coast but it will lose damage if it continues beyond this point]

For interest the velocity of a satellite in LEO is 8km/s so you may want to watch how you fire that thing or the projectile may never hit the ground EVER. (No high angle shots (greater than about 30' (I still need to do the maths on this one, but this is a guess)) or you may well put the warhead in orbit)

What you have is a fancy missile with about 1.44 times the range of a conventional missile and a kinetic warhead that will perform well at armour penetration (2 tonnes of DU @ 144GJ will probably penetrate most naval grade armour if a direct non-glancing hit can be achieved, this however can be defeated by introducing sloped armour to make a non-glancing hit harder to achieve).

Tl;dr: Not a super weapon, but a decent weapon system none the less.

OOC: Also a good nuke launching platform..and it can probably shell cities from a certain distance.

[Malatose]

After careful consideration and much research, the Naval Research and Development Group "Behemoth" revamped the initial design for the ship entirely, presenting a more economical and feasable design.

Displacement: Approx. 145,000 tonnes

Length: 600m

Beam: 99m

Draft: 28.3m

Power Plant: 16 615.45 MW reactors [13,200,000 shp]

Additional Propulsion: 4 Waterjet, 2 Sprint Screws

Another set of technical specifications were also presented.

[Length:] 680 Meters

[Width:] 136 Meters

[Draft:] 13.6 Meters

Power Plant: 16 615.45 MW reactors [13,200,000 shp]

Additional Propulsion: 4 Waterjet, 2 Sprint Screws

These specifications were still subject to change, as research continued.

[Vasili Markov]

OOC: Also a good nuke launching platform..and it can probably shell cities from a certain distance.

OOC: And it would be just like a nuclear ICBM if used in that fashion, the only difference being that it would just have a shorter transit time than a normal nuke (probably still subject to SDI though).

And to address your second point would have a slight advantage in that you would be out of ground launched cruise missile range if you fired at maximum range at a coastal target , But not airborne or seaborne cruise missile launchers.

[Triyun]

OOC: Need additional support?

[LeVentNoir]

OOC: Lets take this point by point.

I think that the maximum practical time that a scramjet can be operated at that level of efficiency is 5 minutes at the most before the engine runs out of fuel. A scramjet eliminates the need to carry a separate tank of oxidiser for the rocket engine, you still need to carry a fuel tank.

The projectile does not fly under sustained power, it is boosted to that speed, then allowed to fly and fall under simple ballistic principals.

5 * 60 = 300 seconds

300 seconds * 12 km/s = 3600 km (Slightly more than a tomahawk class cruise missile (2500 km) due to the using the space saved by removing the oxidiser tank for expanding the fuel tank) [or more if you allow it to coast but it will lose damage if it continues beyond this point]

Thats assuming constant scramjet power, thinking it flys at ground level, and totaly ignoring newtons first law of motion.

First, the scramjet phase is over after it exits the tube. Then it acts like a large, and heavy bullet. Those don't stop moving just because they exit the gun do they? No, air resistance has a small part to play, but this will rise out of the atmosphere, curve around the earth in a ballistic arc (like a ICBM) and if it was initially moving at less than 11.2km/s (I can safely say air resistance will slow it down at least that much) it will come back to earth, somewhere on a line drawn right around the earth on the direction it was fired in. This is how you get the unlimited range. By using ballistic arcs. So more SS-25 than tomohawk.

For interest the velocity of a satellite in LEO is 8km/s so you may want to watch how you fire that thing or the projectile may never hit the ground EVER. (No high angle shots (greater than about 30' (I still need to do the maths on this one, but this is a guess)) or you may well put the warhead in orbit)

Escape velocity is 11.2km/s, we fire at 12km/s but that extra bit is to overcome air resistance. It will still be moving under escape velocity. Next, yes if we fire straight up we might hit a satellite, however, the chances of that is so low that you might as well ignore it.

What you have is a fancy missile with about 1.44 times the range of a conventional missile and a kinetic warhead that will perform well at armour penetration (2 tonnes of DU @ 144GJ will probably penetrate most naval grade armour if a direct non-glancing hit can be achieved, this however can be defeated by introducing sloped armour to make a non-glancing hit harder to achieve).

You greatly underestimate the energy this has. We know from today a 16MJ railgun can shoot through, well pretty much every naval armour around today, glancing or not. In CNRP, my 122.5MJ railguns have the ability to punch through any armour around here, glancing or not. This 144GJ weapon (with over 1000x the power of my railguns) will simply cause the ship to stop existing, or blast through a good couple of city blocks.

For reference, this is a weapon with the power of 119 tonnes of TNT, so it will remove a ship or a good chunk of a city.

Tl;dr: Not a super weapon, but a decent weapon system none the less.

Its pretty superweaponish, and if we put nukes on it, very.

OOC: And it would be just like a nuclear ICBM if used in that fashion, the only difference being that it would just have a shorter transit time than a normal nuke (probably still subject to SDI though).

Who has SDI defenses which can shoot down two tonnes of uranium moving at more than 10km/s?

And to address your second point would have a slight advantage in that you would be out of ground launched cruise missile range if you fired at maximum range at a coastal target , But not airborne or seaborne cruise missile launchers.

Considering this thing has a range of over 20,000 km, it is out of range of anything (subject to staying on earth etc), and hence perfect for shelling cities.

Edited March 8, 2009 by LeVentNoir

[Tahsir]

OOC: You know, I was going to mention all sorts of things that are wrong with this. But I'll just let the patent for the scram cannon speak for its own uselessness and the impossiblity of your scale of this cannon.

http://patft.uspto.gov/netacgi/nph-Parser?...p;RS=PN/4726279

Your tech level is about 2023. I doubt the issues facing large scaled versions like this will be solved in 14 years. I doubt even 20 years in the future the technology will exist to make one as big as you want this one to be. The only way it would be even remotely possible is it would need to be at least as big as project Bablyon was for the Iraqi's, and have just the same problems of utter uselessness in 99% of military use. The sheer cost to make a land based, immobile, version would be utterly useless compared to just making a big missle.

Like say..an ICBM?

[LeVentNoir]

OOC: Your tech level is about 2023. I doubt the issues facing large scaled versions like this will be solved in 14 years. I doubt even 20 years in the future the technology will exist to make one as big as you want this one to be. The only way it would be even remotely possible is it would need to be at least as big as project Bablyon was for the Iraqi's, and have just the same problems of utter uselessness in 99% of military use. The sheer cost to make a land based, immobile, version would be utterly useless compared to just making a big missle.

Like say..an ICBM?

OOC: Fail logic is indeed fail.

1. It is the size of project Babylon. But unlike that cannon, this is a mobile weapon, not something built on the side of a mountain, nor is it a conventional explosive power gun.

2. Its aimable due the fact it is on a ship. Ships can move and turn. This is not a weapon aimed at a fixed point.

3. try this link. Scram cannons have been around since mid nineties.

[Maelstrom Vortex]

ooc: Anyone wanting to build a mobile super gun platform really needs to read up on project HARP and why it failed.. because many of the reasons they will fail are directly related.

http://en.wikipedia.org/wiki/Project_HARP

[Tahsir]

OOC: LVN, if you read that patent, which, guess what, means that I know the idea of scram cannons has been around, its major downfall is there is nothing feasible to contain the pressures in the barrel for firing. Also Project babylon didn't promise "any point in the world" attack ability. It had under 1000km range, and hitting even a city was a lucky shot.

That article doesn't support any of your outlandish claims of the super power this gun has other than "it shoots a very fast shell".

Even your previous gartantuan ship wouldn't be able to handle the firing of your proposed gun specs. It would drive itself under the ocean if the barrel didn't explode first.

Edited March 9, 2009 by Tahsir Re

[LeVentNoir]

OOC: LVN, if you read that patent, which, guess what, means that I know the idea of scram cannons has been around, its major downfall is there is nothing feasible to contain the pressures in the barrel for firing

More logic and physics fail.

Point one. This is a scram cannon, not a gunpower based gun. There is no need to contain the pressure generated from the combustion of the fuel, we just vent it all out the back.

Also Project babylon didn't promise "any point in the world" attack ability. It had under 1000km range, and hitting even a city was a lucky shot.

That article doesn't support any of your outlandish claims of the super power this gun has other than "it shoots a very fast shell".

You don't know nothing about ballisitcs do you? The faster a projectile moves, the longer range it has. Project babalyon was lucky to get maybe 1500m/s, we are going to get 12,000 m/s. Go do high school physics.

Even your previous gartantuan ship wouldn't be able to handle the firing of your proposed gun specs. It would drive itself under the ocean if the barrel didn't explode first.

As stated above, a scram cannon has no recoil, and so it would not do that. And why would the barrel explode?

ooc: Anyone wanting to build a mobile super gun platform really needs to read up on project HARP and why it failed.. because many of the reasons they will fail are directly related.

http://en.wikipedia.org/wiki/Project_HARP

Gunpower based system, this is a scram cannon, different physics. Like for one, we don't have a upper limit for the speed we can get a projectile moving at.

Edited March 9, 2009 by LeVentNoir

[Manetheren]

If anything you could use the firing of the gun as a propulsion system for the ship. The "recoil" is being vented out the back, which, to avoid huge pressure would have to be done quickly, thus essentially forming a jet engine. Something to consider at least. Of course you could have the recoil gasses be carried by pipe in every direction, stabilizing the ship

[LeVentNoir]

If anything you could use the firing of the gun as a propulsion system for the ship. The "recoil" is being vented out the back, which, to avoid huge pressure would have to be done quickly, thus essentially forming a jet engine. Something to consider at least. Of course you could have the recoil gasses be carried by pipe in every direction, stabilizing the ship

ooc: Actually it wouldn't because the bit of the ship the gas is pushing against is accelerating forwards quickly; ie the projectile. The rest of the ship experiances no force.

[Tahsir]

OOC:

The patent link::::::::::::::READING FAIL

Wake stabilized supersonic combustion ram cannon

Abstract

A supersonic combustion ram cannon (1) includes a conical projectile (8) with a flat base (9) which produces a subsonic wake (12) as it flies through a barrel (2). The projectile is configured to avoid a normal shock, relying instead on supersonic compression, combustion and gas expansion. The supersonic combustion of a fuel-oxidizer mixture around the tail of the subsonic wake, pressurizes the wake and drives the projectile forward. By utilizing wake stabilized supersonic combustion, the compression and combustion pressures can be matched to the limiting barrel working pressure, thereby providing for optimum thrust and maximum projectile acceleration.

What does that say LVN? Looks like a SCRAM cannon? Why I think it is the patent for a SCRAM cannon.

Golly ge-whillikers. You mean I posted a link to a actualy SCRAM cannon and not a gunpowder cannon?

Yes

oh and what is this? Vent it out the back? Whoops failure on the homefront!

A particular problem with subsonic combustion ram cannons is that such ramjet propulsion of a projectile within a gun barrel generates a rapid pressure build up during the projectile acceleration. A normal shock wave slows the flowing gas to subsonic velocities prior to combustion and induces a high pressure gradient directed to the barrel wall. It is at this point in the ramjet cycle that the peak pressure is encountered. Since the ram cannon design is limited by the barrel working pressure, a subsonic combustion ram cannon must be designed for the shock pressure. Consequently, the maximum muzzle velocity of the projectile is limited by the pressure rating of the barrel relative to the high pressure spike that occurs at the point of normal shock.

what? MOARRRRR?

Utilizing supersonic combustion (see FIG. 2c) in a ram cannon has been investigated as a method of avoiding a normal shock and the concomitant high pressure peak. However, such supersonic combustion ram cannons include a tail section which confines the combustion area, leading to the build up of high pressure gradients in the combustion zone. Eventually, at high velocity, the supersonic combustion zone will narrow until an oblique detonation wave forms (see FIG. 2d), providing a very narrow reaction zone, similar to the normal shock wave. Since this pressure cannot exceed the barrel limiting pressure, the high pressures generated with the oblique detonation wave effectively limits the potential thrust.

look! Another problem I havn't even addressed yet! Glory be!

Another problem with subsonic combustion ram cannons involves the possibility of propagating a detonation wave ahead of the moving projectile into the unburned fuel-oxidizer mixture, resulting in a preignition of the fuel-oxidizer mixture, halting acceleration of the projectile.

And guess what? "Just make it bigger" doesn't fix these problems!

Tell me, how was high school english class since you were to busy with highschool physics?

[LeVentNoir]

OOC:<snip>

ooc;I did link you to a page about working scram cannons..... Which consequently proves all your points are either trival / already have been solved.

A scram cannon was found to work perfectly well with an unsealed rear end, the barrel held the pressure at the point of combustion, and a fuel oxidier mix that did not run up the tube was found.

Scram cannons work, and if you don't like it, please, get out of here.

[Tahsir]

OOC: LVN I have no problem at all with small scale SCRAM cannons. You're talking about a super massive cannon that is an impossiblity at the size you want it.

"Just make it bigger" doesn't work with any type of gun, ever.

Edt add on: Also if they have working small scale SCRAM cannons since 1994, and the patent link I give is from 1986, then tell me. Why in 2009 there isnt even ONE military SCRAM cannon in exsistance? infact the only "military" references to large SCRAM cannons is just what wiki said about then. In Science Fiction.

Edited March 9, 2009 by Tahsir Re

[Uberstein]

ooc;I did link you to a page about working scram cannons..... Which consequently proves all your points are either trival / already have been solved.

A scram cannon was found to work perfectly well with an unsealed rear end, the barrel held the pressure at the point of combustion, and a fuel oxidier mix that did not run up the tube was found.

Scram cannons work, and if you don't like it, please, get out of here.

And where is YOUR evidence? I find it incredibly odd how he is providing evidence and you aren't. I don't see a single patent link, a single article, or even any math in your post! You're just saying it works without any reason why we should believe you besides anecdotal "I know physics."

[Shadowsage]

OOC: Considering the burden of proof is on LVN, I do believe Tashir Re has proven the concept to be ludicrous, at best and an insane concept to boot.

[Vasili Markov]

OOC: I have found some real life examples of scramjet powered vehicles (AKA: I just found out more than I really wanted to know about scramjets)

Rockwell X-30

Specifications:

* Proposed Maximum speed: Mach 30, (20,000 mph, 32,000 km/h) (Never achieved, no working prototype)

* Total Mass: 300,000 lb (140,000 kg)

* Empty Mass: 132,000 lb (60,000 kg)

* Development Cost: US$ 3,000 million in 1985 average

* Project status: Scrapped (continued with X-43 & X51 research) ,

* Prototype: No working prototype ever built, considered a failure but important discoveries were made that allowed the X-43 & X-51 programs to begin.

NASA/Boeing X-43

* Maximum Speed: Mach 9.68

* Mass: 3000lb (1300kg)

* Development cost: US$230 million over 7 years (Phase I only)

* Project status: ongoing

* Prototype: Yes

Boeing X-51

Specifications:

* Length: 26 ft in (7.9 m)

* Empty weight: 4,000 lb (1,814 kg)

* Maximum speed: Mach 7+

* development cost: $246 million 1

* project status: ongoing

* Prototype: Yes

Current Scramjet research programs.

X-15

* Developer: USAF

* Top speed achieved: Mach 6.7

SCRAM

* Developer: Johns Hopkins Applied Physics Laboratory

* Top speed achieved: Mach 7

NASP (Project Copper Canyon)

* Developer: DARPA

* Findings: Mach 17 concluded as theoretical limit of scramjet technology

HyShot

* Developer: University of Queensland

* Top speed achieved: Mach 7.6

Hyper-X (X-43 program)

* Developer: NASA

* Top speed achieved: Mach 9.68 (Mach 15 Proposed limit for X-43D)

FASTT

* Developer: Alliant Techsystems

* Top speed achieved: Mach 5.5

Russian millitary (GLL Holod program)

* Developer: Russian millitary

* Top speed achieved: Mach 6.5?

So based off current research, a scramjet engine will be able to achieve a speed of Mach 9.68 with a theoretical limit of Mach 17. Not Mach 30+ ,The X-30 program was scrapped as unworkable and smaller and slower planes were developed off the research data gathered from that program.

And in game terms I would say that this would be a major research program that will cost many billions of dollars and take several years to develop a workable weapon. For a real world example of this consider that the US military with almost unlimited funding has taken since the 60's to get to the point it is at now.

[LeVentNoir]

OOC: I have found some real life examples of scramjet powered vehicles (AKA: I just found out more than I really wanted to know about scramjets)

<snip>

So based off current research, a scramjet engine will be able to achieve a speed of Mach 9.68 with a theoretical limit of Mach 17. Not Mach 30+ ,The X-30 program was scrapped as unworkable and smaller and slower planes were developed off the research data gathered from that program.

And in game terms I would say that this would be a major research program that will cost many billions of dollars and take several years to develop a workable weapon. For a real world example of this consider that the US military with almost unlimited funding has taken since the 60's to get to the point it is at now.

OOC: These are examples of planes, flying in air, battling air resistance, There is no air resistance in the tube, and indeed the fluid in there provides more energy. The impact speed will not be 12km/s, there are two lots of air resistance to go through (launch and re entry), so it will hit a bit slower, however, it will still be devastating. I am not claiming this weapon travels through air under its own power at 12km/s, just that thats the exist speed.

OOC: LVN I have no problem at all with small scale SCRAM cannons. You're talking about a super massive cannon that is an impossiblity at the size you want it.

"Just make it bigger" doesn't work with any type of gun, ever.

Edt add on: Also if they have working small scale SCRAM cannons since 1994, and the patent link I give is from 1986, then tell me. Why in 2009 there isnt even ONE military SCRAM cannon in exsistance? infact the only "military" references to large SCRAM cannons is just what wiki said about then. In Science Fiction.

Um this is firing a small, 50L volume projectile, with a estimated bore of 60cm. The nice thing about scram cannons is that you do not need more pressure for a larger projectile, it is a engine, not an explosion. It will just accelerate more slowly, so a longer tube is needed, and we do have a longer tube.

I think I answered all you other problems on IRC.

[LeVentNoir]

OOC: I just realised, why do I have to prove it will work, I'll just make the damn thing and let maltose explain it.

I'm never going to use it, so no skin off mu back if it doesn't work.