The pros and cons of DE weapons, electric propulsion, and other advanced electric powered systems.

Goals:

To find out what the advantages are of using directed energy weapons, electric propulsion, and electric powered systems like electro magnetic catapults. And to find out the down sizes, example;

Electro magnetic pulse bombs, and missiles, can disable directed energy weapons, and propulsion systems.

EMP weapon protection, how EMP protection works and how much is needed.


Purpose:

Because for one I can encorporate this knowledge in to my stories, and the intention of the project is to use the knowledge we gain in to future posts about the pros, and cons of these systems.

Members:

blue cell/Team Leader
devilwasp


Okay people here are the positions, I know devilwasp wants to do something about DE (directed energy) weapons, for some reason he has not been able to tell me if he wanted to do the good stuff about them, or the down sizes about them.

So right know here are the positions,


Pros of electric propulsion,
Cons of electric propulsion,
Electro Magnetic Pulse protection,
research on systems like the IPS (intergrated power system) and the electro magnetic catupult, and other systems that don't fit in the DE weapon category, or electric propulsion category.

Oh yeah I will do research on the IPS, and the other systems that don't fit in the other categories.


[edit on 28-6-2005 by ADVISOR]

[edit on 28-6-2005 by blue cell]

[edit on 28-6-2005 by blue cell]

Devilwasp want to do the cons of DE weapons, so the last position is


the pros of DE weapons.

Here is some material that should help you get started.

Electromagnetic Design of Diffractive, Micro-Cavity, and Photonic Band Gap Devices

[edit on 30-6-2005 by ADVISOR]

An electromagnetic pulse (EMP) is an electromagnetic shock wave that is given off by nuclear bombs, but can also be made to function solely as a weapon for the specific purpose of disabling electronics. The pulse lasts only for a few hundred nanoseconds, but the intensity of it can cause serious problems. Damage is severe, and can cause diasbling of electronic equipment hundreds of miles away from ground zero. In 1963, for example, a 1.4 megaton nuclear blast 250 miles above Johnston Island caused widespread power outages and the short-circuiting of 30 strings of street lights 800 miles away on the island of Oahu, Hawaii.

There are 3 types of EMP's: the surface-burst EMP (sbEMP), the high-altitude EMP (hEMP), the source region EMP (srEMP), and the specific region EMP (sprEMP).

sbEMP is the name given to an EMP blast that is detonated 1-2 Kilometers above the earth's surface. "The radiated wave is only propagated to a distance of ten to twenty kilometers from the burst point due to the higher density of the lower atmosphere. Although the area over which the low altitude EMP produces a damaging effect is relatively small, it is significant on the tactical nuclear battlefield"

The hEMP is the most damaging kind to electronics. This is an EMP detonated between 30-500 kilometers above the Earth's surface, and just one large nuclear blast 500 kilometers above the continental United States is enough to knock out all electronics in the entire country. A more in-depth explaination of the hEMP is given later.

The srEMP is detonated only a few hundred meters above the Earth's surface and the surge is localized only a few kilometers from the blast. "The generation of EMP by a surface blast begins with the gamma rays traveling radically outward from the burst. This action causes the Compton electrons to move radically outward and leaves behind immobile positive ions. This produces an electric field and lasts two to three nano seconds. The final result is a tremendous surge on current in the air on any communications equipment and the SREMP renders the equipment useless."

The last type, the sprEMP, is detonated in outer space and is directed towards satellites. The gamma and X-rays generated from a nuclear blast knock out electrons from the metal skins of the satellites, and generate an electromagnetic field that renders them and any milssiles that they guide useless. Althought the description of the hEMP below mentions a detonation from space, this is not to be confused with the sprEMP. The hEMP described below is on the fringes of the atmosphere, while the sprEMP is typically detonated farther out in space.


Below is a graph depicting the intensity and brevity of an electromagnetic wave from a nuclear blast compared to other sources of electromagnetic radiation:

Commercial computer equipment is particularly vulnerable to EMP effects, as it is largely built up of high density Metal Oxide Semiconductor (MOS) devices, which are very sensitive to exposure to high voltage transients. What is significant about MOS devices is that very little energy is required to permanently wound or destroy them, any voltage in typically in excess of tens of Volts can produce an effect termed gate breakdown which effectively destroys the device. Even if the pulse is not powerful enough to produce thermal damage, the power supply in the equipment will readily supply enough energy to complete the destructive process. Wounded devices may still function, but their reliability will be seriously impaired. Shielding electronics by equipment chassis provides only limited protection, as any cables running in and out of the equipment will behave very much like antennae, in effect guiding the high voltage transients into the equipment.

However, there are certain materials that are designed to 'harden' electronics from EMP's. Any conducting material will suffice, be it aluminum foil, copper, silicon, or conductive concrete. These enclose the electronics in a Faraday Cage of some sort, which is just a closed box that directs the pulse along its outside of the cage. It sounds counterintuitive to shield electronics with material that actually conducts the pulse, but the idea is to circulate it away from the electronics. The shielding is made to absorb the pulse, and let it circulate around or away from the sensitive material. For large structures, aluminum and conductive concrete will work, but for weaponry and other military equipment it makes sense to use lighter, more conductive materials that will therefore do their job and take up less space. For this reason, silicon is being pursued by the military:

Transtector’s EMP products are silicon-diode-based, which gives them advantages such as the nondegradable nature of silicon, he says; as long as the surge does not exceed the energy level of an EMP shot, the silicon will never degrade. Gas-tube devices have varying rates and degrade more quickly, Rebeck explains. Silicon also turns on quickly after the surge hits, Rebeck says.

the market for this type of technology is growing at about 10 percent every year and shows so much promise that Transtector officials have formed a new division around the military market and are looking at investing in an EMP testing laboratory on sight. Currently, the military market is only about 5 percent of Transtector’s business, but these investments show its leaders’ faith in this market.

Although these materials work very well to absorb and redirect the electromagnetic waves, they are only able to absorb a certain amount of energy. A major problem we could encounter would be a nuclear explosion in space. Although the blast is very far from Earth, and the laws of electromagnetism state that the intensity of the pulse weakens as distance from ground zero increases, the reaction of gamma radiation with earth's atmosphere produces large amounts of electromagnetic radiation:

The most "enhanced" EMP effects would occur if a nuclear weapon were exploded in space, outside the Earth's atmosphere. In such a case, the gamma radiation released during the flash cycle of the weapon would react with the upper layer of the earth's atmosphere and strip electrons free from the air molecules, producing electromagnetic radiation similar to broad-band radio waves (10 kHz-100 MHz) in the process. These electrons would follow the earth's magnetic field and quickly circle toward the ground where they would be finally dampened.

Tactically, a space-based nuclear attack has a lot going for it; the magnetic field of the earth tends to spread out EMP so much that just one 20-MT bomb exploded at an altitude of 200 miles could--in theory--blanket the continental US with the effects of EMP. It's believed that the electrical surge of the EMP from such an explosion would be strong enough to knock out much of the civilian electrical equipment over the whole country. Certainly this is a lot of "bang for the buck" and it would be foolish to think that a nuclear attack would be launched without taking advantage of the confusion a high-altitude explosion could create. Ditto with its use by terrorists should the technology to get such payloads into space become readily available to smaller countries and groups.

Because EMP's can be generated from a simple, non-explosive EMP generator, or a nuclear bomb of any size, the amount of EM radition varies largely. The energy of something like a hEMP blast however, detonated 500 Kilometers above the Earth would release an incredible amount of energy, around 25-50 kV/m. Research is under way to develop materials that can absorb this kind of EM radiation, and although it was hinted at that silicon diodes may be the way of the future, many specifics are still classified so it's hard to tell what is currently going on.

An 'EMP bomb':




www.abovetopsecret.com...

mae.pennnet.com...
www.globalsecurity.org...
www.aussurvivalist.com...
home.earthlink.net...
www.airpower.maxwell.af.mil...
www.tfd.chalmers.se...

[edit on 30-6-2005 by zhangmaster]
[EDIT to link ATS info]

[edit on 1-7-2005 by ADVISOR]

General information

The U.S. Navy is presently pursuing electromagnetic launch technology to replace the existing steam catapults on current and future aircraft carriers. The steam catapults are large, heavy, and operate without feedback control. They impart large transient loads to the airframe and are difficult and time consuming to maintain. The steam catapult is also approaching its operational limit with the present complement of naval aircraft. The inexorable trend towards heavier, faster aircraft will soon result in launch energy requirements that exceed the capability of the steam catapult. An electromagnetic launch system offers higher launch energy capability, as well as substantial improvements in areas other than performance. These include reduced weight, volume, and maintenance; and increased controllability, availability, reliability, and efficiency.




Pros of EMALS (electromagnetic aircraft launch system)

The introduction of EMALS would have an overall positive impact on the ship. The launch engine is capable of a high thrust density, as shown by the half scale model that demonstrated 1322 psi over its cross section. This is compared to the relatively low 450 psi of the steam catapult. The same is true with energy storage devices, which would be analogous to the steam catapult's steam accumulator. The low energy density of the steam accumulator would be replaced by high energy density flywheels. These flywheels provide energy densities of 28 KJ/KG. The increased densities would reduce the system's volume and would allow for more room for vital support equipment on the host platform.

Another advantage of EMALS is that it would reduce manning requirements by inspecting and troubleshooting itself. This would be a significant improvement over the present system, which requires substantial manual inspection and maintenance. The EMALS, however, will require a transition of expertise from mechanical to electrical/electronic.

EMALS eliminates the complexity of the present system's conglomeration of different subsystems. The steam catapult uses about 614 kg of steam for a launch, it uses hydraulics extensively, water for braking, and electromechanics. These subsystems, along with their associated pumps, motors, and control systems tend to complicate the launch system as a whole. With EMALS, launching, braking, and retraction would be achieved by the launch motor, thereby reducing all the auxiliary components and simplifying the overall system. The hydraulic oils, compressed air, etc. would be eliminated as well as the cylinder lubricating oil that is expelled into the environment with each shot. The EMALS would be a stand alone system, completely independent of the ship's main plant. This will allow greater flexibility in the design of the ship and more efficient ship propulsion schemes.

One of the major advantages of electromagnetic launch is the ability to integrate into the all electric ship. The Navy has directed substantial research into its Advanced Surface Machinery program that is developing electric derived propulsion schemes for the next generation of surface combatants. There has also been a good deal of work in high power electric weapon systems [1]-[3]. As such, more and more of a ship's systems will evolve into the electrical counterparts of old mechanical systems. This is true of the launch, and eventually, the arresting gear. The average power required by EMALS is only 6.35 MVA. Taking these power levels off the grid should not be a problem in an all electric ship, considering multimegawatt pumps already exist on carriers for various applications.

Perhaps the most interesting aspect of electromagnetic launch is the flexibility it offers in the way of future aircraft and ship designs. An electromagnetic launcher could easily be sized down to perform as a launch-assist system, augmenting the short takeoff of a STOVL aircraft. It can also be easily incorporated into the contour of a ramp, which provides a more efficient fly-away angle for the aircraft being launched. This reduces the required endspeed, the commensurate energy supplied, as well as the stresses on the airframe. Overall, an EM launcher offers a great deal of flexibility to future naval requirements and ship designs


The Downsizes of EMALS

On the other hand, there are drawbacks to the EMALS. One of these is that high power electromagnetic motors create electromagnetic interference (EMI) with electronic equipment. As in the case of an electromagnetic launcher, there would be sensitive aircraft equipment sitting directly above the launch motor. Along with the aircraft equipment is the ship's own equipment, which may be affected by the electromagnetic emissions. Through proper EMC design and a "magnetically closed" motor design, EMI will be minimized.

Another drawback of an electromagnetic launcher is the high speed rotating machinery associated with pulsed power applications. The disk alternator rotors are spinning at 6400 rpm, each storing 121 MJ, for a total of 484 MJ. In a laboratory, this is not a problem, but put these rotors on a heaving, jarring platform and it becomes more complicated. In order to ensure safe operation, the flywheel and bearings are to be a stiffer design than conventional.

Due to the inherent high level of elegant control of electronic equipment, it is possible to reduce the stresses imparted to the aircraft. The present steam catapult has relatively high peak-tomean acceleration profiles (nominally 1.25, with excursions up to 2.0). This results in high stresses in the airframe and generally poor performance. With an electromagnetic system it would be possible to correct for deviations in the acceleration profile in typically hundreds of milliseconds, which would result in low peak-tomeans. A simulation was conducted that analyzed the level of controllability of the proposed design. The acceleration profile is smooth and flat, compared with a typical steam catapult profile. The simulation shows that for various load conditions, the EMALS is capable of operating within the 1.05 max peak-to-mean acceleration requirement. The result of this reduced peak-to-mean is reduced stress on the airframe. To quantify the effects of a reduced peak-to-mean, a Fracture Mechanics analysis was conducted on the airframe [4] with both the steam catapult and EMALS peak-to-means. The results from this analysis show a peak airframe life extension of 31% due to the reduced stresses on the airframe. This is becoming more important as tight budgets are forcing the Navy to procure fewer aircraft. This also has the benefit of a safer operational environment, since when the EMALS experiences any unforeseen problems during a launch, it has the capability to quickly adjust and correct for them, even if a component fails during the launch


source

Other Links

company that is working on it website

www.house.gov... sreleases/107thcongress/02-02-20roberts.html




What this tells me is the key things the navy wants of future technolgies are reduced weight, volume, and maintenance; and increased controllability, availability, reliability, and efficiency. I think in some ways the whole military wants that, thats why were beginning to test EM (electromagnetic) armor for our vehicles. EM armor is a lot lighter then regular armor, but still offers a lot of protection, but the reasons of course are different. We want lighter vehicles for more speed, and deployabilty. Thats one of the major problems with the M1 Abrams, they can only fit like one on a C5 Globemaster. And thats where electricty comes in, the main pros of it are effiency, less maintenance because of that, which of course reduces crew size, which in turn saves the navy a lot of money, because of less salaries it has to pay. Thats why I think the US military of tommorow is gonna be able to deploy faster, because it smaller, more like a collection of strike groups. But I'll get some more links up here about how it works, and the machines involved.









[edit on 2-7-2005 by blue cell]

Okay guys I'm not going to be able to research on the EMALS, and the other systems like IPS. I'll research on the pros of DE weapons, who wants to take my place? U2 me if your intrested!

The Advanced Gun System (AGS) AGS is a 155mm Gun Weapon System planned for installation in the DD-21 Land-Attack Destroyers to provide high-volume, sustainable fires in support of amphibious operations and the joint land battle. AGS is a fully integrated gun weapon system that will include at least two separate gun systems for each DD-21 warship. Each gun system will be capable of independently firing up to 12 rounds per minute from an automated magazine storing as many as 750 rounds.
AGS will employ 155mm caliber munitions capable of hitting targets accurately up to a distance of 100 nautical miles.Associated with the gun are gunfire control functionality integrated into the DD 21 Total Ship Computing Environment (TSCE), an automated magazine, and low-radar and IR signatures for the gun and barrel. AGS design includes a family of 155mm extended range guided projectiles with warheads matched to the projected land attack target set. Efforts are underway to achieve as much commonality as possible with U.S. Army 155mm projectiles.

source


“AGS has a multiple round simultaneous impact capability to coordinate simultaneous delivery of multiple rounds,” says Scott Leitch, of United Defense, the AGS manufacturer. “You can fire six rounds, one right after the other, at the same target, with slightly different trajectories, so each round impacts the target at the same moment.The multiple round simultaneous impact capability can be used against targets up to 75 percent of the gun’s maximum range, says Leitch. For AGS, that means multiple rounds can be fired simultaneously at targets up to 75 nautical miles away.
other source


pdf about advanced gun system



Date In Service Planned introduction 2008

Projectile Types and Weights LRLAP - about 260 lbs. (118 kg)
Surface Attack Projectile - about 200 lbs. (90 kg)
Ballistic Projectiles - about 103 lbs. (46.7 kg)

Ammunition stowage per gun up to 750 rounds

Land Attack Guided Projectile About 100 nm (180 km)
Surface Attack Guided Projectile About 30 nm (55 km)
Ballistic Projectile About 22 nm (40 km



other source



Here are some pics











So the pro's I see in this system are no explosive charge needed to fire the gun . Automatic loading and firing, means less manning. And the full range of operations it can support, because of the full range of munitions it can fire. The the good thing about that is you have one ship, and one system that can support many operations. Something that will be very good, once our navy starts getting smaller. Those are the pros I see about this weapon, oh yeah of course its a lot cheaper then firing tomahawks. And you can get around the same range, and destructive power. Just a little not its not replacing tomahawks in any way, only in the inland fire support mission. So basically more bang for the buck!


Tell me what ya think of this people!

A railgun is a form of gun that converts electrical energy—rather than the more conventional chemical energy from an explosive propellant—into projectile kinetic energy



Railguns utilize an electromagnetic force termed "Lorentz force" to propel an electrically conductive projectile that is initially part of the current path. The current flowing through the rails sets up a magnetic field between them and through the projectile perpendicularly to the current in the rail. This results in a mutual repulsion of the rails and the acceleration of the projectile along them.

Railguns are being pursued as weapons with projectiles that do not contain explosives, but are given extremely high velocities: 3500m/s or more (for comparison, the M16 rifle has a muzzle speed of 975m/s), which would make their kinetic energy equal or superior to that of an explosive-filled shell of greater mass. This would allow more ammunition to be carried and eliminate the hazards of carrying explosives in a tank or battleship. Also, by firing at higher velocities railguns have greater range, less bullet drop and less wind drift.

Although full scale guns have been built and fired, including a very successful 90 mm bore, 9MJ kinetic energy gun developed by DARPA, they all suffer from extreme rail damage and need to be serviced after every shot. Rail and insulator ablation issues still need to be addressed before railguns can start to replace conventional weapons. Probably the most successful system was built by the UK's Defence Research Agency (now QinetiQ PLC) at a gun range in Kirkcudbright, Scotland. This system has now been operational for over 10 years, has an associated flight range for internal, intermediate, external and terminal ballistics, and is the holder of several mass and velocity records.
source


The advanced gun system is a rail gun if I didn't tell you in my last post. As you can see, a rail gun has many other military uses, besides inland fire support. There also working on a rail gun, and electro-thermal-chemical gun for a new artillary system that is part of the FCS family of vehicles. I believe with the power of the shells it can fire, this may be a suitable vehicle to support 82ND airborne operations. With the research into light but strong armor, they could make it light enough to be airdropped with the partroopers! These are just some of the amazing things I can think of that rail guns will be able to do in the future.

Originally posted by blue cell
Devilwasp want to do the cons of DE weapons, so the last position is


the pros of DE weapons.

Thanks, I'll do what I can when I can mate..

DE weapons,

The other members of this research group have already defined what DE weapons are, thier purposes, thier abilities and thier current uses in todays modern miltiaries. I instead , will hopefully describe the "Cons" Of DE weapons.

Rail guns;

As was explained earlier the rail gun uses electromagnetism to propel a round at high speeds, the cons to this weapon are quite many but simple.

The first major problem that happens in any energy transfer is energy losses more specifically heat, light and sound energy losses, these are the 3 main main problems affecting the effectiveness any weapon. The rail gun while profiding high velocity's is plagued with the problem of rail over heating. As you can imagine launching a 0.1 gram object at 16000m/s or around mach 47 will cause some incredible heat. The heat from the friction between the rail and the projectile or "slug" will cause barrels to bend and distort themselves, causing the weapon to be unsafe. This can be solved with the use of materials able to withstand high tempratures and the use of lubrication to reduce friction. Although the friction between the barrels and the slug is not the only problem, due to the slugs high speed through the air it literally "rips" the air apart, leaving a trail ofPlasma behind it.

The second major problem with rail gun technology in practicle usage is the problem of rate of fire. Its all well and good being able to fire something at 3.5 km per second but haveing to wait for atleast a minute to recharge the capacitor. Although the US navy has come up with the idea of haveing multiple capacitors therefore using one while the other recharges. Allowing the ship to have a decent rate of fire, capacitors will hold more and therefore need the number of them will decrease as technology adavances.

The third problem is that rail guns use quite a large , and I use the word lightly , to fire a round or slug off. Most rail guns are powered by land based generators which means the high ammount of power isnt as big as a problem as if you needed it at sea. Now the power supplied by modern warships frankly wont do with the rail gun technology. The solution to this problem is a bigger power source, the US navy has already got a ship in mind, the DDX , with the new power plants she will have the US navy believes she will be able to mount 2 155mm rail guns.

This ends my "research" so far...thank you for letting me prattle on and I bade you good night.



[edit on 26/02/2005 by devilwasp]

Electrothermal-Chemical (ETC) technology is an advanced gun propulsion candidate that can substantially increase gun performance with less system burden than any other advanced gun propulsion technology. It has been under development since the mid 1980s.

ETC uses electrical energy to augment and control the release of chemical energy from existing or new propellants, and can significantly improve the performance of existing conventional cannons, both direct fire (e.g., tanks) and indirect fire (e.g., howitzers and Navy guns). The electrical energy is used to create a high-temperature plasma, which in turn both ignites the propellants and controls the release of the chemical energy stored in the propellants during the ballistic cycle.
source





Okay that is the only link I found that I could really understand. Basically it uses the same principle as rail guns, kinetic energy, instead of using explosive powder to launch the projectile. And from what I've read, in tests it has used less electricty then rail guns.