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Metal Gear Wiki

A man-portable rail gun.

A rail gun is a device which employs electromagnetic induction rather than expanding gas or mechanical action to accelerate projectiles.


Peace Walker Incident

Main article: Peace Walker Incident

The Chrysalis UAV, armed with a rail gun.

In 1974, a rail gun was used by the Chrysalis AI weapon, which was destroyed by Big Boss. After it was defeated, Big Boss and the Militaires Sans Frontières salvaged its rail gun, as well as its radome, to build Metal Gear ZEKE.

A man-portable version was also developed by the MSF. It required a separate exterior dynamo that employed an experimental microwave power transmission mechanism (which was under similar development in other countries), and at least two people to operate it due to its large consumption of electricity. There was also research being conducted on rail gun technology throughout the developed world during this time.[1]

The Phantom Pain

During the 1980s, the same rail gun dynamo technology that the MSF had engineered was used by the Diamond Dogs to torture Quiet. In addition, Metal Gear Sahelanthropus had a rail-gun included among its armament.

Post-Phantom Pain

The rail gun technology was further developed for the Strategic Defense Initiative (SDI), but was later scrapped. In 1993, rail gun testing was restarted,[2] eventually culminating in the technology's advancement in the early 2000s, as the result of a joint venture between ArmsTech and Livermore National Labs.[3]

Shadow Moses Incident

Main article: Shadow Moses Incident

Metal Gear REX, equipped with a rail gun designed to launch nuclear warheads.

Metal Gear REX was equipped with a rail gun on its right shoulder, which was ostensibly designed to provide it with missile defense capabilities. However, it was actually designed by ArmsTech to enable it to launch stealth equipped nuclear weapons, without the chief designer's knowledge. By using a rail gun rather than rocket propellent, a warhead could be launched that would be undetectable. This also exploited a specific loophole that existed in anti-nuke treaties, since weapons fired from a rail gun were not technically ballistic, so limitations on ballistic weaponry did not apply. A country could therefore use REX to secretly attack any desired target without fear of retaliation through military or legal force. ArmsTech president Kenneth Baker was aware that the warhead delivery system, had it been made public, would have resulted in the weapons manufacturing company being shut down, and with him facing a costly inquiry.[4]

During the Shadow Moses Incident, Baker entrusted an MO disc containing REX's test data to Solid Snake, in order to get it to Secretary of Defense Jim Houseman. During REX's development, the rail gun technology had demonstrated serious issues with targeting accuracy, although tests conducted on Shadow Moses Island had proven successful, making the data invaluable to the Pentagon.[5] Snake was successful in disabling REX at Shadow Moses, after it had been hijacked by terrorists, removing the danger that the Metal Gear posed. The U.S. Government then covered up the whole incident and REX was abandoned on the island.

The Manhattan Incident

See also: Tanker Incident and the Big Shell Incident

A man-portable rail gun was the main weapon of Fortune, the leader of Dead Cell, during the Big Shell Incident. It had an extremely long reload cycle making it most suitable as a sniper rifle. It also had a massive recoil effect, as well as having a huge amount of bugs and errors (mostly related to the rail plasma and the inner rail electromagnetic release) due to it being a prototype model, making it far too dangerous for normal use in combat to the enemy and to the user, as well as being cited via evaluations to be unacceptable to be used as a field weapon for those reasons. Fortune was able to use it in normal combat without the gun accidentally discharging due to "being lucky."[6] Fortune used the rail gun until her death at Revolver Ocelot's hands.

Guns of the Patriots Incident

See also: Liquid Sun, Solid Sun, Third Sun, Twin Suns, Old Sun, and Naked Sin/Naked Son

Solid Snake, equipped with a man-portable rail gun, in 2014.

In 2014, Liquid Ocelot sent Vamp and Naomi Hunter to Shadow Moses to retrieve the rail gun attached to REX. The facility's stockpile of stealth "naked nukes" was the only way to directly attack JD's satellite without the Patriots knowing about it.

Crying Wolf, of the Beauty and the Beast Unit, used a man-portable rail gun against Solid Snake on Shadow Moses. The technology was provided to Liquid Ocelot by Vamp, following Fortune's death, and placed in Wolf's hands.[7] However, Snake was able to defeat Wolf and he ended up procuring the weapon himself. While compact, the rail gun packed as much firepower as a tank turret. It had the most penetrative power of any weapon in Snake's arsenal and dealt extremely high damage to targets. Snake later used it to hold off an entire division of Suicide Gekko.

World Marshal Incidents

See also: Raid at World Marshal, Ambush in Africa, Abkhazian Coup, Investigation in Guadalajara, Raid in Denver, and Operation Tecumseh

During one of Raiden's missions for Maverick between 2014 and 2018, Raiden managed to retrieve several amounts of blueprint data, at least one of which related to the Blade Wolf, where he was shown to have a man-portable rail gun. Although the LQ-84i himself did not possess the weapon by the time he and Raiden fought in Abkhazia, his mass-produced models, the Fenrirs, possessed the weapon system.

Behind the scenes

While a rail gun in 1974 may seem far-fetched, rail guns are not as futuristic as is commonly thought. The first patent for a rail gun design was issued in 1918, and in late 1944, the Luftwaffe Flak Command were developing a 128mm rail gun design for antiaircraft use; Allied studies in 1947 concluded that the design was functional, but that each gun would require enough power to light half of Chicago. The first large-scale working rail gun was constructed in 1950 in Australia, and used to gather scientific data.

The explanation in Metal Gear Solid for the rail gun making nuclear warheads untraceable is largely inaccurate. This is because a rocket engine applies force to an ICBM over a prolonged period of time; for example, a Trident ICBM's boost stage, which accelerates the missile to roughly 20,000 feet per second, lasts roughly two minutes. If REX's rail gun is imagined to be around 50 feet long, it would have to accelerate the projectile to the same speed in the 0.005 seconds before the warhead left the weapon.

Imagining the warhead to weigh 862 kilos[8] (the size of a Mark 23 nuclear gun round for a 16" / 50 Calibre Mark 7 battleship gun), it would have 16,016 megajoules of kinetic energy at launch. Since no machine is 100% efficient and most are nothing like this, it would not be exaggerating to imagine the rail gun's wasted energy (in the form of recoil, heat and mechanical deformation of the rails) would be the same amount of energy again, meaning the heat energy emitted by REX on firing would be the equivalent of the detonation of about four tons of TNT. This and the superheated trail caused by the round's passage through the atmosphere would mean a Metal Gear firing its main weapon would be easily detectable by existing systems designed to spot ICBM launches.

The rail gun as it appeared in Metal Gear Solid 2 was not completely digitalized: Rather, a wooden prop was created for motion capture sessions, although its size in-game made it so that it would end up heavy. At one point, Fortune's motion capture actress complained about getting "covered in bruises" every time she used it.

Fortune's rail gun concept artwork with Metal Gear RAY concept artwork.

The rail gun, which can be used in Metal Gear Solid 4, possesses 3 levels of charge. A Lv.1 charge is comparable to the DSR-1's punch, while a Lv.2 charge is comparable to explosives. A Lv.3 charge is even more powerful, allowing an instant kill on a Gekko, with one shot to the head. Ammo in-game is scarce and should be used sparingly, though more can be bought from Drebin 893 if the player has earned enough Drebin Points. However, its long charge time puts it at a disadvantage against multiple close range targets, especially during Act 4 where some areas had more than one Gekko to deal with, and when the players hold off a group of Suicide Gekkos near the end.

In Metal Gear Solid: Peace Walker, the rail gun has no use in single-player mode, as it requires an external Dynamo, making it a CO-OPS exclusive weapon. It was unlocked by getting an S-rank against Custom Chrysalis.

Railgun dynamo, featured in Peace Walker.

"An electromagnetic accelerator cannon currently being researched throughout the developed world. It fires projectiles with a kinetic energy of over 10 megajoules, on par with those of a tank cannon.
Naturally, this makes the rail gun orders of magnitude more powerful than anything else, able to destroy almost any target in a single shot. On the other hand, it also consumes an enormous amount of electricity, making it essential to have a CO-OPS teammate nearby to charge the weapon between shots.
―Weapon description in Metal Gear Solid: Peace Walker
"A remote charging system for the rail gun, employing an experimental microwave power transmission mechanism under development in several countries.
This device is absolutely essential in order for the rail gun to unleash its full power. When using the rail gun in CO-OPS play, make sure somebody on the team has one.
―Weapon description in Metal Gear Solid: Peace Walker

Aside from the rail gun used during CO-OPS, Chrysalis' rail gun can be recovered if the player manages to avoid damaging it from fighting the Mark II and Custom versions of the AI weapon, and installed onto ZEKE as one of the optional parts. Despite being designated as an optional part, however, getting it is required for accessing the true final boss and getting the second ending.


Read more

The Science of Rail Guns, an article about the actual history of rail guns by Keith Veronese.

Notes and references

  1. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Railgun: An electromagnetic accelerator cannon currently being researched throughout the developed world. It fires projectiles with a kinetic energy of over 10 megajoules, on par with those of a tank cannon.
  2. ^ Metal Gear 2: Solid Snake - User's Manual, Konami Corporation (1990), p36.
  3. ^ Metal Gear Solid, Konami Computer Entertainment Japan (1998).
    Otacon: The [rail gun] technology was originally developed for the SDI system and later scrapped. We were successful in miniaturizing it in a joint venture between ArmsTech and Rivermore [sic] National Labs.
  4. ^ Metal Gear Solid, Konami Computer Entertainment Japan (1998).
    Kenneth Baker: You've got to stop them. If it goes public, my company and I are... finished. // Solid Snake: What? Doesn't Metal Gear use currently existing technology? // Baker: Metal Gear itself does, but...
  5. ^ Metal Gear Solid 2: Sons of Liberty, Konami Computer Entertainment Japan (2001).
    The deaths of Donald Anderson, the DARPA chief, and Kenneth Baker of ArmsTech ended the development of a new Metal Gear. The Metal Gear REX unit itself had been all but completed under Hal Emmerich's leadership,
    (Page 316) but my source at Lawrence Livermore indicated that the rail gun warhead delivery system had not been fully operational. Apparently, there had been some serious issues with the rail gun's targeting accuracy. This was no doubt the reason Baker had entrusted Snake with the exercise data, and Jim Houseman, the Secretary of Defense, had so aggressively pursued its whereabouts. The data is now lost, and the development
    (Page 317) program has been closed down. I dare to dream that the new nuclear delivery system will never see the light of day.
    ::--In the Darkness of Shadow Moses: The Unofficial Truth by Nastasha Romanenko
  6. ^ Metal Gear Solid 2: Sons of Liberty, Konami Computer Entertainment Japan (2001).
    Rosemary, in a Codec conversation, reveals this to Raiden.
  7. ^ Metal Gear Solid 4 Database ("Rail Gun"), Kojima Productions (2008). [1]
  8. ^ This assumes REX is firing the barely produced W23 nuclear warheads. Far more common, and much more likely to be in the caliber appropriate to REX, are the W48 (a 6" round, weighing 56kg,) and the W33, (an 8" round, weighing roughly 109kg.) As these are the only two nuclear artillery rounds produced in bulk, these are likely what would be available at the Shadow Moses decommissioning site. Even assuming the greater mass of the W33, 109kg at roughly 7km/s is only around 2,500 megajoules... or about as energetic as a lightning strike. This seems far more feasible to hide from counter-ICBM systems.