Written by Michael Garrity
New Omaha Vehicular Association
garritym@hotmail.com

Web Posted August 03, 1998
Updated August 01, 2000

Far from being a science-fiction "weapon of tomorrow," the concept of a weapon using an electromagnetic impulse for propulsion originated as far back as the mid-to-late 1930s. Basically, a Gauss weapon consists of a system of powerful electromagnets which throws a projectile by accelerating between a number of metal rails. There are two types of Gauss weapons: railguns and massdrivers. Railguns fire high-density metal projectiles at extremely high velocity, while massdrivers fire a conventional explosive shell at a velocity which is about the same as a shell fired from a conventional artillery piece. The statistics for Gauss weapons and their ammunition are listed below.
 

Electromagnetic Railguns

These weapons are divided into two types:

1. Gauss Needler, a weapon that fires a small-caliber (1mm to 2.5mm) projectile at a very high rate of fire.
2. Gauss Cannon, a weapon that can fire a larger projectile (5mm+) than Gauss needlers. Their rate of fire is much lower than Gauss needlers.

All railguns have 20 shots (except for the 100mm and 150mm railguns; these two weapons have 10 shots each) and a to-hit value of 6. Light needlers use 0.10 power unit per shot. Medium needlers use 0.15 power unit per shot. Heavy needlers use 0.25 power unit per shot. Gauss needlers are area-effect weapons, while Gauss cannons are not.
 

Gauss Needlers

Light Gauss Needler -- $2,500, 100 lbs., 1 space, 2 DP, 2d6+2 damage, 0.10 PU/shot, CPS $25, WPS 2 lbs., Loaded cost $3,000, Loaded weight 140 lbs. Area effect.

Medium Gauss Needler -- $5,000, 200 lbs., 2  spaces, 3 DP, 3d6+3 damage, 0.15 PU/shot, CPS $50, WPS 3 lbs., Loaded cost $6,000, Loaded weight 260 lbs. Area effect.

Heavy Gauss Needler -- $10,000, 300 lbs., 3 spaces, 4 DP, 4d6+4 damage, 0.25 PU/shot, CPS $100, WPS 3.5 lbs., Loaded cost  $10,000, Loaded weight 370 lbs. Area effect.
 

Gauss Cannon

5mm Gauss Cannon -- $15,000, 350 lbs., 3 spaces, 3 DP, 0.5 PU/shot, 5d6+5 damage, CPS $150, WPS 3.5 lbs., Loaded cost $18,000, Loaded weight 420 lbs.

7.5mm Gauss Cannon -- $40,000, 500 lbs., 4 spaces,  4 DP, 1 PU/shot, 8d6+8 damage, CPS $200, WPS 5 lbs., Loaded cost $44,000, Loaded weight 600 lbs.

10mm Gauss Cannon -- $65,000, 700 lbs., 6 spaces, 6 DP, 2 PUs/shot, 10d6+10 damage, CPS $300, WPS 7.5 lbs., Loaded cost $71,000, Loaded weight 850 lbs.

15mm Gauss Cannon -- $200,000, 1,500 lbs., 10 spaces, 10 DP, 4 DPs/shot, 15d6+15 damage, CPS $400, WPS 9 lbs., Loaded cost $208,000, Loaded weight 1,680 lbs.

25mm Gauss Cannon -- $350,000, 3,000 lbs., 13 spaces, 13 DP, 10 PUs/shot, 25d6+25 damage, CPS $650, WPS 10 lbs., Loaded cost $363,000,  Loaded weight 3,200 lbs.

35mm Gauss Cannon -- $400,000 5,000 lbs., 15 spaces, 15 DP, 20 PUs/shot, 35d6+35 damage, CPS $800, WPS 12.5 lbs., Loaded cost $416,000, Loaded weight 5,250 lbs.

50mm Gauss Cannon -- $650,000, 7,500 lbs., 20 spaces, 20 DP, 40 PUs/shot, 50d6+50 damage, CPS $1,000, WPS 15 lbs., Loaded cost $670,000, Loaded weight 7,800 lbs.

75mm Gauss Cannon -- $900,000, 10,000 lbs., 25 spaces, 25 DP, 100 PUs/shot, 75d6+75 damage, CPS $2,000, WPS 20 lbs., Loaded cost $940,000, Loaded weight 10,400 lbs.

100mm Gauss Cannon -- $1,500,000, 20,000 lbs., 30 spaces, 30 DP, 200 PUs/shot, 100d6+100 damage, CPS $3,000, WPS 30 lbs., Loaded cost $1,530,000, Loaded weight 20,300 lbs.

150mm Gauss Cannon -- $3,000,000, 40,000 lbs., 60 spaces,  60 DP, 400 PUs/shot, 150d6+150 damage, CPS $6,000, WPS 40 lbs., Loaded cost $3,060,000, Loaded weight 40,400 lbs.
 

Railgun Ammunition

The standard ammunition for railguns of all types is a finned dart or spike made from tempered durasteel. This gives them the damage figures listed on the tables above. Depleted uranium ammunition is available for use by military forces. Depleted uranium ammunition for railguns causes the damage listed above, however, the DP of a target (armor, structural components, etc) is divided by three. This armor-penetrating ability is a function of the railgun's high muzzle velocity and the extreme hardness of depleted uranium itself.
 

Massdrivers

Massdrivers are low-velocity electromagnetic accelerators designed to fling a variety of shells. The chief advantage of a massdriver over a conventional artillery piece is that its shells are smaller and lighter than regular artillery shells.

40mm Electromagnetic Grenade Launcher (EMGL) -- $2,000, 200 lbs., 1 space, 2 DP, crew 1, 40 shots, 0.5 PU/shot, RoF 3, CPS $20, WPS 2 lbs.

50mm Massdriver -- $5,000, 320 lbs., 2 spaces, 3 DP, crew 2, 20 shots, 1 PU/shot, RoF 5, CPS $140, WPS 5 lbs.

75mm  Massdriver --  $13,000, 640 lbs., 8 spaces, 6 DP, crew 3, 20 shots, 15 PUs/shot, RoF 1, CPS $100, WPS 10 lbs.

105mm Massdriver -- $70,000, 1,200 lbs., 10 spaces, 12 DP,  crew 5, 10 shots, 25 PUs/shot, RoF 1, CPS $250, WPS 35 lbs.

120mm Massdriver -- $200,000, 1,600 lbs., 12 spaces, 18 DP, crew 6, 10 shots, 40 PUs/shot, RoF 1/2, CPS $500, WPS 50 lbs.

150mm Massdriver -- $400,000, 2,400 lbs., 15 spaces, 20 DP, crew 6, 5 shots, 60 PUs/shot, RoF 1/3, CPS $750, WPS 75 lbs.

175mm Massdriver -- $1,000,000, 4,800 lbs., 25 spaces, 25 DP, crew 10, 3 shots, 75 PUs/shot, RoF 1/4, CPS $1,000, WPS 100 lbs.

200mm Massdriver -- $1,500,000, 8,800 lbs., 40 spaces, 30 DP, crew 15, 2 shots, 100 PUs/shot, RoF, 1/6 CPS $2,500, WPS 125 lbs.

All massdrivers have a to-hit of 8, except for the 40mm EMGL, which has a to-hit of 7.
 

Massdriver Ammunition

Massdrivers of all types (except the 40mm EMGL*) can fire the full range of available artillery ammunition. The cost and weight modifiers are based on the CPS and WPS listed on the table above. Massdriver shells of all types (including the 40mm EMGL) are assumed to resemble  their conventional counterparts, except that they have no powder charge and are cased within a thin, steel sabot (which falls away from the shell after firing).

*  The only types of shells a 40mm EMGL may fire are HE, HESH, HEAT, HEDP and any of the laser-guided, teleguided or seeking projectiles.
 

Massdriver Accessories

Massdrivers of all bore sizes (except the 40mm EMGL) may use long barrels and autoloaders at the usual cost and weight.
 

Electromagnetic Mortars

Massdrivers (except for the 40mm EMGL) may be purchased as mortars. The weight of these "electromag" mortars is 75 percent of a massdriver of the same caliber. The cost is halved. The spaces are 75 percent normal (round down to the nearest whole space). CPS and WPS of the ammunition is unaffected.
 

Operational Characteristics of Gauss Weapons

Although flashless, Gauss weapons produce a unique electromagnetic signature when fired. This signature will be automatically located by any magnetic-anomaly detector. All Gauss weapons  give off  a low humming sound when operational. This noise is generated by the weapon's capacitors. Operational Gauss weapons (before being fired) can be located by a magnetic-anomaly detector at half-range.

The hypersonic velocity of railgun projectiles causes them to emit peculiar noises on being fired. A Gauss needler shot resembles a rapid series of sharp cracks, like the noise from a whip being cracked. A Gauss cannon shot is an actual sonic boom. Firing the largest railguns produces a noise which is audible for great distances, like the noise given off from a bolt of lightning. Pedestrians close enough to a railgun when it fires (GM's discretion) must make an automatic roll on the concussion-grenade effects table (with a +2 on the roll). The range of a massdriver is 25 percent greater than a conventional artillery piece or mortar of the same caliber. The noise of a massdriver shot is no louder than a shot from an artillery piece of the same caliber.