Railgun Pulsed Power Program

Electric Gun Integrated Launch Package

Since 1987, UT-CEM has been developing aluminum metal armatures for launch of large caliber hypervelocity projectiles for various United States Department of Defense programs. Considerable emphasis has been placed on the armature design for tactical railgun systems with the goals of increased system efficiency, reduced system complexity, and minimum bore damage. UT-CEM armature development efforts are typified by systematic design evolution punctuated by revolutionary performance breakthroughs. UT-CEM integrated launch package developments have led to a better understanding of the interdependent nature of launch package and electromagnetic gun design and demonstrate that the design of each must be coupled in order to successfully maximize overall launch system effectiveness. The following program discussions serve to illustrate this point.

Task B
In the 9 MJ Laboratory Gun Program (Task B), a solid armature development effort was initiated although solid armature development was not a specific contract requirement. Initial armature designs evolved from multi-contact monolithic types fired from a 13 mm square bore gun (a), to the 7075 T651 aluminum, single contact, U-shaped configuration shown in b. This U-shaped armature was originally developed to accelerate launch packages in a base-push configuration (c). Ultimately, armature development under the Task B program demonstrated that a two-piece armature could successfully accelerate a long-rod projectile in a mid-drive configuration (d).

The Task B program was funded to provide a large-caliber electric gun launch facility for ARDEC’s advanced projectile development programs. During the course of Task B, 97 tests were conducted from the 90 mm bore gun and represent the largest database of high-energy, large-caliber solid armature tests in the world.

SLEKE
Advanced mid-body drive, integrated metal sabot/armatures have been developed for launch of tactically-configured armor penetrating subprojectiles within the Sabot Launched Electric gun Kinetic Energy (SLEKE) projectile program. Kaman Sciences Corporation and UT-CEM (under subcontract) developed and tested five generations of large caliber metal armature and sabot designs. Sub-scale armatures were also designed and tested to validate full-scale electromagnetic and structural finite element modeling methodologies, extend armature contact transition velocity and establish material performance limits

CCEMG
In the Cannon Caliber Electromagnetic Gun (CCEMG) program, United Defense FMC/BMY, UT-CEM (under subcontract) and Kaman Sciences Corporation performed a detailed analytical trade study of the performance domain for a number of discarding armature and barrel configurations. Each configuration was sized to launch a set of functional sub-projectile designs capable of defeating program target requirements at 1,500 and 1,300 m range. The resulting electromagnetic launcher system was to weigh less than 5,000 lb. Drawing heavily on our previous launcher and armature design experience, an optimization algorithm was developed which integrated the armor-penetrating sub-projectile (designed by Kaman Sciences) with a discarding armature/sabot (forming the integrated launch package) which was in turn coupled to the design of the electromagnetic launcher. Design study results showed that minimizing breech energy required by the launcher would minimize total system mass. A two-turn augmented, rectangular bore barrel, firing a 100 g subprojectile and mid-drive discarding armature at 1,850 m/s resulted in minimum system mass.

EMFTD
The Electromagnetic Focused Technology Demonstrator Program (EMFTD) was initiated to develop next-generation component technologies for future large caliber electromagnetic armament systems. Under subcontract to Systems Application International Corporation on this program, and Custom Analytical Engineering Services have continued to advance the state of the art in electric gun launch package development. Central to the goals of the program are a launch package muzzle kinetic energy of 20 MJ, launch velocity of 3 km/s, a launch package parasitic mass ratio less than 50%, and a 1,000 shot gun life. To achieve these goals, advanced carbon composite sabot materials, optimized lightweight solid armature geometries, and refractory gun bore materials are being employed. To validate full-scale designs, a highly successful sub-scale testing effort has been pursued wherein a 90% action to melt, 75 kpsi bore pressure aluminum armature has been demonstrated and has extended the armature transition velocity limit to record levels.

Sponsors
The Task B 9 MJ Repetitive Fire EM Launcher was sponsored by U.S. Army ARDEC. SLEKE was sponsored by U.S. Army ARDEC. The Cannon Caliber EM Gun program was sponsored by U.S. Army ARDEC and the U.S. Marine Corps. The Electromagnetic Focused Technology Demonstrator Program was sponsored by the U.S. Army ARDEC and the Army Research Laboratory Weapons Technology Division.

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Army Electric Gun Program

For further information please contact:
John Pappas
Program Manager
(512) 232-1644
j.pappas@mail.utexas.edu