this is what we need in the MA,
"SheVas were four hundred feet long and three hundred wide, with huge tracks surmounted by a "turret" that looked like a metal factory building. At the rear, concealed in the turret, was a heavily armored magazine for its eight main gun rounds, each of which looked like a cross between a rifle cartridge and an ICBM. The cantilevered gun, massive against any other backdrop, stuck out of the turret like a giant telescope and was so small in comparison it looked like an accidental add-on.
The gun consisted of three main portions, the gun itself and its supporting structures, the monstrous "weather shield" turret that created the gun room and the drive system.
The gun was a two hundred foot long, multi-chambered "Bull" gun. The basic propellant was an electro-plasma system that used an electrical charge to excite material and provide propulsion far beyond that available with any normal chemical propellant. However, due to power drop-off over distance, the barrel had secondary firing chambers down its side that added their own propulsion to the gigantic projectile. The combination permitted penetrator rounds, discarding sabot rounds with an outer disposable-plastic "sabot" and an inner uranium penetrator, to reach a velocity of nearly twenty five hundred meters per second, an unheard of speed prior to the SheVa gun.
It was mounted on a pivoting turret and elevation system that permitted it to fire from just below zero degrees to just beyond "straight up." It was, after all, designed as an anti-"aircraft" gun.
Instead of the normal "bag and round" system of most artillery, where the actual "bullet" was first loaded and then bags of powder rammed in behind, the gun used enormous cartridges that looked like nothing so much as a cross between a rifle cartridge and an ICBM; eight of the rounds were stored in a heavily reinforced magazine at the rear of the turret. Damage to the turret was to be avoided: depending upon whether the system was loaded for "penetrator" or "area of effect" there would be from eighty kilotons to eight hundred kilotons of explosive riding around in a SheVa. For that reason, among others, regular units tried to give them a wide berth.
To protect all of this machinery, some of which was not particularly weather proof, the gun was encased in a gigantic "turret", actually a simple weather shield, that was a major engineering feat in itself. The shield was a hundred foot wide cube which mounted to the turret ring at the base of the gun so that it rotated at the same time as the weapon. The exterior of the shield was six inch steel plate, not for any armoring reasons but simply because any lesser material buckled whenever the gun fired. The interior, on the other hand, was mostly empty, a vast space of soaring girders and curved braces that held the shield in place.
At the center top of the exterior of the shield was a crane, much better supported than the rest of the structure, that served to move around the humongous equipment necessary for even the simplest repairs to the gun.
To drive all of this structure required more than a little power. That was supplied by four Johannes/Cummings pebble-bed reactors. The core of the reactors were the "pebbles" themselves, tiny "onions" with layers of graphite and silicon wrapped around a fleck of uranium at the core. Due to the layering the uranium itself could never reach "melting temperature" and, therefore, the reactors were immune to run-away reactions. Furthermore the helium coolant system prevented any radiation leakage; helium was unable to transmit radiation and thus even in a full coolant loss situation the reactor wasn't going to do anything but sit there.
Admittedly there were...issues with the reactors. Despite careful use of Galactic heat regeneration techniques, the drive room was hot as the hinges of hell. And if the reactor took a direct hit, as had happened from time to time, the tiny "pebbles" became one heck of a radioactive nuisance. But the power that the reactors provided more than made up for those little shortcomings. And reactor breaches were what clean-up crews lived for.
The drive system for the tank was just as revolutionary, using induction motors on all the drive wheels to provide direct power. Thus the SheVa could lose one or more drive wheels and still continue moving"
Above copy righted by John Ringo 2003
Gunns
