Wall-Mounted Artillery

Wall-mounted artillery served as humanity's main anti-Titan weapon in the era before vertical maneuvering equipment existed. Its fundamental problem is biology: decapitating a Titan settles nothing, since roughly half of them regenerate the lost head, and only destroying the nape guarantees a kill. Slow reloading and aiming make cannons useless on the offensive, so they survive as static defenses, concentrated along the tops of the Walls and around the gates where a breach is most likely. The Garrison, which patrols those positions, fields them more than anyone else.

Beyond Paradis the picture looks very different. The world's modern militaries deploy far more advanced guns firing proper shells instead of round shot, and their pieces are wheeled or mounted on battleships and armored trains rather than bolted in place. Marleyan heavy mortars and the Anti-Titan artillery of the Mid-East Allied Forces represent the high end of this technology.

Paradis cannons load from the breech and fire when a string yanks the firing pin; a crew needs about twenty seconds per shot. Their accuracy is dreadful, most likely because the barrels lack rifling. Two munitions exist. High-explosive shells aim to obliterate the nape in the blast, but the guns' poor precision makes them nearly worthless at range. Grapeshot scatters wide and exists to shred limbs across a broad area, slowing a Titan advance rather than ending it.

Foreign ammunition is in another class entirely. The Mid-East Alliance's 100mm armor-piercing shells punch through any nape, including those of the Nine Titans, a technology they alone possess through their Anti-Titan cannons. Howitzer shells handle long-range barrages, though even massed volleys of them bounced off the Armored Titan when an enemy of Marley tried between the years 833 and 845.

The Paradis design also evolved. Before Wall Maria fell, each cannon could fire from only a single fixed point, and after the breach the Garrison had to drag guns down to ground level to meet the Titans. Rail lines were later laid around the entire circumference of the Wall, letting crews cluster their pieces and mass fire on one spot. A cannon must be locked down before firing so recoil does not throw it from the tracks, and the mounts allow a straight-downward shot, raining fire on Titans at the Wall's base with no risk of retaliation.

The Garrison owns this weapon's history. After Wall Maria fell, ground-deployed cannons proved almost pointless, their low-range fire angled at targets too tall to hit effectively, and nothing they had could so much as slow the Armored Titan at Shiganshina's inner gate. During the Trost crisis, Eren Yeager and his fellow trainees were on cannon-cleaning duty when the Colossus Titan appeared and deliberately wrecked the Wall-top guns and their rails to block reinforcement. One surviving cannon was later turned on Eren, Mikasa, and Armin, its shot stopped only by Eren's half-formed Titan body, and once the Trost gate was sealed, Wall guns pounded the Titans massed below with high explosives.

The weapon has seen stranger uses. Trapped at Utgard Castle, Reiner, Bertolt, Ymir, Connie, and Historia stopped a Titan inside the tower by ramming it with a derelict cannon. In Orvud District, the Garrison threw concentrated volleys at Rod Reiss's colossal Titan form, tearing up his back but failing to halt his advance or reach his nape.