Thunder Spear (Anime)

The Thunder Spear (雷槍) is a technology specifically developed to fight against the Armored Titan. Hange Zoë describes it as being "like a strike of lightning," hence its name.

Mechanics
The Thunder Spears are based off of technology that had been preserved in secret by the Interior Police, despite their orders to wipe out any sign of technological innovation. This technology was adapted to design a new special weapon for use against the Armored Titan. It works in a similar fashion as the Anti-Personnel omni-directional mobility gear's guns and hooks, but with a strong spear loaded with explosives designed to shatter armor.

These weapons work as a two-stage rocket: an initial charge launches the projectile by pressing a special trigger in the handle of the device. The projectile, connected by a rope to the main engine, is launched with enough power to penetrate hardened Titan skin. However, when that rope is cut, the second charge is activated. This causes a tremendous explosion which makes the projectile penetrate even more into the target.

Usage and limitations
The Thunder Spears are a weapon which enables a human team to efficiently launch a surprise attack against the Armored Titan. But this weapon plays the role of a double-edged sword, as it is a danger to its user as well as the Titan. So much so, that it is only useful in a specific type of situation where after use, immediate retreat to close structures via ODM gear is possible. Without a proper surrounding, the user is easily liable to get caught in the explosion. While it is also capable of damaging other types of Titans, it was designed solely to kill Reiner, the Armored Titan.

Training
In preparation for defeating the Armored Titan, Squad Levi did not have much time to train, but Hange carefully placed her troops so that they would be in an optimal position to attack. It is a maneuver that requires three successive attacks: the first to blind the target, the second to break the protective shell, and the third one to kill.

Return to Shiganshina arc
Hange Zoë has the Corps of Engineers develop the Thunder Spears, using technology uncovered following the coup d'état. Designed as a weapon to combat the Armored Titan, Hange displays the performance of the spear to Scout Regiment soldiers.

In the battle in Shiganshina District, the members of Fourth Squad and the Special Operations Squad surround the Armored Titan in its battle, barraging it with explosives and blowing through its armor to detonate its nape.