Lævateinn

The Lævateinn (レーヴァテイン) is a Legitimacy Kingdom armored combat train deployed in the Northern European Restricted Zone.

Etymology
The is a weapon from.

Design
The Lævateinn is a giant armored train. It has an enormous size, compared multiple times to Ayers Rock. Overall, it's bigger than an Object. It has six cars with a large circular mass crossing between 3 of the cars, the high-speed gun car carrying the train's main weapon.

Principles
The Lævateinn is an armored combat train created by the Legitimacy Kingdom. Due to the amount of armor and firepower, the Lævateinn can only use preset rails. It’s just too heavy for bridges and too wide for normal tunnels, so it has to travel along the coast. However, due to its large amounts of armor, no amount of air-to-surface missiles can stop it. Even after heavy bombardment and air strikes the Lævateinn's armor had only suffered small damage.

Its main weapon is a huge ground-to-air flak cannon that uses ridiculous amounts of explosives on its shells, to the point it can cause mushroom clouds. While impressive, the main point of the shells is to detonate them high up in the sky, using the explosive blast and wall of turbulence to target relatively high-flying fighters and unstable attack helicopters. It does not matter than the shell is unguided, the Lævateinn just has to shoot near the enemy fighters to create a wide-range vortex of destruction. The skill of the enemy pilots is made irrelevant as a kilometers-wide surface drops down on the aircrafts like a flyswatter. Because of this, the cannon is nicknamed Drop Ceiling (吊り天井) by the Capitalist Corporations. The high-speed gun car carrying the main cannon on the center of the train moves along a closed loop of linear rails and the appropriate amount of both centrifugal force and liquid gunpowder is used to shoot the shell. The front and back cars have connectors to the circular rail that act as a damper so that it can slide properly around the curves without doing any damage.

Additionally, the Lævateinn is covered in battleship-style heavy cannons using old-fashioned gunpowder charges for surface bombardment, and so many anti-aircraft guns on the top that it looks like a honeycomb. The AA guns can adjust the internal rifling to the values needed to apply the appropriate spin for curving the shell however one wanted. While the individual shots are not all that accurate, it provides a storm-like barrage against any aircraft that managed to escape the main gun.

Much like giant aircraft carriers of old, the Lævateinn needs a huge support crew of 3000 to 5000 people to keep itself running (only about 800 directly involved in running it), and facilities to keep the crew fed and entertained, so a single weapon ends up turning into a small city.

Specifications

 * Class: Self-propelled Front Capture Gun
 * Length: 520m
 * Height: 80m (Including ground-to-air cannon circumference)
 * Width: 165m (Including ground-to-air cannon circumference)
 * Weight: 120,000t (Full weapons load)
 * Propulsion Engine: Clipper Shipbuilding Battleship Standard Diesel engine x 1
 * Top Speed: 220km/h
 * Armament: Ground-to-air Infinite Circumference Flak × 1, ground-to-ground 50cm cannon × 12, etc.
 * Crew/Passengers: Max. 830
 * Main Color: Black

Background
Around two weeks before the incident involving Mariydi Whitewitch, the rails which the train was using were destroyed by Capitalist Corporations combat engineers in a suicide sabotage mission. Despite being rendered stationary by the derailing, the Laevanteinn continued to push back the Capitalist Corporations war front for two weeks.

Girl's Fight at an Altitude of 10,000m
When Mariydi Whitewitch and Nancy Jolly-Roger were being pursued after the former was accused of treason and had a bounty placed on her head by conspirators, Mariydi took her bike onto a highway and lured her pursuers into the Laevanteinn's range to have the enemy factions fight one another. The Laevanteinn took out the enemy forces but didn't fire on Mariydi as it couldn't target her vehicle. As her fighter's wreckage was within the Laevanteinn's firing range, preventing her from accessing the flight recorder, Mariydi went back to the ruins of Asgard where the Laevanteinn was, together with Nancy, and engineered the deaths of the personnel outside the train via oxygen depletion and carbon dioxide poisoning. With the train having being sealed up to protect the crew inside, Mariydi blocked the exhaust vents so that the crew inside would meet a similar fate. When the two confirmed that the train was silenced and retrieved the flight recorder, surviving Laevanteinn personnel were infected with rabies-type synthetic molecular motors released by the conspirators and made to attack them.