The Super Heavy Armored Railway Artillery 2250 (nicknamed "The Monsters") were a series of 60 Railway Siege Artillery meant for long range bombardment of defensive fortifications, cities, and other large strategic assets. Designed just before the outbreak of war and the first 10 built in the beginning of the war production was halted to focus on more defensive assets. Originally designed to have a max elevation of 70 degrees it had to be brough back to 45 as the dirt beneath the gun already had to be dug out to allow the breech room to not hit the dirt and having a higher elevation might put too much stress on the elevation gears. Thought to t be useless on the defense most guns were pulled back East of T'Chong to be put in storage and use the AA mounted on them to bolster the cities defenses, however Gun Number 6 was late to be pulled back do to one of the locomotives breaking down and was forced to wait until its repairs was complete. Hearing of the Landings at Ang Gun 6 was within range and provided great assistance to the local defense to prolong the Ko'Jan forces from gaining a beach head and allowed E'Fo'Nan troops time to dig in deeper, how ever the defense would later collapse sometime after the pull back of Gun 6 however it is thought that Gun 6's leaving was not at fault for the collapse of the defense. Mounting a massive 100cm Rifled Gun with a firing range of over 50km The Monsters could put heavy amounts of explosives and firepower on a target with relative accuracy using the most advanced meteorological equipment and mathematical computations at the time along with aid from a limited degree of traverse on the gun. Sitting on 4 bogies with 8 wheels per side and riding on 6 meter wide track the Monsters had new track laid specifically for them where ever they went to take the colossal mass of the system at 2,250 tonnes. Most notably employed at the Siege of Gud'Mit and the Invasion of Mo'Gu where they provided destruction of Ko'Jan roads, defenses, command posts, and cleared landing sites the Monsters were deemed vital assets by the Army to provide a large amounts of assets in their use and defense. The first major asset was the detachment of a whole engineering, Anti-Aircraft, and Infantry battalions to each gun along with a fighter wing and spotter plane in the air. The gun would act as housing for some of its crew along with the main Fire Control Center with the inside of the chassis holding much of the brain center for the gun.

For the scale the Schwerer Guztav is in the background and is that design by Lord_Dakr on YouTube

Stats
Name: Super-Heavy Armored Railway Artillery 2250
Range: 50km
Weapins: 1x 100cm Heavy Artillery Cannon 2x Quad 50mm Anti-Aircraft Guns, 18x 15mm Heavy Machine Guns
Total Built: 60
Service Use: 1947-1908BCE
Preserved: 3

Might try and find a way to get this into a firing angle too