The practice fields were buzzing with activity. Many frontiersmen, various workers, and some students all stand around the massive metal object that was pulled through campus and are even more curious about the strange cart following behind it. The heavy cart rumbles out to the field and the cannon is lined up about 100 meters away from one of the walls. Before the cannon is loaded I go and inspect the small wall.
It's 10x10 as requested, but has a nearly meter-deep foundation. It also has some stone triangles on the back of it in order to brace the wall from impact. Despite being made of individual bricks the wall appears to be one solid piece of stone, this is thanks to earth magic which can fuze stone in order to increase the fortification strength. The wall itself is nearly a foot thick, meaning it is quite durable. Satisfied with the wall I return to the cannon and start the leading process.
The first test will be done with a solid shot with three powder charges. Each charge is 8 inches in diameter and is as long as the projectile. After the last charge is placed I place the 8-inch diameter plate made of flash stone before with the help of one of the workers for the cannon we slam the breech closed and lock it into place. In order to have opened the breech the firing ballista was half-cocked, but with the breech closed it is cranked all the way back. I grab the string I tied to the trigger and take multiple paces back. I motion for everyone to cover their ears and to stand back. Just as the central clock strikes 10 AM I pull the string.
A half-second pause...
Then a deafening boom that I feel through my bones as wind blows past everyone present. The brilliant flash of smoke and fire throws dirt up into the air in a cone in front of the gun as a trail of dust arcs toward the target. The wall is blown apart as the lead projectile transfers the intense energies into the stone and many meters behind the wall there is a towering plume of dirt caused by the impact of the shell. It takes a few moments for the bits of the wall to finish raining down. Then in the silence after the bang, a loud cheer rings out and everyone begins cheering at the achievement. The cannon didn't explode and it worked about as perfectly as it could've. After the cheer ends I go to inspect the rifling of the barrel. After one shot there appears to be no damage to the rifling, but one shot theoretically shouldn't.
The breech is opened, revealing smoldering remains of the powder casing. This reminds me to have some sort of cleaning swab made for the cannons. For now, we find a long pole, wrap the end with a wet rag, and swab the interior of the cannon, clearing out all of the leftover material. After final checks over the mechanisms, making sure everything worked I approach the devastated wall.
To say the wall was devastated is an understatement. I do note the cannon hit low at 100 meters and plan to elevate the barrel by a degree or two for more center-mass tests. The foundation remained rather untouched but the shell hit ten inches above the foundation line. I can tell this by the half-circle smashed through the remaining bits of the wall. From what I can tell, the soft lead projectile looked to have deformed upon impact, but the high velocity transferred incredible energy resulting in a sort of explosion. I have to remind myself that despite the similar size to cinderblocks the bricks used in this test wall are made of solid limestone, I think.
The wall exploded inward, smashing through the reinforcement triangles, and what was above the impact site appeared to get thrown into the air. I find where the projectile ended up and find not just one hole in the ground. The projectile seemed to have blown itself apart after hitting the wall becoming a wall of shrapnel mixed with the stone shrapnel, but there was still a mostly intact blob of deformed lead at the bottom of a small crater. I dig the object out of the ground proud of how messed up the lead is.
For safety precautions, I pay a few coins to some of the earth mages in the crowd to build earth backstops behind all of the testing walls. With the cannon adjusted and new powder loads loaded, only four of the walls remain standing at the end of the day of testing as I plan to test the smaller secondary guns on them.
Back in the drawing room with the cannon undergoing cleaning inside the workshop, I begin doing math trying to figure out the specifications of the cannon, mostly so I can make gunsights later.
For powder loads, I decided on a variable load type of weapon. Three charges for hard targets, two is standard and general purpose, and one for close range and softer targets.
If my math is correct based on some longer range tests done while firing the triple load has a velocity of 500 m/s, the double load is about 350 m/s and the single is about 275 m/s. Overall these speeds are a little lower than modern cannons but are incredibly powerful for a time and place without any form of powder weapons.
It takes me a moment to come to terms with the destructive capability of this gun. Because of my civilian background, I never saw what a big bore cannon can do to a wall. I've only seen footage from distant wars and just assumed since my 8-inch gun is rudimentary compared to modern firearms it would maybe be as strong as something like the M3 75mm gun on a Sherman or something. Simply punching a hole through a wall and that's it. The hot load devastated a wall, the standard load did about the same but less devastating, and the single load shattered the wall with heavy shrapnel blowing through. I never could have predicted. I still am left unsatisfied so I send orders, exchange money, and prepare an airship for a real test.
The next day all involved spend hours loading the massive cannon onto a small airship. This airship was chosen due to the large doors on the side of the hull, the width of the ship being wide enough for everyone, and the cannon to be aimed out of the doors.
I purchased an old fort from some minor noble who had been using the antique structure as a storage shed. Only the top towers have foot-thick walls, the base and mid-level walls range from six to three feet thick. I want to fire this gun into a realistic fort at realistic ranges in the air. I even make sure the day chosen is extra windy to see just how weather and rage affect the ballistics.
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We bring with us, an actual bore cleaning swab, some earmuffs to protect hearing, and some of the anti-fortification shells for testing. Henna is meeting us there where she brought some slaughtered hogs to hang inside various targeted locations of the old fort to see the effects the shells have on bodies hiding inside.
It takes a few days for everything to get set up for testing. The corpses take a while to acquire and place within rooms, plus getting the cannon ranged in, and figuring out the best location for the ship to hold for the testing. With the wind howling and the day nice, testing began.
The first test is one of the anti-fortification shells which up to this point had been untested. A standard charge is loaded and the shell is aimed at one of the rounded towers. According to sources the walls are about a foot thick in this area, a thinner wall for sure, but a good starting point. The ship is sitting about 1 kilometer away and we are aiming with a prototype gunsight I put on top of the cannon. It's a simple notched piece of metal with ranges engraved on it, it lines up with a small bead placed on the end of the cannon barrel. In theory, it should work, but the goal right now is to just hit the target, not to be overly accurate.
With the entire fort evacuated and all ground personnel hiding in nearby trenches everyone onboard the ship puts on hearing protection and opens their mouths because I had seen something about that when firing a big gun in an enclosed space watching TV before. I pull the string and the entire airship shudders as the chained-down cannon tries to fly backward from recoil. There are a few seconds of pause, then the tower violently explodes. There was enough time for me to watch the front wall we aimed for collapse inward and in a split second the back wall exploded outward and the flash stone exploded violently due to being trapped in a sealed container. With the structural stability of the tower having been compromised the remaining sides explode outward from the bomb going off. I don't even have to guess what happened to the bodies inside.
Happy with the first test we swab, reload, and then aim at a middle area of the fort. It's some random storeroom on the second floor, but three pigs were hung up inside. The wall is supposed to be around four feet thick and made of solid limestone. The ship moves slightly forward and the loaded shell is one of the soft lead ones. I want to see what the cheap shells can do to a harder target.
A shot, and then a result. There is a massive plume of dust as the masonry is devastated by the shot. While the wall does still stand, there is now a large hole punched through it, and looking through a telescope I can see the inside which also has empty crates inside of it along with the corpses looks pretty rough. I wave a flag to the ground crew and they rush inside to look at the damage.
After a moment from the hole in the wall, they flash a yellow flag followed by a red one. As part of the setup, we agreed upon a code system. Green through black flags. Green means no damage, and black means obliterated. The first flag is for the contents of a room, like the pigs or the furniture or supplies. The second flag is for internal structural damage, meaning the rear walls or floors of the building. It's a highly subjective measurement based on what the ground crew considers each to be, but that's good enough when it comes to after-effects.
From what I gather, the solid lead caused a heavy amount of shrapnel to form from the masonry which then blew inward and destroyed lots of things inside, but anywhere not directly behind the blown-through wall was left more or less unscathed. As for internal structure, I assume the shell either destroyed the internal wall which is about six inches thick, or fell through the floor which is of unknown thickness.
I flag the ground crew to evacuate as the anti-fortification shell is loaded and the ship backs up so the cannon is aiming at a completely unmarked section of the same wall. As the cannon is reloaded the ground crew enters their trench and waves the flag signaling their safety. With that done another round is fired.
I understood already that the after-effect will be lessened due to the free ventilation we gave to the room. The pressure wave from the explosion can be lessened due to the extra space where the expanding gasses can escape. The steel shell punches a small hole in the wall, knocking in a two-foot wide hole, shattering the small section of masonry, and then a cloud of dust rapidly expands out the new hole along with the one made only recently. The blast rings out across the plains as smoke follows the brown cloud of dust. I wait a moment for the room to cool off before motioning for the ground crew.
Through the haze of smoke, I see two black flags flash, and one of the crew carries a ragged and destroyed pig to the bigger hole, showing the aftermath. The corpse is not only shredded but has clear charring all over it and the skin is brown and clearly quite crispy. I motion for them to leave out of concern for their health as the smoke doesn't let up. As for the internal structure damage I mentally reference the tower of before, how the blast was strong enough to tear apart a foot-thick wall, so a thinner one would be easy.
The final wall test is done on the six-foot-thick base walls. The lead shot was unable to make a hole at two charges standard load but left the wall heavily cracked and broken, a second testing shot finished the job, finally shattering the last of the stone. The Anti-fortification round also had difficulty at standard load. While it did make it through, it barely did so and the first shell didn't detonate as the trigger didn't receive the second impact required. A hot load removed this issue during tests. A hot load for the lead shot resulted in once again no penetration, but the follow-up standard shot created more damage than the two standard loads.
Satisfied with the anti-fortress ability of the cannon there is one last test.
I purchased an old warship that was going to be sold as a merchant vessel. It was surprisingly cheap, but it was overall smaller than average. Regardless it is still made of the same wood and with the same design philosophy as most national air navies. This makes it a good testing target. It is moored one hundred meters above the top spire of the fort and the airship the cannon is loaded on raises itself to the same level and we aim.
The first is a standard load with a solid lead shot. The result is adequate. The wood is splintered and multiple layers of the ship are penetrated. One shot is not enough to sink it, but the damage is extreme and by my estimation five or six more shots would cause the ship's hull to completely break apart. Then the anti-ship shell is loaded.
We aim for an undamaged section of the ship and fire. The shell makes contact and detonates immediately as expected, but the steel casing is slightly thick enough to hold up for a split second resulting in the rapidly expanding, sticky, fireball being forced inside of the ship. A wall of flame spits out of the various portholes on the vessel and out of the hole already smashed through the ship's hull. The resulting blast throws the sticky payload all over the wooden interior of the ship and quickly, the ship begins to burn and soon it crashes into the old fort in a burning heap.
I am satisfied with the performance of the cannon... no not satisfied...but absolutely ecstatic.
Returning back home I tell Markus and the foreman my findings and now understanding the capabilities of my weapons, Markus continues creating the ship.
By estimation, the ship will take three months to be airworthy and four to be completely ready for combat. All I have to do is keep the materials flowing and continue working on the gunsights for the future airship, which at the moment remains unnamed. I almost feel bad for the Lusthardia fucks... almost...