Chapter 567: Explosive Shells
Translator: TransN Editor: TransN
A suburb beyond the west city wall, Neverwinter.
A great roar attracted the civilians to ascend the city wall to watch from up high. The First Army had sealed the entrances to the Misty Forest in case anyone broke into the experiment ground.
Although the location was not close to the city wall, one could clearly see what was happening with a telescope from there. "It seems we have to look for a remote place as a special base for testing firearms." Roland thought to himself.
"Your Majesty, the second volley is ready!" An artillery soldier reported.
"Everybody goes into the bunker." Roland waved his hand. "Start the countdown after confirming no one is on the ground."
It was the test fire of the 152 mm Howitzer. While researching on the Sigil of Magic Stones, Roland included the advancement of firearms. Now with Timothy being killed and the Northern Region having announced submission, the situation in the Kingdom of Graycastle was fairly good. Now Roland had time to put his mind on further promoting the shells.
But he had to admit that the technical difficulties of developing a howitzer with an impact detonator were much greater than those of developing solid shells. Anna would make four howitzer shells for test fire every day. Yet three consecutive days later, none had successfully exploded. What's worse, on the second day, one shell exploded right after it got out of the chamber, which damaged the new artillery barrel too much for test firing. Fortunately, Roland took precautions by digging several trenches around the experiment ground, which successfully prevented casualties. The eardrums of a few soldiers who stayed close to the artillery were damaged by the roar, but Nana healed them in time.
"Is this thing really like what you said, exploding the moment it touches the enemy?" Agatha could not help but stick her head out to watch. "I've asked Anna. It's nothing but a few pieces of sheet metal put together. It's not alive, so how can it know whether it touches is an enemy?"
Agatha must be the most enthusiastic witch toward weapon test in the union. Upon hearing the test, she put aside her production work in the chemical plant and personally came to observe the research development of the new shell.
"It doesn't explode when it touches the enemy, but when it falls into the enemy's position." Roland corrected her. "It's a basic requirement the Howitzer has to meet—if there isn't a safety to make sure of it, the shell could fire accidentally at any time. That would be too dangerous."
The trigger safety was the most basic technology for the new shell, at the same time the focal point of the test.
To prevent explosions triggered by collision or accidental drop, Roland made great efforts to set three safety systems.
The first one was to separate, store, and transport the fuses and shells, and install them when needed. The fuse looked like a cone with a handle and was the size of a fist. With the threads on its bottom, it could be conveniently and easily screwed into the notch on top of the shell. The shell was filled with double base chemical gunpowder, a kind of material that was hard to ignite without a detonator, which essentially ensured the logistics work.
The second one was the inertia safety in the fuse.
The safety device resembled a gate lock. Unarmed, it could not move due to being held in place by a stiff spring; when the shell was fired, the tremendous inertia kicked back the lock cylinder, overcoming the resistance of the spring, pulling open the latch, and removing the safety.
The theory was easy, yet hard to put into practice. Roland and the witches spent most of the first two days on it. If the spring was too hard, the lock cylinder could not get enough recoil distance; if it was too soft, it could not guarantee safety. Anna had to gradually adjust it based on the test results. After eight rounds of test firing, they finally attained the relatively reliable statistics on the compressibility of the spring.
The last one was the centrifugal primer-detonator.
It was also the device with the most technology in the fuse. Simply put, it embedded the detonator in a coin-sized half-circle iron plate. Normally, while being fixed by a spring, the detonator would stand in the middle of the fuse at an angle. With such a set-up as this, the firing pin, detonator, and explosive powder were not aligned. This way, even if the shell fell off from high above, the firing pin would not touch the detonator, so as to prevent accidental explosions. Only when the latch was separated from the lock in the second safety, could the iron plate be mobilized.
After being shot, the grenade spun at a drastically high speed because of the rifling in the barrel. Under the centrifugal force, the tilting detonator gradually stood upright, just like a spinning top whose center of gravity gradually closed on its axis line. This process completed after the bullet had left the muzzle for 200 or 300 meters, so even if the muzzle was stuck or the bullet ran into tree branches, it would not detonate prematurely.
When the detonator returned to the upright position, it aligned with the firing pin and explosive powder. Under this circumstance, once the fuse touched the ground, the firing pin instantly inserted into the detonator, and then the explosive powder pushed the super-hot gunpowder into the warhead, which in turn exploded the surrounding enemies into pieces.
The advantage of the centrifugal safety lay in the fact that if the shell failed to explode, without the centrifugal force the detonator would be popped back to its original tilting position by the spring, which made the retrieving work much safer.
Besides, if the entire grenade was grasped or accidentally found by the enemy, it could only be used as a normal solid shell when it could not get enough centrifugal force from not being fired in a conventional manner. As for tearing it apart and replicating it, that would be merely impossible.
"Prepare to fire. Start countdown at five."
An observer gave the order.
The repeatedly lengthened lanyard was gradually tightened while the gunner in the trench retrieved the rope bit by bit.
"Fire!"
As the gunner yanked on the rope, the ground instantly trembled.
A roar and fierce wind from the muzzle passed across the spectators' heads. Roland felt numerous soil particles rushed at his collar. Even if he had his ears solidly covered, he could feel tremors coming through his feet.
"Found the falling point. Explosion failed. Repeat. Explosion failed."
Lightning's voice came from the Sigil of Listening in Nightingale's hand.
"I see. We'll be right there," she replied and took out a Magic Stone.
"... We failed again?" Agatha said with disappointment.
"Failure is too common while experimenting." Anna consoled her. "As soon as we find the correct direction, we can guarantee success in mass production."
"Nicely put." Roland praised her while patting her head. "Besides, now with the help of Summer and Sylvie, the research and development speed is astonishing."
Even in modern times, it was common if thousands of shells were fired during the grenade testing, so to find any problems with two to three shots was like mission impossible.
Reaching the falling point of the bullet, Anna cut the fuse with Blackfire to ensure the safety of the payload. The soldiers then collected the failed shell. Either the gunpowder or the metal shell could be recycled, so it would be a waste to throw them away.
"Summer, it's your turn," Roland said with a gesture.
"Yes, Your Majesty." Summer nodded. Exhibiting her playback ability, the phantom of a shell that was about to fall to the ground instantly appeared in front of everybody.
Although Summer's magic power was still at a low level—after four months' of practicing, she could only use it four times per day—with precise control on the magic power, she could fix the playback image at an exact moment.
Such an ability was to perfectly replay the scene. In other words, Sylvie could see the inside of the phantom—except being intangible, it had no difference from the real scene.
With the help of Summer and Sylvie, Roland was able to determine the spring tension after only eight rounds of test firing.