「Hm? What are these?」
Marcia tilted her neck as the parts were not in the least like an oar. Jin,
「Well you’ll see. Reiko, help me assemble this.」
「Yes.」
Jin asked Reiko to hold the heavy parts while he attached them on the catamaran. Before long, it was completed.
「It’s done now! Let’s test it and take a look at the balance.」
It was attached to the rear of the catamaran’s central hull.
There was a turbine at the rear, and attached on the sides of the turbine were wheels. The wheels had a V groove in them and had a flexible belt attached.
The belt was connected to another wheel.
Another wheel had an L shaped rod protruding out from either side, slightly behind that was a seat and slightly in front of that was a handle.
You might already know it by now, but Jin had made a propulsion device that uses bicycle pedals to rotate the turbines. It was often a tourist attraction at ponds and lakes.
But having seen it for the first time, Marcia,
「How can this move forward?」
She was worried.
「Proof before theory, well try it out first.」
So, with the Golem Arrow’s help, we moved the boat to the sea. And,
「Well then, since I’ll be steering, Reiko, please do the pedalling.」
「Eh? Is that okay?」
Marcia was still worried, but Jin laughed,
「Yeah. Just leave it to me.」
「Oto……Onii-sama, I’m ready.」
「Okay, let’s go. We’ll take it slowly first.」
「Okay.」
Reiko stepped on the pedals. The turbine started to rotate, scooping the water to the rear. The boat started proceeding ahead with the recoil.
「Ooh! It moved!」
The boat then exited the swimming area and gradually picked up speed.
「Yep, this is quite alright.」
「Otou-sama, do you want to go faster?」
「No, this much is fine. Reiko, how much is your Ether Converter outputting right now?」
「Yes, it’s approximately 5%.」
「The efficiency is worse than I thought. Maybe we should change the shape of the turbine.」
Jin then sat in the cockpit and used 《Forming》. If there’s physical contact he can still use it at a distance of 3 metres. However, the efficiency drops inversely proportional to the distance.
「Oh, looks like it’s good this time.」
After fine tuning it several times, the speed had increased by about 30% compared to the first time.
「Alright, let’s return for now.」
Jin did a U-turn and returned to the dock. Marcia greeted them with a joyful smile.
「Jin! That’s was amazing! You’re a genius!」
Not restraining any of her praise, Jin was a little shy while Reiko was proud.
「It’ll be complete after adding one more thing.」
「It’s still missing something?」
Marcia asked for what Jin meant.
「Yeah. Since the turbine will spray water everywhere, we’ll want to attach a cover to defend against that.」
When the turbine rotates at high speeds, the centrifugal force would cause water to spray everywhere. Reiko and Jin’s backs had also been soaked wet.
「This goes likes this. 《Forming》. Okay, it’s done.」
「Then can I also give it a ride?」
Seeing Marcia who was itching to have a ride, Jin wryly smiled,
「Sure. But before that, the owner, Marcia, should give the boat a name.」
「Hm? R-right. Then… how about 『Cygnus』?」
「Sounds fine doesn’t it? Well then, to match the name 『Cygnus』…… 《Surface Treatment》.」
「Huh? Aaah???」
The hull of the catamaran, which until now had a wooden colour, had now changed to a white, worthy of the name Cygnus.
「Wha-what did you just do!?」
「I simply dyed it white.」
In short, bleaching. Although he had actually applied a water proof coating too. Next Jin,
「Arrow, come over here for a moment. Okay, 《Plating》」
He plated Arrow’s surface using the nickel he got when separating the impurities from the bronze. And so Arrow became silvery grey and resistant to corrosion.
「A-amazing! Jin, is it okay already? It okay right?」
Seeing Marcia who seemed like she could no longer hold on and wanted to ride,
「Yeah. Be careful.」
「Great! I’ll be going! I’m counting on you Arrow!」
「Yes, please leave it to me.」
「Launching 『Cygnus』!」
Because Marcia has the highest command priority, the cooperation between Marcia and Arrow was smooth at first. Then the boat abruptly started hopping.
There was a splash of water from the stern as it sailed across the water. Jin having seen that,
「Ah, as I thought, the efficiency of the water wheel still isn’t good.」
He said to himself. Reiko having heard that,
「Otou-sama, are you still dissatisfied with it?」
Reiko had been given the knowledge of the previous Magi Craft Meister, Adrianna Balbora Ceci, however the propulsion device Jin made this time was not part of that knowledge.
「Yeah. The efficiency improves as it operates similarly to oars, but if it splashes that much…」
Right, it starts losing it’s energy because of the splashing and waves. With Jin’s knowledge from modern Earth, he wanted to make a screw propulsion system.
「However, there are a lot of problems with rotating the screw.」
Firstly, the rotation needs to be changed to 90 degrees to the pedal. The rotation speed also isn’t enough. Unless the screw has a high rotation speed, the efficiency will be bad.
「It’s because I still haven’t made bevel gears yet…」
Up until now, Jin hasn’t made gears. Since at least 2 or more gears must mesh together, precise accuracy is required.
With ball bearings, the weight, that is the parameters were manageable to make. But in the case of gears, the module, pitch, involute curve and such were a bit out of his abilities right now.
「It can’t be made without the help of a machine.」
Since he had worked at factories he had used lathes and milling machines and knew the rough structure of them, however, without time he couldn’t reproduce them.
「Well, that’s a task for back at the laboratory.」
After a while, the 『Cygnus』 returned kicking up the water.
「Welcome back.」
When Jin greeted Marcia on the pier, she who was full of excitement,
「Jin! This boat is amazing! I’ve never seen a boat as fast as this!」
「That’s nice to hear. So, do you have any points that you’re unsatisfied or worried about?」
When Jin asked,
「Ah, no, I have no complaints on the propulsion. If I had to say, it would be the hull. A little more manoeuvrability would be great.」
Even though the catamaran can move straight ahead well because it has a long hull, it’s difficult to manoeuvre with sharper turns.
「Right, but I don’t think we need that manoeuvrability for the competition do we?」
「Well, that’s true. It’s simply out the harbour, turn and go around the island and return to the goal.」
However, Marcia had one more thing to add.
「It’s not a bad thing to aim for a better hull though, right?」
To Marcia who laughed and said that,
「You’re right. Since progress halts when you become satisfied.」
Jin also agreed.
It was nearing evening and the wind was also dying down. Jin and the others decided to call it a day.