FLTL Ch 241. Mechanical Advantage

A/N: I have attached a few images below the chapter which will make things easier to visualise. Make sure to take a look when needed. Enjoy!

*******

With Hyola out of the village, they only had two crossbows in Tiranat right now, which meant only two of the gates could be protected by them. Ideally, Kivamus knew that he should have asked Darora to work on making another crossbow so they could protect all the gates even when they had to send a crossbow to protect a caravan, but they really needed all the seed drills to be built first, since it was essential to finish sowing on time. That meant crafting another crossbow would have to wait for now. Hopefully, Feroy would be back safely before too long, so the guards should get three crossbows once again to protect the village after that.

As a temporary measure, they had decided to close and bar the southeastern gate until Feroy returned with all the guards, to make it easier on the remaining guards to protect the village. Otherwise they might have had to start pulling twelve hour shifts once again due to a shortage of guards, like they had to do a few times in the past. Right now, only the north-eastern gate and the south-western gate of the village were open, facing the roads going from Tiranat northwards to Cinran, and westwards to Kirnos respectively.

Seeing Hudan talking with the guards on watch duty at the manor gates, Kivamus called him over. "Do you have the guards ready?"

The guard captain nodded. "Of course. The horses are ready as well. We can leave right now." 

"Great!" Kivamus smiled. "Let's go then."

Taking over the reins from a guard who had brought the horses from the stables, Kivamus mounted the beast, while the guards climbed on their horses as well. Their small group exited the gates of the manor and started moving north, and before long they reached the north-eastern gate of the village. 

Right next to the gate, he saw Taniok hard at work with nearly a dozen other labourers. While the foundations for the watchtowers had already been dug before the ground froze during winter, one of the labourers was using a shovel to clear the pits of the snow which had gathered in them, where the pillars of the watchtowers would be planted after that. At the moment, Taniok was scolding an apprentice nearby who wasn't cutting the planks properly - which would be used to make the parapet and the roof of the tower. Some distance away, another man was guiding a pair of horses which were pulling one of the log-movers behind them, with a long and sturdy fedarus log attached to the primitive machine. Another apprentice was cutting some logs into smaller lengths, which would go on to become the supporting beams for the watchtower.

Noticing him, the old carpenter gave him a quick bow. 

However, not wanting to take any time from the carpenter who already had a long list of things to complete, Kivamus waved him off. "You can carry on, Taniok. We need the watchtowers built as soon as we can."

"I'll do my best, milord," Taniok nodded before turning around to scold a pair of workers who had sat down to rest, seeing that their supervisor was busy talking. "Get up, you lazy lot! I swear you can't even work for an hour before needing to rest!" 

Leaving the carpenter behind, Kivamus and the other guards kept moving north, before they found the fork in the road and turned east. The under-construction dam awaited them.

*******

"The dam looks much bigger than I thought it would," Hudan commented. 

"That can't be!" Yeden, the foreman of dam construction protested. "I've made sure that the workers are following the plans of Lord Kivamus accurately!"

"Oh, I didn't mean that you aren't doing your job properly," the guard captain placated. "It's just that I am seeing a dam for the first time in my life, even if it is only on this small stream, but now that it is getting close to completion, it just looks enormous to me."

While those two men were talking, Kivamus was trying to visualise where the water wheel should be placed near the dam - behind which water had already started to gather in a growing reservoir. 

With the help of the carpenter Darora and his apprentices, they had already made two strong wooden sluice gates on the front of the dam which were attached to a sturdy frame. Those sluice gates could be lifted with the help of a series of pulleys, which were installed around a meter above the frame of the gates, which were fixed securely into the dam. Right now, a labourer was winding a rope around the last of those pulleys above the first sluice gate, while standing on top of the dam, before he threw one end of it to another labourer waiting to catch the rope on the bank. 

"I really gotta see how this pulley system works," Yeden commented. "I know you have explained it to us before, but it still sounds incredible if it really works like you said it would."

"Well, you can see the benefits right now," Kivamus grinned. "I think the labourers are done installing the first sluice gate along with its rope." 

Yeden nodded and started walking towards the workers.

Hudan was frowning at the labourer standing on the stream's bank with the rope in his hands. "I know that there isn't any water behind those gates right now, so it would be easier to lift the gate today then it would be after the water has risen to the full height of the dam, but the planks of those sluice gates still look very heavy. I don't think even I could lift it by myself." 

"You can't," Kivamus shrugged. "Those gates were built to withstand the pressure from a lot of water, so they are a lot thicker and stronger than what we have used as planks in the longhouses. With the size of even a single gate being many times as much as a plank used in the longhouses, that gate easily weighs as much as three men, if not even more. Yeden had told me that it took half a dozen men to lift it properly into place before they could fit it into the frame of the sluice gate."

"I can understand that more men would be needed when trying to fit it into place then they would be if they were just lifting it on a flat ground, but still..." Hudan shook his head. "I don't think that a single labourer can lift it by himself." 

Kivamus grinned again. "Well, it's time to see the magic of mechanical advantage."

Reaching close to the dam, Yeden shouted, "Alright, let's check whether it works properly." He pointed at the labourer standing on top of the dam. "You! Stand back." Then he looked at the man holding the rope on the bank. "Come on, start pulling the rope now."

The labourer nodded and began pulling the rope with a noticeable strain of effort but he still didn't need the help of anyone else, and inch by inch the sluice gate started moving upwards. It was easy to see that the man did have to pull the rope a lot more than the height to which the gate was rising, but that is exactly how it was supposed to be. 

Before long, the gate had risen to as high as it was meant to go within the frame, with just that single labourer pulling that rope. Once he was done, the labourer looked confusedly at his arms, as if he was wondering when he had gotten so strong, before he used a loop on the rope and used it to toe the rope around a post dug into the ground to secure the gate in its current position, just like a mooring line which lifted a ship's anchor was placed on a bollard by a dockworker. 

A group of other labourers had stopped to look at the process as well, and seeing that their hard work had been successful, a loud cheer went out from them.

"By the goddess, it works!" Hudan breathed. 

"Well done everyone!" Yeden praised the workers, which led to another loud roar of success. Once everyone had quieted down, Yeden clapped his hands loudly. "Alright everyone, show's over now. Get back to work!" The labourers nodded while grubling and started returning to their tasks, while Yeden walked towards Kivamus.

The foreman shook his head in wonder. "It worked exactly as you said it would... It still feels incredible to see that a single labourer had lifted that gate by himself with the help of those pulleys, when it took a lot more men to lift the gate earlier." 

"That is the benefit of mechanical advantage, which that system of pulleys provides us here," Kivamus explained. "This particular arrangement of pulleys allows a solo man to pull up that gate by using a force eight times less than its weight, but in return he has to pull the rope eight times as far as the height by which the gate will rise." Noticing that neither of his listeners seem to have much of an interest in a physics lesson right now, he snorted and changed the topic. "Did Darora give you enough pulleys for the second sluice gate yet?"

*******

*******

A/N:

1.) A mooring bollard at a pier/dock, which is basically a sturdy post where a rope can be attached to hold something in place. In the dam's case the rope will keep the sluice gate up, so that water can keep flowing further.

------

2.) An illustration showing the mechanical advantage offered by a Block and Tackle, which is a combination of pulleys which allows a person to lift a lot more weight than he would be able to do otherwise. In the leftmost arrangement, a person will need to use a force requiring him to pull a weight of 100kg to lift something of the same weight, while in the rightmost one, he will only need to use a quarter of the force ( requiring him to pull an equivalent weight of 25kg) to lift the same weight of 100kg, but in return he will have to pull the rope four times as much as the weight will be lifted. This system can be used to reduce the required force even further.

3.) There is a sketch of a map of Tiranat which I made recently, and you can view it in this post: https://www.patreon.com/posts/fltl-character-125354153

It is hand drawn, and I don't claim to be an artist, but it should still give you all some idea of how the village looks from above.

4) I will also attach an image of the location of the dam where Kivamus is visiting in tomorrow's chapter when it is ready.

I hope you enjoyed the chapter! Take care!

Next chapter: FLTL Ch 242. The Dam