Part 14: A single horseman able to defeat 1,300; what's going on!? Maeda Keiji
Freedom. It's as though the word exists for Maeda Keiji. While he belongs to the Maeda family, he shows no interest in world affairs and lives for love. He cuts a flamboyant figure with a hawk's flight feathers in his hair, a monkey - Yumekichi - on his shoulder and an incredibly long sword on his back. I'd have liked to do the same once, but with his personality and skill he can probably be forgiven for living his life this way. I'll try to assess the strength of the 'Gorgeous Splendour', Maeda Keiji.
A master craftsman's idea
The long sword on his back attracts everyone's attention. According to the Sengoku Basara 3 Utage Official Complete Guide, it's known as a 'Choutou' ('Supersword'). Measuring from the screen of the game, the blade alone is 1.18 times taller than Keiji. Keiji has a large build, so if he's 180cm tall that makes it 213cm. About as long as a spear - and that's only the blade portion.
The handle is long too: 116cm, measuring and calculating the dimensions in the same way. From the base of the handle to the tip of the blade it's a first-rate sword of 329cm. Moreover, the blade's shape isn't simply a larger version of an ordinary katana. When measured from the game screen and the realistic illustration in Sengoku Basara 3 Utage, the blade is 13cm wide and 3cm thick. While the blade is 2.8 times longer when compared with the replica sword owned by this author, it's 4.3 times wider and 4.2 times thicker. Its width and thickness are greater than an ordinary sword would be if it were enlarged. The Choutou was probably created especially for Keiji by a renowned swordsmith; I wonder why he went about it this way?
This design is, in fact, scientifically plausible. Using the principle of leverage, the longer a cylindrical object is the more it bends, becoming easier to break. To compensate for that the width and thickness need to be increased to the power of 1.5 of the increase in length. Essentially, you'd want the width and thickness to be 4.7 times that of the author's replica sword. The swordsmith would have trusted in Keiji's swordsmanship and held back to avoid making the sword excessively heavy. Still, the Choutou is heavy enough. Calculating based on the replica sword gives a weight of 38kg. Since an ordinary Japanese katana is around 1kg, that's 38 times heavier!
How much physical strength does Keiji have in order to casually swing this around? Swinging a cylindrical object requires force proportional to its weight and the square of the length. To wield the Choutou, then, Keiji has the power of 300 people!
Greater than 'one horseman who can beat a thousand'
The Choutou on its own would be far too much for a normal warrior to handle, but Keiji takes things further still. By connecting the Choutou's handle to its sheath, it changes into the even longer 'Shuyari' ('Scarlet Spear')... and again, he swings it as though it's an ordinary katana. When the measuring and calculations have been done the length of the sheath is 286cm and its weight 13kg. Therefore, the Shuyari's total length is 499cm and its total weight becomes 51kg. The force to swing this is equivalent to the manpower of 1,300 people. Although there's an expression 'one horseman who can beat a thousand', Maeda Keiji would be a match for one thousand, three hundred!
However, this katana makes you respect the master swordsmith more and more. When Keiji swings the Shuyari, an enormous centrifugal force ought to be acting on the joint between the Choutou and its sheath. Though it's said that a professional baseball player's full swing moves at around 150km/h, if Keiji swings the Shuyari with the same amount of momentum, the speed of the tip will increase with its length and it will reach a speed of 750km/h. The centrifugal force at that time will be 26t. In other words, even though it can be disassembled easily, the joint between the Choutou and its sheath is so strong that you could hang 2.5 coaches from it. I wonder if the master who made the Choutou was surprised when he found out what Keiji required.
Feeling sorry for the enemy soldiers
Keiji displays superb techniques alongside the Choutou. 'Koitsudzuri' is amazing. It's a move where the Choutou is swung up to the left and right alternately from below, spinning the enemy in mid-air.
By watching the motion closely, the enemy continues to spin while travelling around 30cm in mid-air, vertically. They would probably rise up from below with a slash, then after dropping down they'd be repeatedly slashed back up again. The time taken for an object to rise up 30cm and drop back down to the ground is 0.5 seconds. That means that the enemy soldiers are being launched up approximately twice every second. I feel so sorry for them.
But if Keiji is swinging the Choutou left and right at a 90 degree angle, the Choutou's tip should be moving at a speed of 270km/h. When the slash comes up from below at a 45 degree angle, the enemy soldier should be lifted 950cm if an enemy weighs 100kg combined with their armour. Why does it only raise them up by 30cm? Perhaps some of the Choutou's energy is being channelled into spinning the enemies. When it's only raising them up by 30cm, the enemy's body will spin twice more every time it's slashed. It's increasingly heart-wrenching...still, considerable skill is needed to time the strikes well as Keiji continues the spinning.
Sometimes Maeda Keiji deftly tames the 38kg blade forged by a master craftsman, and sometimes he swings it with the brute strength of 1,300 people. While currently enjoying his freedom, if the day ever comes when he awakens and decides to take the country, he'll probably greatly change the balance of power in the Warring States.
Note 1: The title and the second section play on the famous Japanese idiom 'ikkitousen', which literally means 'one horseman who can beat a thousand', or more generally, a person who is tremendously skilled at something. In the title of this article, the idiom is altered to be 'one horseman who can beat one thousand, three hundred'. I wasn't able to make the meaning of this reference very clear in English; please keep that in mind.
Note 2: Due to the New Year holiday period, there won't be any more Sengoku Basara Science Laboratory articles until 9th January 2013.