Levi Porphyrogenitus, on 24 February 2014 - 08:59 AM, said:
For that matter, Katanas are almost useless against decent mail armor, let alone the heavier varieties. Katanas are for killing the civilian conscripts with their spears and farm implements (or for dueling when neither of you wear armor). You use your bow or your giant spiked club to kill other armored samurai.
Really, hatchets make the most sense for battlemech melee combat, though maces would probably do pretty well (specifically flanged designs).
Both in the European and the Japanese medieval history, swords were always a secondary weapon. Swords, especially those that weren't viable for stabbing (the most reliable way to pierce chain mail) lost much of their effectiveness with the advent of chain mail and the more effective the mail became. And once plate armor popped up... you were basically screwed in a fight against another knight because your only chance was to poke your sword through one of the very few weakspots in the armor, while the other guy could merrily beat your limbs or skull to a pulp with his axe/mace/hammer/halberd with impunity. Same goes for Samurai Armor (and to the Ashigaru torso armor to some extend): While they were lightweight compared to European armor and weren't especially thick, they were excellent as far as their ability to make blades glance off goes. Unless you were using longer and heavier versions of the katana designed to cut through armor (like the Nodachi), that weren't that flexible as the other long weapons, you weren't using your katana unless you lost/broke your main weapon (still better than a dagger). That means that you were traditionally using either a Yari (best at piercing armor through thrusts) or Naginata (longer reach and more force behind your slashes, also very efficient for hacking your opponents legs off which basically decides the fight) or a bow. You also used those weapons because you didn't want to put yourself at too much of a range disadvantage fighting against the common conscript soldiers that used longer versions of the Yari.
The Katana only became relevant in the Edo-period because you simply couldn't run around with a naginata as part of your casual/civil outfit, there basically was no war to be fought and the standard Katana was excellent for cutting anyone without armor.
Or in other words: Unless the weapon has a massive energy/plasma field that does the actual cutting: giant mecha swords are as useless as it gets for fighting mechs. Unlikely that FASA gave it much thought for the sake of coolness in the 80s (giant robo fighting another mecha with a sword) though. Axes and maces are better but weapons like the PPC are most likely more effective and deal their damage at range.
Edited by Ragnar Darkmane, 24 February 2014 - 12:06 PM.