Now that Internet has made some information widely available to those who sincerely search, it is generally admitted that O sensei was
highly trained with weapons and used that knowledge to create Aikido, especially after 1942.
Right from the start his training consisted in a mix of weapons and empty hands techniques. Most internet biographies
forget to mention that fact when they evoke his training in Gotō-ha Yagyū Shingan-ryū under Nakai Masakatsu
from 1903 to 1908.
For a long time, that reality was denied in order to fit the notion of an "Art of Peace" at a time when the Western world did not want to
hear about blood-dripping spears, weapons and swords… Also because many teachers were and are still not competent to teach them.
Then Internet was born and suddenly O sensei could be seen holding a weapon on half of the available pictures.
In reality, O sensei was awarded certificates of ken and spear mastery by his first teacher, Nakai Masakatsu (then by Takeda Sokaku in Shinkage ryu), he took part in a war and he was a fine bayonet fighter…
O sensei's kamae with the rifle, slighty modfied but still consistent with JUKENJUTSU
Background
The history of bayonet is extremely grim and interesting in many aspects. This Wikipedia article is a good basis.
The amazing thing is that for nearly 250 years, the bayonet techniques have not radically evolved. The same basics are everywhere and don't seem to have changed so much along the years, which is not really surprising, the human body having remained
the same... The variable are rather the size of the rifle and the blade's characteristics. Several books are easily available on the
web, some of them quite old like this one:
1853… 33 basic movements.
A classical 18th century bayonet charge would have probably looked like this.
The English Redcoats would walk straight to the enemy, knowing that, because of the loading time and the riffles' inaccuracy, only a fraction of men would be injured or killed. They would endure a few rounds of fire but they knew it would then become a bayonet fight and the Redcoats excelled in this (at the end of the movie, the screams signal the assault).
With time, because of their bayonet skills, the Redcoats acquired a reputation of invincibility, up to the point they sometimes just needed to charge and the enemy would surrender. For the bayonet inspires the fear of cold steel while a bullet is invisible, nearly abstract and brings death quickly… Bayonet is plain horror, plain disgusting.
...
Nowadays, the bayonet is outdated, but partly only. Some military corps keep bayonet training as part of their curriculum
because:
- it can be useful (as in Iraq 2004 - Cf. Wikipedia - by British soldiers, such a coincidence…)
- it builds up military qualities
One must not forget that drones may be useful but the last 100 meters are the infantry's domain and sometimes grunts end up fighting with whatever they find, including bayonet.
Technique.
The following film is extracted from one of these reality TV blah blah shows where UFC fighters (or similarly trained practitioners)
discover the US Marines training (a part of USM's recruiting propaganda: as they seem to experience issues these days, talking that way to young MMA fight-mooded young lads seemed a clever
approach…).
A couple of things can be learned here:
- a wide stance is wrong. One can't agree more with the drill instructor (funny how he refrains from shouting at
the poor sod). That wide stance is so common in Aikido nowadays (especially at the end of movements) that no one seems to notice anymore… 
However, it leads to using too much arms strength, induces a bad balance, etc, etc. Shoulder width, please, let's keep
it natural…
- keep your foot pointed at the opponent which has for consequences to keep your hips facing towards the opponent to develop more power and
stability. Etc.
But the bayonet drill won't surprise the practitioners who have studied the kumijos. For the described bayonet technique is the equivalent of the 1st kumijo (uke's "response" to first yokomen) mixed with number 3 of 31 kata - cut on the jo + tsuki (with the slight variation of the front hand position).
Following a discussion with Matthieu Jeandel, one could also explore the link between the bayonet drill, the first kata of kikishin ryu
spear and the ken tai jo series. Such a study (sorry no time...) could be really useful to understand the underlying realities of Aikijo.
...
In fact, the spear is a much more complex affair than the relatively simple(r) bayonet. But they share many points, including the capacity
to cut, to slash.
Technically, most bayonets are weapons with two edges. The slashing is limited to a few movements only (but, for obvious reasons, the
military only uses simple, straight-to-the-point moves). More importantly, the rifle itself does not allow any easy nor meaningful change of hands, etc.
It is worth noticing here that many yari actually have three cutting edges (triangular blade) and therefore allow slashing
in many ways (jodan gaeshi becomes much easier with this in mind). But, technically, there is no limitation to cutting with a two edged weapon, it is only a matter of proper handling,
positionning of the blade, although it requires more precision and skill.
This video is really good to figure out where Aiki weapons come from (at least culturally and one can read many common technical similarities…). Let's not forget the fundamental importance of the spear in Japanese culture (therefore most probably in O sensei's mind) since the country is said to have been created by a spear in Shinto mythology.
At the very heart of Aikido one can find very effective techniques and principles, totally consistent with military knowledge,
still valid and used / taught nowadays.
Arguing about weapons usefulness in Aikido is obviously irrelevant here: they are, in the same way as tai jutsu, part
of Aikido's DNA. Even more: the way O sensei synthesized them, bukiwaza and tai jutsu explain each other, like one living multi facetted entity.
This has huge consequences for bukiwaza and tai jutsu techniques, it is not only a jo 
.
Good keiko all !
