But I have my reservations as the blade is in surprisingly good condition...
This pic is posted at http://hfsword.com/bbs/viewthread.php?tid=...ghlight=&page=1

Changdao and its associated force structure during General Qi's time:
When General Qi was posted to the northern frontier to train the troops there to deal with the Mongols, he went on to establish small combined arms units (based on his experience in the south), adapted to localized conditions, besides repairing and enhancing the Great Wall.
General Qi had adapted an innovation from another General, Yu Dayou, who had used wagons as mobile fortification / defensive works as well as a means to mount cannons and transport them efficiently along the cavalry terrain of the northern plains.
This 100,000 strong army of General Qi was equipped with steel armour suits and helmets as standard and were divided into 4 components:
1) Combat Wagon Force (50% changdaos)
2) Baggage Supply Wagon Force (logistical support role) (50% changdaos)
3) Infantry Force (50% changdaos)
4) Cavalry Force (20% changdaos for Left and Right components, 27% for the Central component)
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The Combat Wagon Force and Baggage Supply Wagon Force were equipped with medium caliber (Chinese copies and modifications of portuguese breech-loaders) and smaller caliber cannons.
The "Commando Team" is the non-artillery combat component of the Combat Wagon Force and Bagguage Supply Wagon Force and uses the wagon as a large mobile armoured platform. It consists of 8 men:
1) 4 men with changdaos (an design idea inspired/copied from the 1.95 meter long nodachi of the Japanese pirates) and muskets (Chinese-made Portuguese-style matchlocks)
2) 2 men with shields and sabers plus muskets
3) 2 men with tridents and "fire-arrows" (arrows with rocket propulsion).
Upon contacting the enemy, the wagons are to be setup in a rectangular formation and all personnel are to withdraw within this defensive perimeter. After the cannons, muskets and fire-arrows are fired first at long range against the Mongols, the Commando Team would park their long range weapons inside, move out of the defensive perimeter and deploy in formation, using their changdaos, sabers and shields, plus tridents for close-quarters combat.
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As for the Infantry Force, it had divided into 2 equal and separate groups of musketeers and "close-quarters fighters" (General Qi calls them "killers" or "shashou"). The basic unit for both groups was 10 soldiers. The musketeers were all armed with changdaos; whereas the "killers" were armed with:
1) sabers and shields
2) multiple tip bamboo spears
3) tridents (also equipped with "fire-arrows")
4) long spears (also equipped with composite bows/arrows)
5) poles -- long heavy sticks tipped with a small double-edged steel blade (also equipped with composite bows/arrows)
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The Cavalry Force was divided into 3 components: Left, Right and Centre. As for the Left and Right Components, it was to consist of basic units of 10 men equipped with:
1) changdaos (also equipped with muskets)
2) poles with gun barrels-mounted at the tip *
3) tridents (also equipped with "fire-arrows")
4) another type of pole, this time with a slighter longer and single-edged steel blade (also equipped with composite bows/arrows)
5) poles (also equipped with composite bows/arrows)
* Known as "kuai-qiang", a short but wide-diameter gun barrel mounted on a shaft --- a design originating from the Yuan and early Ming Dynasties, where the soldier can use the weapon as a pole for close-quarters fighting after firing off a shot.
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The Central Component of the Cavalry Force is uniquely equipped as it composes entirely of light cavalry.
In the Central Component, at the battalion level of 3 companies, there will be one company (which will also consist of basic units of 10 men each) where the weapon allocation is:
1) 8 men with changdaos (also equipped with muskets)
2) 2 men with tridents (also equipped with fire-arrows)
The other 2 companies will also consist of multiple units of 10 each.
And each 10 men unit will consist of:
1) 4 men with single-handed sabers (also equipped with composite bows and arrows)
2) 4 men equipped with spears, specially designed with downward curving hooking blades on both sides of the spearhead -- to unseat enemy horsemen (plus composite bows and arrows)
3) 2 men with tridents (also equipped with fire-arrows)