Chinese Repeating Crossbow

Crossbow

A very crude and simple reproduction of a crossbow illustrated in The Book of the Crossbow.

This crossbow was one of the earliest repeating weapons. By cranking the cocking handle rapidly back and forth, a stream of crossbow bolts are fired.

Construction is extremely crude - the stock ("tiller") is laminated from plywood.

The bow ("prod") is made from a single piece of ash. It's a flat bow, curved only by tension in the bowstring. The design of crossbow really needs a steam-bent bow with a little more curve to it, to reduce tension (and thus friction) when the bow is uncocked and the magazine is sliding forwards. I know very little about bowmaking and this is the least effective part of this crossbow.

The bowstring is several loops of Kevlar bowstring, a loosely-twisted waxed roving. To resist wear, the central section is served with a wrapping of more bowstring.

Bolts are cheap chopsticks, either bamboo or plastic. They're cheap and disposable! Despite the very poor bow I'm using, it still has enough energy to shatter a plastic chopstick.

Action

The crossbow is a manually-cranked repeater. A large handle on the top is racked back and forth. Bolts are fired from the box magazine, which holds up to a dozen.

There is no manual trigger mechanism. As soon as the action is fully cocked ("in battery"), the nut fires automatically.

Moving the magazine forwards

Cocking begins by pushing the handle forwards. The whole box magazine and firing tray move forwards together, sliding over the stock. The bowstring slides backwards along a groove beneath the magazine and underneath the bolts.

Fully forward

When the magazine is fully forward, the bowstring drops into a notch at the back of the firing groove. The bowstring is now behind the lowest bolt.

Drawing the bowstring

Bringing the handle back pulls the magazine back, drawing the bowstring (trapped in the notch) back with it.

Almost firing

As the magazine returns to battery, a small peg in the base of the magazine is pressed upwards by the stock. This peg pushes the bowstring out of the retaining notch, and releases it to fly forwards, firing the bolt.

Links

• A reproduction of the relevant chapter of Payne-Galwey
• A '40s American plan for a similar crossbow, published by Popular Mechanics

Source Material

• The Book of the Crossbow Ralph Payne-Gallwey Paperback - 400 pages 1903 - reprinted 1995 Dover Publications 0486287203 A facsimile reprint of The Book of The Crossbow. Surveys the history of the crossbow with comparisons to the longbow, shortbow and handgun; the construction and management of medieval and modern crossbows; and the ancient and medieval siege engines.
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