 |
Warrior Ancient and Medieval Rules A Four Horsemen Enterprises Rules Set
|
View previous topic :: View next topic |
Author |
Message |
Mark Stone Moderator


Joined: 12 Apr 2006 Posts: 2102 Location: Buckley, WA
|
Posted: Mon Aug 29, 2005 8:02 am Post subject: stone throwers |
 |
|
--- On August 28 Jon Becker said: ---
> Ok - what exactly is a CHINESE 3 Talent Stone Thrower? Anyone have any
> pictures or reference sources to recommend? Anyone know of any good makers
> of a CHINESE miniature in 25mm for these artillery beasts?
Disclaimer: IANACH (I am not a Chinese historian).
A talent is a measure of weight, dating back to Babylonian times and --
measurement being a rather inexact science back then -- ranging anywhere from
75 to 140 lbs. Assume the lower end, 75 lbs, and you'll see that a 3 talent
stone thrower is capable of heaving a 225 pound rock a distance of 480 paces,
or somewhat over a football field in length.
To my knowledge, there is only one non-gunpowder war machine capable of
achieving this feat, and it's the trebuchet (not to be confused with the lesser
catapult or mangonel). The trebuchet uses some very clever principles of
leverage to hurl a heavy object a long distance. It basically relies on a short
fulcrum arm with a really massive counterweight rotating a much longer arm
through a much wider arc of rotation. To top it off, you add a length of
leather/rope/cord to the end of the long rotating arm, creating something
rather like a giant-sized staff sling, thus giving the less massive but still
heavy projectile tremendous velocity when it transitions from angular momentum
to straight line trajectory at the release point.
Now, this all sounds simple enough, but in practice it's quite tricky to design
and implement. I discovered this the hard way when I attempted, with limited
success, to build a scale model (only eight feet in height) at Burning Man
(http://burningman.com) a couple of years ago. Calibrating the whole thing so
that it actually releases at the release point is quite tricky. And the thing
sustains such tremendous force with each shot that it has a tendency to shake
itself to pieces through repeated use, no doubt accounting for the rationale
behind building these machines on the spot rather than hauling them around.
You can get a pretty decent depiction of a trebuchet at:
http://www.castlewales.com/trebucht.html
And, of course, more information than you're likely to want at:
http://www.trebuchet.com
-Mark Stone
|
|
Back to top |
|
 |
Ewan McNay Moderator


Joined: 12 Apr 2006 Posts: 2779 Location: Albany, NY, US
|
Posted: Mon Aug 29, 2005 8:07 am Post subject: Re: stone throwers |
 |
|
On Mon, 29 Aug 2005, Mark Stone wrote:
> Now, this all sounds simple enough, but in practice it's quite tricky to
design
> and implement. I discovered this the hard way when I attempted, with limited
> success, to build a scale model (only eight feet in height) at Burning Man
> (http://burningman.com) a couple of years ago. Calibrating the whole thing so
> that it actually releases at the release point is quite tricky. And the thing
> sustains such tremendous force with each shot that it has a tendency to shake
> itself to pieces through repeated use, no doubt accounting for the rationale
> behind building these machines on the spot rather than hauling them around.
Getting off topic, but I'd echo the caveats to anyone attempting to build
these things. I've done so twice - although the first, in high school,
would require a pretty damn wide definition of 'done so.' The second,
under the rubric of the SCA, was a huge success (and fifteen feet tall),
hurling the requisite cow a la Monty Python, but took an inordinate number
of people a very long time. Like, a couple of weeks, on average, for
maybe ten folk. Three of whom, fortunately, were structural engineers .
e
|
|
Back to top |
|
 |
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You cannot download files in this forum
|
Powered by phpBB © 2001, 2002 phpBB Group
|