Re: Low-Tech Forces, not necessarily in DSII

Chen-song Qin wrote:

> > ballista fires its projectiles (stones up to 120 lb, or 6-ft
javelins,
> > for the classical ones) in flat trajectories.
> 
> No. Actually it depends.  When fired from a city wall, the ballista
can
be
> flat, or probably more likely , tilted slightly downward.  But in the
> field, the ballista has to be tilted up to either reach the city wall,
or
> gain an acceptable range.  In the book "the Crossbow" by Ralph
> Payne-Gallwey (finally got his name), he specifically pointed to an
old
> drawing of a ballista that could not be elevated and said at this flat
> trajectory, the projectiles would probably travel about 50 yards and
fall
> down, if even that.  The force of the ballista simply isn't large
enough
> to push something that heavy in a decent flat trajectory.

With a "flat" trajectory I mean a trajectory where the projectile leaves
the engine at no more than 45 degrees from the horisontal plane - often
20 degrees elevation or so. Single-armed catapults often hurl their
stones, pianos etc at about 70 degrees (very high, steep trajectories;
it
is rather difficult to get them to fire at smaller elevations) whereas
crossbows, bows, and ballistae don't usually do this.

I haven't seen a ballista fired myself, but I've talked to some people
(at the museum Falsters Minder, Nykoebing Falster, Denmark) who have
built a replica of a Roman javelin-throwing ballista. They claimed a
range of over 200 meters in a flat (ie, non-lobbing) trajectory; I don't
know how big the projectile was though. (They have an entire artillery
park - a counterweight trebuchet, an onager, the ballista, and a
man-powered engine last time I was there. Unfortunately that was in the
autumn, and they only demonstrate the engines during summer :-( )

As for the force of the ballista not being large enough - there are
chronicle notices about ballista bolts impaling two or three mail-clad
men in one shot :-/

Regards,

Oerjan Ohlson
oerjan.ohlson@telia.com

"Life is like a sewer.
  What you get out of it, depends on what you put into it."
- Hen3ry