Garrison Keillor once said that if you write about it, there is really no such thing as a “bad” day. It is all just material.

I am trying very hard to remember that as I review the results from testing the new paddle limbs. The added weight from their full length steel braces appears to have reduced the performance of the machine from around 400 fps down to 300 fps.  The earlier scalloped limbs weighed 7 1/2 lbs each, while the paddle limbs came in at a whopping 13 pounds each.  These heavier  limbs held  up to 4300 lbs of draw force brilliantly, but the extra weight  killed any performance advantage from the more powerful draw. I am starting to wonder whether the Romans ever actually used full length steel braces on their ballista limbs.  Heron’s description of  steel reinforced limbs with hooks for the bowstring,  seems clear enough in his writings about the cheiroballista. Perhaps his description was nothing more  than disinformation  designed to protect military secrets ………  Nah!

Perhaps my own prejudice to always seek out the highest level of performance is affecting my objectivity. But there really is no fighting it.  It is just flat out unacceptable to me to settle for 300 fps when I know 400 fps is achievable.  The only comfort here is to think that my counterparts in ancient Rome would have been similarly dissatisfied with these results.   It seems that the only way out, before  I become neck deep in a pile of mediocre performing limbs, is to retrace my steps back to the original lightweight scalloped limbs, and then upgrade them only in the areas where they actually failed.   This is something I should have tried in the first place, but I got a bit lost in trying to make old Mr. Heron happy.

It will still be necessary to use some steel in a new set of scalloped limbs, and I need to improve my forging capabilities to execute the plan I now have in mind.   Accordingly, I have spent the last couple of weeks acquiring some more blacksmithing gear.   A propane powered forge should show up in the next couple of days.  This is something I planned to do anyway, so the timing for all this really couldn’t have been better.

Leave a Reply