The Ballista

This afternoon the wind was down below what even a wetted cheek could feel.   Zero for all intents and purposes. Of course, our preparations are nowhere near complete, so there was no taking advantage of it.   But, somehow it was inspiring to see that such days do exist up here.

The brunt of our effort for the rest of this week will be squandered making up an excessive number of darts for our next field trip. It makes a chap just goosey thinking about all that lovely ammo we’ll have to experiment with.   To quote a famous Kiwi,  “Data!, Data!, Data!”. Nothing quite like it if you want to see inside a thing.

But, before we can bring our mean, meme machine into action, there is an issue we have to address.  It seems there is something of a death match going on between Firefly’s hand winch and the indelicacies of my failing carcass.

The lumbars are in revolt again.

Fortunately, I have a work around.

Thanks to the highly skilled and detailed planning that was incorporated into earlier parts of this project  (i.e. dumb luck) it seems possible to mount our trusty Warren 12 volt winch dead-on centerline, and still have enough room to operate the hand winch.  I have  a plan for a relatively quick attach/detach setup for the winch.

…And Ah!, …….. Lo! the waters parted , and blessed peace prevailed in all the joints of man.

Electricity!

All the items in this next spread weight 200 grams, right on the nose.

Those lethal looking fellows in black have all had their tips hardened to around 45 RC for about an inch back.  All the better to administer their mortal intent on the hardened armour of  any ancient adversaries we might care to dream up.   Eventually, we hope their biting touch will be felt  by all the usual catalog of Fourth Century defensive sheathing: helmets, shields, chainmail, breastplates, … after going through, maybe, a water-trough or two.

(Hmm… White Man talk big!)

For what comes next, however, they will not need their armour busting capabilities.   The choice of their weight, and their dimensional consistency, will be the qualities that shine in our upcoming bench rest experiments.

…That, and the sweet-still air of a placid summer afternoon.

For long range precision, when all the little impediments have been sorted, the air is everything of substance.  Woe betide the shootist that ignores a petulant weather god.

Some controlled profiling on these heads has made it possible to put their weight right on 200 grams, plus or minus a quarter gram.

While these heads are unapologetically machined to our purpose,  my decades of experience with hand filing, tells me that ancient craftsmen would have had little difficultly matching weights by the rapid removal of material in that turned back-taper seen above. (Of course, it is also possible that ancient marksmen produced matched sets of bolts by simply sorting  the available supply by weight.)   In any event,  as our purpose is to see what the best of the best in old Rome could do with their ballistas,  we prepare as they would have.  With as much uniformity  as possible.

This next test will be like shooting a bench rest group with a firearm.  One conducted at 800 plus yards, with a windless day mandatory.  The whole purpose is to tune into existence, the most tightly grouped cluster of shots possible at this extreme range.  This will help define the physical limits to the degree of precision we might expect the Romans to have been able to utilize.   Accurate shooting is always about pattern control.

Here is a prototype assembly for what I hope will become, standard fodder for Firefly.   It is serving to ferret out any more “changes of mind” that might arise, before committing to a production run of perhaps a dozen projectiles.

Clearly we are not attempting to make this bolt a paragon of handmade virtue.   We need too many of them, and all nicely matching, for anything so refined as that.  They’re just reasonably authentic analogs that will be subject to the kind of abuse that makes their relatively rapid manufacture a necessity.  The tough plastic fins that can withstand multiple firings are the surest example of this pragmatic approach to data collection.  Definition is everything.

The finished weight of this new, pyramidal style head, came in at 210 grams, which is 37 grams heavier than the 173 gram bodkin used on that bolt we kicked out to 845 yards in that first round of flight testing from a few weeks ago.   The total weight of that bolt was 467 grams. This newly assembled bolt, tips in at 493 grams and is 34 1/4 inches long.  I’m guessing that the extra mass will reduce it’s range down to 800 yards.  That will still be ample for the type of long range accuracy trials we hope to start soon.

Previous experience suggests this bolt has an appropriate distribution of weight forward, and it seems to produce a nice stable flight pattern;  witness: zero oscillation in the tail of the bolt for as far as the naked eye can track it.  No reason to suppose it does not retain this virtue right up to terminal impact.

Zero oscillation mayhem, as it were.   Just about as remote a thing from Conan’s mind as possible.  “A bolt from the blue”, you might say.

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The Rebecca has requested her own personal set of Duras, complete with the thinner style of foreshaft and stubby little fins.  The shafts will be painted in the same colour as her favorite set of arrows,  “Duck Egg Blue”.  Here is a photo of the only existing example of an original and intact ballista bolt  that was excavated in the ancient Roman city of Dura Europos. (Phot0 from Duncan Campbell’s book)

Apparently there will be bonus points if I can get her little blue hatchlings out beyond the 1000 yard mark.

Lucky me!

This bulbous style head seems like it might not be such a darn problem to extricate from the tough topsoil around here.

Last time out, one of the bolts was equipped with a bodkin point, much like the original head from the British Museum seen in that posting from yesterday,  and after its 845 yard sojourn downrange, it required some enthusiastic counter-mining  just to get it’s eleven inches of buried length to wiggle around enough so the whole thing could be pulled out of the ground intact.  The design seen here is intended to reduce penetration and make extraction from the ground a less arduous process.  Better start cross- pinning the heads.  It’s no fun if the head detaches at the bottom of the hole.

After all, if we have a dozen bolts sticking out of the ground,  I don’t want to be playing   “groundhog day” with them all afternoon. You’ve got to think of these things when the youthful-vigor of your lumbars takes sabbatical.

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Update:  Nope! don’t like it!  Back to the drawing board.  Maybe something more like one of these originals found on Wikipedia.

The notion that blogs, as a medium, constitute a “public, private space”,   is amply demonstrated by all the ungainly fidgeting around that goes on here.   Our aim in these pages has always been to catch the ricochets as well as the direct hits.  Journal writing requires an extensive commitment to the mundane.

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Update:   …..

… Well, maybe.

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Update:  Almost had it right that last time, but the weight (as calculated by volume from the solid model)  came in at .454 pounds. The target weight I’m after is .375 pounds.  That should yield a  nice, relaxing, 850 yard range for our maximum distance accuracy tests.  And so, we tweak the model a little ….

These babies come in at .376 pounds each.  Good enough for government work.   The square portion of the head has a more acute angle to it than the previous version.

You see, every blessed little detail.  It just goes on and bloody on, doesn’t it?

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And from that classic 1933  movie,  I’m No Angel,  we have this rug pulling wisecrack to consider:

Eddie Arnold —  “Tira, I’ve changed my mind!”

Mae West (in her unique, laconic drawl)  —  “Yeah, does it work any better?”

The great wormgear of actual business type work has turned the corner into completion.   Glory be!   This means chips will soon be a flyin’ on some groovy new bolt heads.

I have some half-baked idea that if those notches around the triangular base of the bodkin are filed in by hand, then possibly this might provide an advantageous way to adjust the weight of the head, and thus allow it to be entered int0 a carefully measured and “adjusted”  group of similarly heavy units.  In short,  a matched set.

In keeping with our maximization of every blessed thing related to performance — philosophy, we might as well see if we cant make ’em match for weight  by a 1/2 gram or so before having to resort to hand files.  Should be a snap on our trusty CNC lathe.

..Well, you have to take some things as givens.

And then be thankful for them!

A few feet west of the Little Catapult Factory, and buried in the rock Excalibur-like,  we encounter this sturdy fellow.

This royal throne of weedery, this fissure filled with life, this happy breed of  plant set in the graying granite, which serves it in the office of a pedestal, or as a castle defensive to a goat , ….. This blessed plot, this earth, this realm,  this Verbascum  Bombiciferous !

I am forever amazed at how nature abhors a vacuum.  In weeds, in birds, in bees, in everything.  There are no second place winners if the niche in the rock is small enough.

Rhetorical dogmas are equally exploitative of their natural environment as any weed clinging to a rock, and the supposed sapience of our species does not seem to venture very far from home once the roots go down.  What was it Twain said?   “Tell me where a man gets his corn pone, and I’ll tell you what his political opinions are”.   When belief has settled in the mind,  how can we ever know if it is not merely the tenacity of nature expressing itself?  If we triumph in being rational and objective creatures, this insidious truncation of outlook is something to be keenly watched for.   Truth is always, coloured by the niche we inhabit.

This little item showed up today.

It’s a new laser rangefinder with the capacity to measure out to 1600 yards.  At least they claim it will go that far if it is measuring off a reflective target,  however,  my backyard testing indicates it works fine out to 900 yards if it’s bouncing off evergreens.  My previous one wasn’t much good beyond 200 yards, and we’d have to do a minor relay event to make it out to Firefly’s maximum range.

Anyway,  we’re all agog at how cool it is.  Hey Richard, did you know that your pole barn is 673 yards away from my back porch?

…..Settle down,  you know how I like to ponder hypotheticals.

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And as we move into a new bolt-making extravaganza, our thoughts turn to this little item from the British Museum.

The Catapult Gods are hard taskmasters,  but at least they have set us firm on another round of  maximum range testing.  Wood and metal chips must fly before we can again punch holes into a bright, blue sky.  Sometimes a change in work is as good as a vacation.

I take the liberty of copying this interesting description of the Fourth Century, Roman fort at Orsova,  from Dr. Gheorghe’s web site, The Alexis Project,  http://alexisphoenix.org/orsova.php

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a) Zernes-Dierna Roman Castrum

The castrum is located west of the river Cerna. Due to its small size, the layout was originally considered to be the medieval fortress of Orsova.

The dimensions of the fortification, identified in the field, are 64 x 54 metres and the time is late Roman, during the reigns of the Emperor Diocletian, 284 to 305 AD and Constantine the Great, 306 to 337 AD. North of the fortress late Roman bricks and tiles bearing stamps were discovered.

In the barrows of the NE and SE of the late Roman fortification level are ceramics from the 5th to 8th centuries AD. (studied groups are between the 7th and 8th, 8th – 10th, and 10th – 13th centuries).

b) Roman City

It seems that Dierna developed as a civilian city, without a military garrison. It did not exceed the rank of municipium. A late Roman fortification civil settlement partly overlaps the ancient Roman city. Other constructions were investigated on different occasions (Danube Avenue Alley, 23 August Street, Decebal, Graţca Valley were on the site of the first cemetery, with the second cemetery near the Cerna Bridge).

We know that Roman habitation concentrated in two areas: the first stretching along the river, and the second between the two cemeteries. Bricks in the town were found only for the 3rd and 4th centuries AD. A double pattern representing the goddess Minerva shows the existence of official local military forces.

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So apparently the footprint of the early fort was 64 X 54 meters.  At that range the ballista fire from the projecting towers would have been murderous for anyone trying to scale the walls.   If the barbarian leadership led its assault from the front, cutting down a few chieftains,  may have checked the general rush.

Or, not.   They were a pretty individualistic lot up in the northern tribes.  The expectation of a  good slathering of personal glory probably went a long way to seeing a lot of them “over the top”.   Maybe they didn’t lead their attacks chin first, and the high value targets hung back, the success of the venture depending more on how much collective mead the hooligans had been drinking, or mushrooms they’d been eating, the night before.  It seems clear, at least,  that the inducements to brave Roman ballista fire must have been particularly stirring.   Perhaps seeing their fellows cut down from a distance by a weapon as cowardly as a ballista just incensed their individual warrior spirits and made them fight all the harder;  not unlike the situation with modern, weaponized drones, where the tactical effectiveness of the device is often countered by its strategic usefulness as a recruiting tool for the very uprising it is attempting to suppress.  Sort of a, “shoot them in the head and they will come”,  kind of a thing.

No answers here, of course.  Just boorish ponderments for armchair generals to ruminate on.

“Hearts and minds!”,  me hearties.  “Hearts and minds!”

Back in the 1970’s, when the region of old Orsova was flooded  to make possible a new Hydro electric facility, the old Roman Castrum in the middle of town, was submerged for good.  Pity really.  Especially for all us torsion nerds that quiver with interest at the mere mention of late model, iron frame, Roman ballistas.  Who knows what other delicious catapult artifacts may have been found,  lurking underground for the last 1600 years? — Just waiting to be discovered, but denied us by the rising waters.

Here is a photo of our sacred objects from inside the National History Museum of Transylvania, located in Cluj-Napoca, Romania.

Is that a pesky outswinger  I spy over there in the corner?  Honestly!  Kids and industry!  You send ’em to college, give ’em an education ……. an’ whata-ya- get?  …. outswingers!  Grump! Grump! Grump!

Photo by Cristian Chirita.

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Anyway, new subject:

There is an excellent resource online to learn more about the locale in which the Orsova artifacts were found.  It is:

http://alexisphoenix.org/orsova.php

Dr. Gheorghe runs the Alexis project, which does a lot to elucidate out-of-towners like myself about the geography and history of the area.  Don Hickock is the webmaster for their site, and has been very helpful in providing  maps of old Orsova  before it was inundated.  One of these maps specifies the orientation of the four walled fort as it sat next to the Danube.  The spot marked in red shows the  projecting western tower, where the kamarion and single field frame were found.

And here is the larger version of this map that contains nomenclature for the fort with it’s four projecting towers.

And finally, here is a map from 1940 that gives some idea of the old fort’s relationship to the original water course.  The grid lines represent one kilometer.

The gold circle is the site where the artifacts were found. The blue circle gives a rough idea of the 892 yard, (815 meters)  maximum range Firefly is currently exhibiting.

Baatz, had this to say about the dig itself :

Just eyeballing it, the eastern wall is  perhaps a scant  sixty yards from the ancient water course.  This would still allow the south-western tower  to cover a large patch of the river towards the south with direct fire, as well as being able to sweep inland with it to the west and north west.  By indirect fire, that is shooting over the opposite wall of the fort itself, this one tower could still cover the remaining parts of the circle;  other, of course, than those bits directly below that opposite wall. If all four towers were equipped with inswingers of the Lightning class, the Romans would have been able to project a web of criss-crossing, anti-personnel fire from range zero (by virtue of the projecting towers),  out to a very long distance indeed.  (No projections on  maximum Roman ranges until we receive confirmation of the Samuli factor.  That is: the nylon/sinew propulsion ratio)

In the meantime,  there is more data to harvest out on the firing line.

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