Get ourselves a bolt in
Hi it's Tod from Tod's Workshop and Tod Cutler here and today I'm back with this Roman catapulta.
So this is a piece of Roman siege artillery that will go very nicely with my trebuchet, side by
side. Obviously completely different periods because this one is about what, about 100 A.D
something like that. Trebuchet is of course about 1300, 1350. But this was sitting in my cupboard
and the Slo-Mo Guys came to me a few months ago for their new show "Slo-Mo Guys Big Adventures" on
Sky TV and asked if I had some interesting things to film. Here we are. I made it 10 years ago I
just never made a stand for it so I never even shot the thing, so I dusted it down, made a stand
get to play with it. So they've had their turn and now it's our turn. So we're gonna film this thing,
we're going to tune it, we're going to talk about the engineering, we're going to shoot it,
we're gonna see what it does. So I've built swamp racers, I've put jet engines into motor boats,
I've built electromagnetic cannons and I was asked to build one of these, to head the project,
head the engineering team to build a double sized one of these. So this is what's called
a three-span machine and it shoots the bolts that are about this long we built a six-span machine,
it's TV, you always build it bigger don't you? and the Romans never built it that
size but who cares?, it's TV. So just have a look at this clip where we started to test it
All right
Now the first thing to do is to clear the air because I have called it a catapulta,
not a Ballista. Now half of you are going to be screaming at your screens at this point going
"Its a Ballista!!!" Let me explain. So the Romans had many kinds of torsion artillery
the ones that shoot rocks and balls out of a bow type arrangement like this
are called ballista. The ones that have a single arm that swings forward with
a sling on the end, onager, they throw rocks, both of those kind.
Catapulta throws spears or darts, arrows call them what you will, pointy sharp things that look
like that. Ballista, ball. Catapulta, arrows. Okay? Later on of course you get other sorts
of problems in that we lose the terms and so you get to the Medieval world and you go catapult yes
that shoots rocks okay nobody's quite sure what a catapult might be, but anyway they throw rocks,
we know that. And then you get other terms thrown around like a scorpion. What's a scorpion? Well a
scorpion is a one span version of this, it shoots darts that are about this long. It's
the same machine and we're going to come and talk about the engineering of these things in another
film later on because they are fascinating, but you make the same machine just a different scale,
that shoots bolts at this length or bolts of this length or of course the two-span version
of that length. I am adamant that this thing is called a catapulta and the reason for that is the
TV company found an expert for us, somebody who could come along and guide us in the building.
It wasn't just a random dude they found down the pub, the man's name was Alan Wilkins and three
men were instrumental in putting a book together. Len Morgan, Alan Wilkins and E.W Marsden to write
Roman and Greek artillery, this is the second volume and if you don't know it and you want
to build these things, go buy it. It has every detail, every number, every size that you could
ever want for building these machines. Priceless absolutely priceless and it was a pleasure to
spend a week with Alan Wilkins. Lovely guy, but as far as I'm concerned he called this
a catapulta and if he calls this a catapulta and he literally wrote the book on them, that's good
enough for me. I still haven't really answered why I made it. I made the first one because TV paid me
to make it and it was great fun and it really was it was a really interesting project, but I
was so enthused by that project and meeting Alan Wilkins and just talking to him about all these
things and understanding more about something that I didn't really understand anything about,
I just wanted to come away and make it you know. The simplicity of it, the complexity, the beauty,
the concept behind it, the structure and the logistics that the Romans used to run these
things when in the nicest possible way English people were living in mud huts and they're issuing
artillery manuals for where you can site these things. Just blew my mind and I needed to get
involved and make one, but also in a very geeky engineering way, I love to find out things and
this is one of the only pieces of engineering that I've come across that scales up and scales down
and what I mean by that is if you imagine something like a jumbo jet,
if you build it three times the size it doesn't fly three times as fast, it doesn't do that,
engineering doesn't work like that, but these machines do. You can build a one-third size
one and all the timbers on it, one third the size, everything's one-third the size,
shoots 600 meters. You build it three times bigger, everything is scaled up, three times
the size, it fires 600 meters. Some of you out there are going "Uh yeah? what's the fuss about",
other people out there are going "Wow that is amazing", take it from me it is really unusual.
And I wanted to get involved in this world, so I came back and I made it, but I'm also a busy
guy and I just never got around to quite finishing it, did all that, never made the stand and so in
truth actually that's why the stand is a little bit off from the book, it's not quite right,
but it got the job done. Sorry I've rambled for far too long, so it's time that we go and shoot
it but I'll load, it I'll talk about it, while I'm doing it and then we'll go on a tour of the
machine. So we're going to pick up this machine as if it's just been shot, so we lift up the ratchet,
you then got the ropes here on the winch mechanism, you pull that, give it a bit of slack,
now you can slide the whole trigger assembly forward. Now this is the way that all Roman
and Greek artillery seem to function the Romans of course copied the Greeks and then in later times
this trigger system seems to have been abandoned by the Romans
but around about 250 the arcuballista, which is a Roman crossbow started to come in,
the trigger system still worked on siege artillery, but the smaller things
they move to a rotating nut as far as I can see.
Now you can see that the power of this machine is really quite low, I shouldn't be able to do that,
I've just got it out of storage, I'm just trying to learn it, trying to learn the machine,
make sure it's not going to kill me because there's a lot of pent up power here. I don't
know when this is fully tensioned what kind of power is going to be in this, what kind of
draw weight. I would think several hundred kilos and that's a lot of pent-up power. So now though
it has got hard enough that I need to move to a single movement, I can't twirl it round and round.
I think another couple that'll do this I think but I can promise you it will be
getting very scary once we tensioned it fully up so now the bolt goes in.
And quite simply pull the cord.
Let's start our tour with the engines of this machine, the torsion bundles. So a bow a long bow,
crossbow is flexion, it's a spring, it bends. These ones twist, that's what gives it the
motive force, so you put a stick through the bundle, you pull it, it wants to flick back.
Flick back hard in the case of this one, because at the moment I've got very little tension on it,
so I've got the pre-tension from when I strung this, but no twist on it, and I can get that now
that far and I'm giving it maybe 40 kilos something like that, 90 pounds in draw weight.
It's going to go up a lot from there because a little bit of twisting here makes one heck of a
difference here. Then we've got two laminated ash arms, curved, in a plated oak headstock,
so this actually dates it, the earlier ones weren't like this. So you could increase the
power, increase the draw length, but well with the power stroke, but we're going to come into that
in later films talking about the engineering. We have the brass washers here, you can rotate them
and then you can drop pins through to stop them unrotating and coming back and that's how you add
your pre-tension, but we're going to go around the front now and look at the faceplate. Now when we
come to the front of the machine here we've got an armoured plate, so you've got a decorative
rapousse brass plate here with a god on it, under that is a steel plate because those bundles are
enormously tensioned when you put them in, then you put the arms in, you put a pre-tension twist
on them, other way actually, pre-tension twist on the washers and then of course when you draw
the thing back you put even more tension on them. A sling stone in there, an arrow,
a spear, another catapulta dart, a ballista rock. All of those things will just absolutely destroy
that bundle because it is under so much tension, you've got to protect it. Now the Romans also were
very good at intimidating people, very good at being cool, having the best kit, looking good,
so why not put a god on the front that can spit the darts, because that's the sort of thing
that they did and they were they'd write on on sling stones. I bet they wrote on the darts too;
just looks awesome. The next important thing is the trigger system and the slider,
now this winch rope here it pulls the trigger back and the slider is attached to the trigger,
so it's not this flimsy little bit of wood here sitting in a dovetail, that's being drawn,
it's the whole trigger that's being drawn, so the bolt comes back, fits between the forks here
and that bar comes in underneath it. Will not, cannot go anywhere,
doesn't take very much with a bit of grease, it doesn't take very much to open that bar. The rope
will then slip out from under the forks. It really is beautifully simple, but it's a trigger system
that is ultra reliable and takes really high loads and anybody who's involved in building triggers;
triggers that take high loads through them are difficult to achieve to make them easy to work,
these are easy to work. Roman Greek geniuses. And the last part of significant importance
is the windlass. So what you do is you lift the ratchet bar up,
you've got the ropes here and you pull them because actually sliding the trigger forward
is always a bit difficult on this sort of device, you just help them along a little bit, you slide
it forward, trigger goes up, bar comes under. And here you have the ratchet, so really aggressive
teeth in here and a similarly aggressive tooth on here, hundreds of kilos of draw force,
you don't want this to give up when you're not expecting it, nice bit of weight on there goes in
and it just drops itself down, so there's no springs on it it's just purely gravity,
but what you do have is a very positively engaged system it will not fail. We'll talk
our way through the loading and shooting procedure again but now you know a bit more about the parts,
so ratchet off, slacking the winch, slide the trigger forward, down with the forks,
in with the bar, just making sure nothing is too tangled, dropping the ratchet back in.
and winching around
get ourselves a bolt in
oops we've got the trigger string, lift aim.
and that was kind of a nice shot I think. Because the problem is actually
very difficult to see what you're shooting at so I reckon because the
whole machine the headstock is in the way. I reckon this is very much a team effort
and then the ratchet back on, oops still getting used to the
machine and sort of fumbling it a little bit, winding it up. Perfect.
But it wouldn't surprise me at all
if the Romans had angle gauges of some kind on their machines; somebody will know out there.
and that it would tell them exactly what range that they were doing.
Lift. Aim.
That looked like a good one, so again just putting the stand up underneath because that way it allows
you to get all of your distances very easily, but it keeps working height at a good height.
So like I say the stand was a little different on the originals, but I had to knock this up
pretty quickly. So trigger back down, bar back in, rope's untangled, ratchet back on,
everything's working fine now, wind it up.
lift and oh again I couldn't quite see, but it felt right. Stand back into position, ratchet off,
pulled open trigger, fingers down, trigger bar underneath, rope's untangled, ratchet back in.
far back in
This is the last of them for now I think and the bolt back in,
remembered the string this time. Lift and shoot. Over.
Got the guy behind I guess. Right that's it for now I think and here we are at the end of film
number one with the catapulta and it won't be the last I promise you that, because we need
to find out how I can make it more powerful, what problems I get on the way, will it explode? it's
always a chance with that much energy, how far would it shoot, what will it shoot through? All
these are questions that we're gonna go and find out, we'll find out because we need to find out.
Will it ever do the 600 meters that the Romans thought that these machines could do? Well we
could find that out too. Personally I doubt it will happen because my experience of these things
is that you have to put so much time and expertise into learning one thing to get the best out of it,
I haven't got time for that, but will I have fun trying. Will it be a lot more powerful than it
is now? Yeah that is for sure. So one last shot and we'll see you again I hope you've enjoyed it
see you again guys
nice one to end