A Shield Won't Save You!

[00:00:00]And loose! Now that is a result.

[00:00:07]Hi, it's Tod from Tod's Workshop and Tod Cutler  here and I am back with our Chinese oxbow, our ancient Chinese siege bow and we're going to start  pimping it to try and get a bit more juice out of it. So, we've started now by replacing the old  80 lbs bow that was at the back, with a 90 lbs.

[00:00:25]And I mean, you can't see it, but I can tell you  that really actually feels even for that 10lbs like quite a lot of an increase. Then we are  looking at the bolts here. And this one's really been driven by the comment section. Somebody made  a really good point, which is range is great, but the thing is if you can smack them really hard  at close distance, that's going to be good, too.

[00:00:45]So, I've got a 325 g bolt. So, that's about  65 g heavier. We're going to see if it's still delivering more energy, more momentum.  So, we're going to try these bolts again, get new speeds for them with the new bow  and that new weight. And then the last thing is these pulleys here. They weigh 90g each.  And we are going to try with a lower tech, lighter weight solution to see if we can make  the thing go faster still. All right. So, what we're going to do now is just go through  the bolts again, shooting them one at a time, getting the new speeds, new momentum off them.  Stabroof jacket. I can't explain it. There's something about this machine that spooks me.  Uh anyway, maybe I'm a coward? Who knows?

[00:01:30]And they're all bending about the same. That's  exactly what we want. Okay. 260 g and.... Loose.

[00:01:49]That had a little shimmy on takeoff. So,  I wonder if it's got that sort of funny misalignment issue again without seeing it in  slow-mo. I can't tell you. Well, very annoyingly, it did go in at a funny angle and it got  caught up by the plywood of the target.

[00:02:04]Hit that and you can see what's happened.  We're going to need ourselves a new 260 g bolt.

[00:02:11]Oh dear. So, we're going for a 220 g bolt now. And  loose! Off. It is lovely though, isn't it? Slight wiggle on it. Slight wiggle on that shaft again.  So, I'm going to have a look at the slow-mo.

[00:02:30]Well, that's annoying. So, what's happening is  as it leaves the bow, it's just going at a slight sideways angle. There's not time to correct at  this distance. It's about 30 m it seems. And it's hitting the target slightly at an angle. And  because of that, it's snapping on impact. And that is really annoying because I got to go and make  some more bolts for this afternoon. Right. Next shot. Hi, I've interrupted this film for another  Tod Cutler related interesting fact. And today, 17th century stiletto. All steel construction  and used by gentlemen to poke other gentlemen.

[00:03:04]Anyway, you'll find this and loads of other pieces  on todcutler.com. Back to the film. 160 g. Loose.

[00:03:22]Okay, that was superb. Right, Not broken. Hurrah. Right, we're going to go back  and look at the speeds. Well, that again, it might not sound very much, but the energy figures really  change it. So, the 260 g bolt was 397 Joules. It's now 438 jewels. 220 gram bolt 390 Joules now 426.  And the 160 gram bolt was 374 Joules, now 405. So that little change has made a massive difference.  But the other thing that we need to note here is that this is a cute little baby of a machine,  right? This is not the full size siege weapon at all. So, we know that Chinese hand bows will go  up to 200 lbs in draw weight or even a bit more.

[00:04:15]We know that the ones that they used in crossbow  stocks will go up to 300 lbs or a little bit more.

[00:04:21]I'm just running these, the biggest bows are  100lbs. So, I could be getting three times the bow weight out of this system if I used traditional  Chinese bows. But also, let's not forget that the whole oxbow concept itself was not small scale  like this. These were much bigger custom made bows for this siege weapon. Who knows what kind  of power that is, but at the moment the powers I'm getting for me, 71 m/s and 400 plus Joules is  just phenomenal. But it's nowhere near the power of a full size siege engine like the ones they had  a thousand or 1500 years ago. But what we do have now is a heavier bolt. So we've got a 325 g bolt  and we're going to see what that does. And Loose!!

[00:05:11]And loose!!! We are not getting the  luck today. So our 325 g bolt 51 m/s 422 Joules. So that is lower, lower in the Joules  and lower in the velocity than our 260g bolt.

[00:05:29]Massive momentum 16.6. So what does that mean?  Well, we could go dividing the line between 260 and 325, but I'm going to say probably around  280, 290 was probably optimum. So, we can try for a heavier bolt there. But, in essence, that's  showed us we don't want to go as heavy as 325. So, anything sub 300 and we'll be maximizing basically  the power. But, it's quite fortunate that that bolt actually was too heavy because that is  another one that's been lost. So, I've lost that, I've broken two. So, unfortunately, it's causing  merry hell with my filming schedule. I am not going to be able to do a distance trial today.  So, I've taken these 90 gram pulleys off now.

[00:06:09]And the reason that I've taken them off  is that I have replaced them with an 11g polished steel ring. Now, this was a suggestion  in the notes actually that made me think again because from the beginning I was adamant that  the best way to turn a rope around a corner is a pulley. The Chinese had them, they knew about  them, they would have used them. lowest friction.

[00:06:29]And that's true, but it doesn't account for the  inertia. So, if you imagine you've got a stick and there's no weight on the end, you can  move that stick quite quickly. If you put a hammerhead on the end of that stick, suddenly it  becomes much harder to move. The bow is the same.

[00:06:44]You put a big weight on the end, it doesn't want  to move so quickly. Put a lighter one on the end; moves faster. However, that's going to be  higher friction. So, it's going to be win some, lose some. So, we got our rings on the  end here. And now instead of pulleys, let's see how they work. I've greased the  string up and I've oiled it.....And Loose!!

[00:07:06]Lovely. So the important  bit is what was the speed?

[00:07:14]57.3 on a 220 g bolt. That is 5 m/s slower  using the rings than the pulleys. And loose!!!

[00:07:28]Lovely. Gave us a speed of 57.7. So 57.7. So that  is 4.5m/s slower than the version with the pulleys on. So that gives us our answer. Pulleys. Well,  seeing as I broke my earlier promise of finding out how far these would go with the 90 lbs bow,  I thought we'd bring the barbarian into it. So, what we have here is a proper planked shield in  limewood, faced in leather, backed in canvas, rawhide rim, steel boss. Then we got an archery  foam mannequin and chain mail underneath.

[00:08:05]Let's see what happens. 220g And Loose!!!

[00:08:19]Yes. Oh, fabulous. That is so very cool indeed.

[00:08:29]So, let's conclude this pimping session. We  swapped out the 80 lbs bow for a 90lbs bow.

[00:08:33]Obviously, that gave us a bit more power, but  it actually gave us quite a lot more power because it increased the speed of the bolts 3 to 4  m/s depending on their weights. And in the case of the 260 g bolt, the heaviest one, that gave about  10% more energy. That's a massive difference.

[00:08:52]And then we looked at swapping the pulleys  out for rings to make it a much simpler, much lighter system. Fundamentally didn't work. It  scrubbed about 4 and a half meters/s off the bolt speed. So, I'm coming back quite firmly to the  Chinese knew about pulleys. They used them. They understood them. They could have fitted them and  they work better. So, I'm very happy with that.

[00:09:13]But I'm glad that I investigated the rings. And  then we come to the heavyweight bolt at 325 grams.

[00:09:18]But that turned out to be too much because  the energy started to fall away again.

[00:09:22]So I didn't get an exact weight, but I'm thinking  under 300 grams. So 290 grams, let's say, would be the optimum. And then we come to this man here.  Well, shield, two layers of maile, one torso, two foot, 60 cm out the back. Now that is a  result. But then don't forget that we have a fantastic website, todsworkshop.com, which is  rammed full of medieval goodies that you will love. And then we got a second channel, todcutler.  Go check that out as well. More niche content.

[00:09:52]But in the meantime, thank you for watching  this pimping session and I'll see you again.