- For more than 25 years, there's been a medieval castle
under construction in France. The builders and designers here
are using plans and techniques that are as historically accurate
to the 13th century as possible. Guédelon Castle is experimental archeology
and a tourist attraction. The techniques rediscovered here, they're now helping with the
reconstruction of Notre Dame Cathedral. But I'm here for one very
specific piece of technology that I'd never heard of, and which to me feels like something out of the anachronistic fiction
of Astérix or the Flintstones. It's called the treadmill crane and it is a real thing from history. Now I'm not an archeologist or a historian so I'm going to let someone tell you
about this place, and about this crane, while I actually go and get some stone and learn to power this thing. - So when we say we're
building a medieval castle, of course we have to be very clear about which period of the
Middle Ages we're interested in. So we've narrowed down
our area of interest to the 13th century. To be even more precise,
when we laid the first stone we said it was the year 1228 and each year we move forward in history. So this year on site, you are in
the year of our lord 1253. So in order to find out what technology
was available at that time, we have a number of different sources. We use illuminated manuscripts,
stained glass windows, financial records. Of course we work with archeologists,
art historians, and castellologists. And so we've got all
that information together in order to decide how the
castle should be built. Sometimes we know how to do it, sometimes these skills
have never been lost, others have been completely lost and we have to then
revive them from scratch. The castle itself will be finished
in about another 10 years. So we're taking about 35 years
in all to finish the castle which is a really long time
compared to the Middle Ages. Because one of the reasons
that we're building this castle is to show the visiting public. So half the time my colleagues
are putting down their tools in order to explain the work we're doing. - So here we are at the single drum winch. - Okay. So that needs to go up there. - Yes.
- Okay. - We can provide the tower with
those rocks, so we can build it. - Okay. - We might say that we're
building a 13th century castle but in terms of health and safety
we're clearly in the 21st century. So you will see anachronisms on site. We have hard hats, steel toe capped shoes,
protective eyewear, masks when we're working with
the sandstone from the quarry. All the scaffolding is heavily reinforced. So obviously we're not trying to discover how many people were killed or
injured in the 13th century. - So take care of your back. - The castle that we're
building here today is the castle that would've belonged to a low ranking local
fairly modest nobleman. This isn't a royal castle. It's essentially being
built as a private home but there will be defensive
elements within the castle. There'll be a portcullis, there'll be murder holes,
arrow loops, crenelated walling. And all of this even though
there's very little chance that the castle would've been attacked
in the middle of the 13th century these features are still in place.
You never know. - There's not any fancy modern pulleys
or anything like that, it's just-- - No no, it just-- - Diameter of this
versus diameter of this. - Yes. It's like if you were making
a effort of five flights of stairs. So if you are walking 10 meters,
it's one meter up. - It's like a giant gear, basically. - So we have a couple
of single drummed cranes and we also have a double
drummed tread wheel winch. And the advantage of that
particular piece of machinery is that it pivots through 360°. So that allows us to hoist
loads up from the quarry and then spin the machinery around and place it exactly where
we need it on the masonry. With the double drum winch we can hoist somewhere in
the region of 500 kilos, that's 1,000lb in weight. With a single drum winch, well, there's one person
working so it's half, 250 kilos roughly. - So I'm going to lift 200 kilos. - With this one.
- All right. - 150, 200.
- Okay. - Safety is obviously paramount
when we're using this machinery. So we have someone who's responsible
for applying the brakes. It means that there's no danger of spinning round like
in a washing machine. We have someone who's at the base,
responsible for charging the cradle. And then one person who is
in charge of the whole operation keeping an eye on how far the
walkers still have to walk. Because of course when
you're in the machine you can't necessarily see. So it's a very carefully managed process. This is a technology that
goes back to Roman times but which is being used in the
13th century in cathedral construction. We know that they were in use because there are a
number of medieval cranes that still exist in the
roof timbers of cathedrals. Canterbury Cathedral, for example,
has a wonderful example of that. - Are you going to be on the brake? Does it have a brake?
- Yes. Look. This is normal brake, you can see here. - Yep, it's just friction on that, that... - There's no evidence of a braking system
on these medieval cranes. For safety reasons we've included one,
so that we can stop it if necessary. Strictly speaking, if all is well,
you just stop walking. - Okay. - Okay just go ahead and watch your head. - All right. And right now this won't move
'cause you're on the brake, so... - You can look at fixed points,
to help you. - Yeah 'cause if I'm looking at this...
- Yeah it will be Disneyland! Are you ready?
- Ready. - Okay. - Just walk?
- Walk. - Oh! Oh wow. And look to the side. If I look ahead...
it gets really confusing. Got to look that way,
got to look that way. Hey, but it's working!
- Yeah, it's working. - Oh you're right about that fixed point.
- Yes. - I looked forward for a bit
and started getting dizzy. I'm just walking up a
steep hill. There is some kind of feedback loop, the faster I walk the faster it turns, then the faster it pushes me back. 'Cause of course I'm moving more. But then I risk bashing my
head into the axle behind me. - So these machines are absolutely necessary
in the construction process. We couldn't build the castle
at the rate we are without them. We hoist somewhere in the region
of three metric tonnes every day. - There we go. - Okay.
- Okay. - And stop! Congratulations for your
first medieval crane! - Thank you. I didn't expect quite the
tourist applause there, thank you very much. - Always.
