Design and Technology KS2: How to create a working drawbridge

LAUREN:'Today's Dengineers are brothers Alec and William from Inverness.'

ALEC:We need help from the Dengineers because we live in the Scottish Highlands and where we live on a farm there's not much to do.

JOE:Look at the size of this mound. I don't think we've ever built a den on a mound before Sege.

SEGE:Perfect place, most castles are built on high ground. Well boys, tell me a bit about this castle

SEGE:Is it going to have turrets?

ALEC:Yeah, it will have turrets.

SEGE:OK and how many turrets? Two maybe?

ALEC:Yeah. I think that's a really good idea.

SEGE:I think the castle should have a drawbridge. What about that?

ALEC:Definitely.

LAUREN:'Sege has designed a Scottish castle-inspired den. 'Complete with its own turrets and a drawbridge.'

JOE:'On the inside the centrepiece will be two regal thrones 'that will fill the room with colour. 'A display cabinet will show off Alec and William's very own crowns.'

LAUREN:'And there'll also be plenty of room 'for the boys to store their beloved Scottish history books 'as well as a table for them to play chess on.

LAUREN:'It's day two and the Dengineers are quick off the mark in Inverness.'

JOE:'Sege, how is it going?'

SEGE:Really, really well Joe but it's a long way from finished. 'Today's a very, very big day.' We've got the electrics to do, we've still got a lot of painting to do and the big thing, and I think it's a first for the Dengineers, 'is we've got a big, heavy drawbridge to go in.'

JOE:Wow, that's exciting but terrifying.

JOE:'The first big job of the day is to get this beast installed.'

SEGE:'Do you know what this is boys?'

ALEC:'No.'

SEGE:Well, it's a drawbridge.

ALEC:Oh! Cool.

SEGE:Every castle's got to have a drawbridge hasn't it? How brilliant will that be?

ALEC:Amazing.

WILLIAM:Yeah.

WORKER:-How are you looking at the bottom there Greg?

JOE:'As the team try to put the drawbridge into place 'they run into their first draw-back.'

SEGE:Tell me what the problem is.

GREG:It doesn't fit.

LAUREN:'The mechanism to operate the drawbridge 'is too long to fit into the gap 'but, with a bit of alteration, 'it's not long before the Dengineers team figure out a solution.'

JOE:Talk me through this drawbridge. How does it actually work?

SEGE:You know you see a roll of shutter doors on shops don't you?

JOE:That roll up.

SEGE:Yep that roll up on a barrel and the chain's rolling the shutters up vertically you see.

JOE:Oh wow, you can't see that bit normally–

SEGE:No.

JOE:'cause you can just see the blinds.

SEGE:Exactly, so what we've done, is we've done exactly the same thing. So the pieces of string on here represent the chain. So if I turn the model around–

JOE:Yeah.

SEGE:You can see I've put this bolt in here and what the bolt does is the bolt acts as the barrel.

JOE:And that pulls the door up?

SEGE:And it does, there you go.

LAUREN:'Sege's feature drawbridge works by using a chain and barrel mechanism. 'To make things move, the barrel, 'which is operated by an electric motor at the back of the drawbridge, 'will roll round, unwinding the chains to open it 'and the barrel rolls round in the other direction, 'pulling the chains in, to close the drawbridge.'