(''DOCTOR WHO'' THEME) As regards allocations in the BBC, people were divided into categories - people who were artistic, engineers, people who enjoyed model filming and people who enjoyed electronics.
My bent was the artistic side of it.
Then ''The Green Death'' came up, and Ron Oates decided I was gonna make the maggots, which was a huge part of ''The Green Death''.
And Richard Conway, who was fresh from ''Thunderbirds'' and the film industry in the '70s, was also an engineer, so he had quite an input on the engineering side with the headphones from the brainwashing sequence.
(MUMBLES WEARILY) There were various types.
We did use hand puppets when the mouths didn't work, so you could get your arm into the maggot and move it.
But for close-ups, they had to be on rods.
To my recollection, they were plastic replica weasel skulls, which probably came from the Natural History Museum.
We thought about terrier skulls, but they were far too big.
The maggot would have to be enormous.
The test of how well you've done is when you present what you've made for the first time.
And I was amazed at how the giant maggot puppets went down.
We thought they looked quite good, but the cast were terrified of them, basically, particularly the females, so we'd obviously achieved our goal.
You couldn't obviously have dozens of puppet maggots, so we elected to go for ordinary domestic fishing maggots.
Obviously, we filmed that on a high-speed camera with suitable lighting.
One thing about maggots - it's not the most pleasant element to use.
To start your day with your hand full of wriggling maggots, you could freak out, but we were so into what we were doing.
You position one carefully and run the rest around.
We used lots of hand cleaner - Swarfega - for the slime, both on the giant puppet maggots and these others, and various food thickening agents were huge pools of slime.
(WHOOSHING) Parts of Metebelis Three were filmed in South Wales.
I made these giant papier mâché chicken legs.
They were papier mâché because they had to be really light.
They were about 8ft tall.
Richard and myself had a long pole, swinging them in from either side.
There was snow flying across, so we had a wind machine.
It was probably paper snow.
You can't sprinkle too much of that, so we put smoke through a wind machine and a few snowflakes in, and it looks like a blizzard, but there isn't that much going on.
A lot of blue lighting to give that intense blue light.
One day, some schoolchildren turned up.
Jon was supposed to be hanging from high up.
As usual, he was six inches off the ground, which caused hilarity amongst the schoolkids, but didn't go down too well with Jon, because he was trying to do his best cliff-edge acting.
There's another lovely scene with the tentacle wrapping around Jon.
That was a sprung wire tentacle.
One was a reverse, where they'd sprung it off, reversed the film, and it looked like it was grabbing him.
These are what you call the ''money sh*ts''.
Because it costs a lot to do.
As a model sh*t, you've got to film it elsewhere.
You need high-speed cameras and obviously you've got to build the model so it's an exact replica.
So an awful lot of work.
The sides of the model were probably brittle foam, pre-cut, because it falls away quite nicely at the top.
The explosions are usually just black powder charges with a bit of titanium powder, which generates a lot of blue sparks.
They look big because they're sh*t at high speed.
They're actually quite small explosions.
Basically, it's a plastic-backed material with millions of tiny glass beads in it called front co-axial projection material.
Its main element is that it reflects back 92% of any light projected at it.
It's projected down the axis of the camera, so you can increase the light, and it pulses, and decrease it.
To be spot-on, you project through a 50-50 mirror at 45 degrees to the camera, so the camera's sh**ting at 45 degrees to the light source for front co-axial projection, but you can use just a light strapped to the camera, which we did a lot, mainly for reasons of movement, for flexibility in the movement.
You just have to pulse it to get this wonderful glowing effect.
These days, it would be done in post-production, but we did it for real.
Good grief! Another sequence which I don't think any of us were happy with at the time - or later - was when Jo and the Doctor were in their little cart, running along the mine shaft tunnel.
In the background were maggots on the wall.
In the foreground was a maggot peering over.
The background was in focus, so it looked totally unnatural, but the danger of doing this is this horrendous fringing problem.
You could see the edge of what had been superimposed against the background.
Explosions can be guided if you put it in a steel inverted pyramid.
You can guide it in any direction, and people can get close to it, knowing that no shrapnel will come off it.
You put on peat and cork and various soft elements.
But most of those explosions were extremely visual, so there was a lot of black powder, which gives a great red glow and smoke, and we used a lot of army shell simulators, again contained in these steel sleeves.
It takes a long time to set up, so you've only got one realistic go at it, so it's rehearsed till everyone knows where to be, and we know exactly when to press the buttons, because it's all fired electrically.
It's one the most enjoyable Doctor Who programmes - no, programmes full stop - that I've ever had to work on.
It had all the elements - model filming, physical effects, explosions - which every visual effects guy likes doing.
And I think the elements gelled really well, given the time and conditions we did them in.
I'd do it all again if I could.
Well, this is strange.
30 years after making the maggots, I'm back making another.
All that's changed is that the workshop is being taken apart, as it's been closed down.
Here we are making the giant maggot.
The major difference is the convoluted tubing's plastic rather than canvas, which is, for reasons of accessibility, much better.
I'm just gluing down the foam around the head.
I'm starting with the head because it's the trickiest bit.
It's got a definite shape.
The edges around the jaw are feathered, bent in and glued, so they look like a nice smooth line.
The other major difference between this and the originals is the skull is much bigger.
It's a terrier skull, but it still works fairly well.
Also, you can see the elastic bands where it's been sprung shut.
The tube is split at either end, and then the shape of the head is cut out of the top and bottom, and they're wired onto the skull.
This is the body starting to go on, although it doesn't look like it.
I've got a rough indication of where the joints go.
I'm cutting that with a straight edge so there's no slippage at all.
In the foreground is a latex that we use.
The mouth and head have been sanded and curled in for a smooth finish.
That'll be treated with Copydex and curled over.
Not a bad fit.
At the sides of the head it's actually just sheet latex.
I've cast some sheet latex up, with some pigment in it to hide that join between the upper and lower jaw.
This is the tail section.
Again, these are just pieces of foam trimmed with scissors.
They'll be covered with latex.
And on the top, there's a latex filling.
That will be pushed together as well.
This is being held open at the jaw because inside the foam mouth parts are drying.
I'm putting an extra bit in because the shape isn't right.
On the original, it was much more bulbous.
Just chamfering it so we can feather it.
Just trying to get more definition around the head area, so additional elastic bands.
It's been filled along the back with a mixture of latex and Cabasil, a thickening agent, and I'm just trying to smooth it over so it blends into the foam.
This has actually been sprayed with three coats of latex, with a coarse spray, and then colouring applied, again with a spray, but it's not corrosive or toxic.
I'm putting the cling film on.
The most difficult bit is around the head, where the most movement will be.
I've gone right down the body with cling film, applying more rubber bands, and I'm trying to hold them in position by applying more latex.
This is getting near the finished maggot.
The cling film will keep the colour intact when you put slime on the top.
And there you go.
The body flexes well.
It's got a nice fluid movement.
Definitely ready to go fishing!