Scratchbuilding Gerry Anderson's Thunderbird 3

Back to INDEX by David Sisson

After the problems of building the very shapely Thunderbirds Two and Four it was a relief to tackle a more simple and straightforward model. Thunderbird Three, like TB1, is a tubular craft that only requires a couple of decent reference photographs to construct an accurate replica. With the continuing popularity of Thunderbirds photographs are easily available and with the simple and repetitive design it was only necessary to draw an outline of half the model.

The craft was represented, on screen, by three different scaled models and their general overall contours are reasonably similar to each other with just a few differences in certain areas. However due to wear and tear and the upgrade and refurbishment for the feature films they all have differing paint schemes and minor detail changes from photo to photo, with the medium sized model having at least four different finish's.

Normally I like to pick a favourite studio model and build an exact copy but with this craft I decided to make a standard shaped version combining what I considered to be the best detailing from the originals. Although my collection of T'birds isn't built to the same scale I decided that with the others being between 20 to 40 inch's this one would need to be towards the bigger end and picked a length of 34 inches, which makes it big but still reasonably easy to handle.

The nosecone was one of the first bits to be tackled, and as I didn't have a lathe to turn it, I had to resort to making the shape in Plasticard. Here the tapering outline of the nosecone was made from two pieces, cut up, and glued together at a 90-degree angle to each other. Then a series of discs were cut up into quarter sections and glued into position to block out the general shape.

The rocket engines were made using the same technique but this time only half the shape was formed. Here the next stage has been reached with epoxy filler being applied between the plastic ribs to fill out the overall shape.

When I was happy with the shapes plaster moulds were made. The nosecone could be done in one moulding and was cast up in fibreglass.
Six copies were needed for the engines - here the parts were just cast in P38 car filler. These halves were paired off and glued together with more filler to seal any gaps.

These were now sanded down to get a perfect join by repeatedly rotating the pieces against abrasive paper. As with the nosecone the parts were initially made slightly bigger as some bulk is lost in the construction process.
As a check the outline of the final shape is cut from cardboard and the parts are sanded down until they can be passed through this template.

To construct the fuselage I simply had to order three sizes of plastic tube from EMA Supplies.

The two wider tubes were cut to the required sizes and assembled on the thinner central tube using 2mm Plasticard disc's with holes in the centre (like giant washers).

The reducing areas were again made by forming the shape using plastic and car filler. Care had to be taken not to damage the surrounding plastic pipe during the sanding process.

Moulding the parts in two halves can lead to problems, when you come to join them together, so I decided to try and mould and cast the main hull in one go.
Here I applied plaster of Paris to the master and used larger pieces of pipe and cardboard to hold the wet plaster in place around the tall construction.
After the plaster had set I could force out the master using the extra length of the central pipe sticking out of the top.
(The pipe on the right contains the plaster mould of the nosecone.)

Casting the model using this one-piece moulding was problematic as it was hard to get a consistent thickness of fibreglass throughout - or more importantly getting the material into the centre of the narrow plaster mould.
I had to resort to swilling the resin from one end to the other and pushing the fibreglass matting into position with long rods. This was one very messy casting process but it did work out rather well in the end. (although there were a few holes in the middle of the final cast that needed filling)

Here the nosecone has been superglued to the main hull and the docking ring added to cover and strengthen the joint.

The whole model is coated in layers of spray filler and rubbed down with wet & dry paper for a smooth finish.

The three engine supports were cut from MDF sheeting. A centre guideline was drawn around the edges and then the sides were sanded to the line to create the aerofoil shape. These parts were coating in resin and sanded further to achieve a smooth tougher surface finish, then they were glued to the main hull.
Two screws were half buried in each support with the protruding heads locating into holes drilled in the hull, epoxy car filler was then applied to the inside of the hull to lock the parts into place.

When it came to the engines I decided to copy the big studio model and have the four retro-rocket tubes instead of just the one large inlet. To do this I drilled out the end and fitted a unit soldered from five brass tubes into place.
This was pushed in level with the surrounding surface and then it was covered in more car filler. After it had all set I sanded the area flat and then used a small hammer to gently tap the filler inside the tubes further down to create the four recess's.

The filler in the central tube was knocked out completely as this is where the arm tubes anchor in place.

The three arm fins were carved from wood and coated in resin, then sanded smooth. Metal pins were inserted into both ends.

(Above) The three rocket exhaust tubes were turned from aluminium and glued into position at the end of the build.

One of the trickiest parts of the construction was getting the three fragile looking arms straight and equally spaced.
The brass tubes were superglued into position and then the arms were fitted. The metal pin in the end was covered in 2-part epoxy glue and pushed inside the brass tube to provide a secure connection, while the pins in the other end slotted into holes in the hull - and thankfully over the many years of handling have not showed any sign of coming apart.

The model was again finished with motorcar cellulose spray paints.

The central cooling fins were cut from Plasticard and painted before being fixed in position. Again a tricky process to keep them straight and equally spaced around the hull.

The blue and yellow lines were added using Letraset flexline tapes, just like the original models.

The three lots of Thunderbird lettering were actually made by cutting the letters from self-adhesive paper labels, which were then over painted. This looked rubbish on TB1 but was fine on this model.

All the 3's were spray-painted on, using plastic templates to cut the shapes from masking tape.

The finished model on display at Bradford, with an original Alan Tracy puppet and preproduction artwork by the late Derek Meddings.

Overall the model is dimensionally perfect but I think the paints are wrong. The orange is too red and the central cooling fin section should be more on the plain grey side instead of the titanium I used. So its needs a revamp at some point in the future.

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