THE BOOSTER ROCKET AND TB3 HEAT SHIELDS BY AMY AND JON

Blog readers Amy and Jon have sent in this great bloglet:

Following up your recent article comparing the Sword Booster Rocket engine with the JR21 Thunderbird 3 Heat Shield we thought we'd try to help out, so here's a few statistics with some attached pics.

We'll compare the Sword Booster with the JR TB3 and also the Heat Shield from what we assume was the Lincon International kit of TB3 (we can only assume it's from the Lincon kit as the heat shield is all we've got ! It's been in a box of spare parts since the sixties, but we assume it's from the Lincon kit as it's approx. 1/3 bigger than the JR toy, which seems right for the overall size of the Lincon - about 30 cms. - to the JR - about 20 cms.).

It seems unlikely that JR and Lincon would share each others moulds but we thought we'd throw it in for completeness ! We've also noted the number of "Ribs" or "Fins" that go around each piece. So-

JR TB3 heat shield - 3.75 cms. long with 16 ribs

Booster engine - 6.5 cms. long with 12 ribs

Lincon TB3 heat Shield - 6.5 cms. long with 18 ribs

So there doesn't seem to be much correlation - even if the Sword part was "tooled up " in scale, it could be expected to have the same number of ribs. However ...

A famous part of the TB3 design is the the tiny "flair-in" at the base of the heat shield where the ribs bend back on themselves at around 90 degrees to give an "tucked in" effect (Difficult to put into words, but just look at the base of the heat shield - they are coloured yellow on the JR TB3 ).

Now if you look closely at the pic showing the rear of the Booster engine - there it is - the exact same "tapering in" effect which is distinctive of the TB3 heat shield.

So there we are - that's our evidence - for and against - what does anyone else think ?

Fab stuff Amy and Jon! Thanks ever so much for sharing this! Woodsy