From The Art of Ralph McQuarrie
Organic Machine concept sketch.
They were talking about a great powerful brain in this huge machine which was guided by organic matter. I gave the machine arms and eyeballs on stalks. You can see a man working on a console controlling it in the foreground to establish scale.
No clue how this fits into the story....maybe Titans tech?
What struck me a moment ago (duh) is why "Titans" was selected as the name... since it was the Titan
who brought fire to mankind. I'd gotten so rusty on my Greek Mythology that I had to have a dose of the metaphorical oil can to get the gears turning on that.