Here’s an Excel spreadsheet with all the design bits I gleaned from “Footfall,” covering the Message Bearer, the digit ships, the Michael, stovepipes and Shuttles. Not a lot of specifics, and a fair number of contradictions. The genius of it, though, is that basically every description of a ship comes through the eyes or words of a character… which means that they could be wrong, and certainly cannot be assumed to be accurate.
One contradiction: on page 44 (of my first-edition hardback, your mileage may vary), the President says that the Message Bearer is “well over a mile in length,” but on page 46, the exact same speech quotes “perhaps a mile in length.”
One might question why I’m bothering with all this. After all, “Footfall” will be only a fraction of the chapter on “Nuclear Pulse in Popular Culture,” which will be one of the shorter chapters. And the Michael suffers from not having any mathematical basis, nor a good idea of just what it looks like (while the Messiah from “Deep Impact” is shown in detail, and the Orion from “Orion Shall Rise” was sketched for me by the author, Poul Anderson). But here’s the thing: I am, at the core, a design engineer. Sadly, I don’t get paid to do design engineering these days – even what I *was* paid to be a design engineer, I rarely got to actually do it. Paperwork. Accounting. Corporate rubbish. Feh. So… here we have something of a design challenge: a nuclear pulse propelled space battleship of extraordinary size and power. There’s no such thing as an aerospace design engineer who wouldn’t give his left arm for the chance to design a space battleship. The vague description of the Michael simply forms the design limits.
Of course, if Niven and/or Pournelle were to pop up with some more detailed specs or sketches, that would be great. Barring that, I’ll do the best I can with what I’ve got, and will post progress from time to time.