All The Best Wenches Have One

Inspiration obvious.
If you haven’t already, go read
Girl Genius.

wrenchhammer: the largest size of wrench, suitable for leaning on, requiring a backsling to carry, and used for such tasks as unbolting the lids of reactor cores, dogging down the doors of pressure chambers, or tightening the bolts securing the drive chain of an elevator that runs all the way through the planet.

Its soubriquet comes from the blunt and spiked faces added on either side of the wrench socket, suiting it admirably to belaboring particularly heavy machinery or doing the needful should one encounter any of the various beasties lurking in the deep tunnels of the Eliéran crust.

Rumors of a militarized version of the wrenchhammer (the “warwrench”) designed for the Imperial Legions’ combat engineers are just that – rumors, based on rookie pranks and the occasional mock-up hanging on mess walls. Not that the standard model hasn’t cracked a few heads from time to time.

– engineering_jargon.text

Hohmann Transfer Delta-V Approximator

Speaking of handy little Mathcad tools, this one is a generic delta-v approximator for planet-to-planet Hohmann transfers, based on the same mathematics as this Stack Overflow answer:

As mentioned there, it makes various assumptions, including that the bodies’ orbits around their sun are within delta of circular and coplanar (which works reasonably well for Sol), and that you aren’t using low-thrust drives and as such it can get away with treating burns as instantaneous. The further you wander away from these, the more approximate the approximation gets, belike. Caveat calculator!

Anyway, here it is:!90356&authkey=!AAMfSsixhk7pGRI&ithint=file%2cmcdx


Basic Delta-V Worksheet

So, as those who follow my Google+ account will know, I use PTC Mathcad to do the various calculations behind the scenes to reality-check my work, starship designs, orbital parameters, etc., etc. And being the kind and generous soul that I am, I thought I might clean up and share my tools for the benefit of, well, everyone who wants to do this kind of thing.

Here, then, is the first of those cleaned-up sheets – a basic calculator that does the ground-to-orbit-or-escape delta-v calculation, as illustrated by Atomic Rockets here.

Here’s what it looks like (printed as XPS); and here’s the live version for those of you who have PTC Mathcad (requires only the free-for-life Express version).