[Spaceships] Black powder Rockets?

[Agemegos]

Originally Posted by Marasmusine

When scouring for information, I've seen thrust-to-weight ratios of 3:1, 4:1 or 5:1 when discussing the minimum thrust for competitions of model rockets

Bear in mind that in GURPS Spaceships' terms the model rocket motors you buy consist of a engine and some fuel tanks, not just an engine. Listed thrust-to-weight ratios in the spec will be for the fully-fuelled motor at ignition, not for the almost-empty motor at flameout.