[Spaceships] It seems that TL7 Chemical Rocket's acceleration is an overspec.

[Rupert]

Originally Posted by Pectus Solentis

When I played Kerbal Space Program, only 1.2G-1.6G was sufficient to escape Kerbin. And I know that TWR of real-world Saturn V is 1.15G.

The initial acceleration might have been that low, but maximum acceleration for the Saturn V's first stage was about 3.5G. What's more, the system was designed to not have too high an acceleration - both the first and second stages cut fuel to the centre rocket well before they did to the outer ones to keep acceleration within set amounts.

Also, the F-1 rocket used in the first stage has a thrust/weight ratio of 94-to-1 on its own, so Spaceships is actually being conservative - an F-1 weighing 8.4 tons in a ship weighing 168 tons (twenty times as much) would have an initial acceleration of 4.7G.

Likewise, the 2nd stage J-2 had a 73-to-1 thrust/weight ratio.

Russian launch rockets have thrust/weight ratio of anywhere from 75:1 up to at least 137:1.

I'm not sure how generous (or not) Spaceships is with delta-vee, but it's conservative with rocket engine accelerations.

As for the TL9 HDEM rocket - it trades raw thrust for efficiency. I doubt anyone would think it very unreasonable for you to decide that chemical and HDEM rockets can use the High Thrust option available to most other reaction engines (x2 acceleration, x1/2 delta-vee per tank).

Now, if you want numbers that don't make much sense, consider jet engines. Being generous a modern jet manages a thrust/weight ratio of 5:1, or 8:1 with afterburning, which should give 0.25G per system (0.4G per system with afterburner). Also, they should burn an entire system of fuel per quarter hour of normal thrust and every 7.5 minutes on afterburner.