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Author Topic: Understanding thrust/velocity? Adding engines can reduce max velocity?  (Read 1063 times)


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On some of my builds adding engines can reduce max velocity at a certain point despite the mass of the engine being negligible compared to overall mass, thrust does increase however.

Say I design a ship, add most of the parts, and then start filling up the empty spaces with mass I reach a point where I need to add engines to compensate for the added mass but the results are mixed and incomprehensible to my admittedly simple mind.

I searched the forum but couldn't really find any answers, I have the right amount of engineers and I do know that I can just boost the max velocity via adding more engineers but I want to understand what is going on here.

Is there anyone that can help me out and explain what is going on?


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This can happen if your engineers are below 130% with the added engine. Try this:

Add lot of engines to your ship and get your engineers to 130%. Then remove the engine blocks one by one, and the velocity will reduce with every removed engine block.


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Also it depends on what material you build your engines out of. While all engines have the same thrust and max speed, they can weigh different amounts. Adding iron engines gives less of a benefit than titanium ones. You can especially see this with thrusters.


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Agree with the above. Main engines control max speed. Engines benefits can add up from 3 things.

Volume = how much space it takes up which controls how much total thrust it provides.
Material = how much it weighs (mass). Lighter material increases your thrust per weight ratio which increases acceleration.

Engineers = at 100% you function as expected. You can add surplus of engineers for up 130% benefit. (You can add twice as many engineers that you need, but the benefit stops at 130%).

This is important to keep in mind for when you add engines. Let's say you have a super huge engine that gives 500 units of thrust. Your at %100 for engineers. You add a little bitty engine, it gives 1 unit of thrust. You entire efficiency goes to 99% because you forgot to hire the extra engineer.

99% of 500 is 495. Plus your little engine running  at 99% so another .9 thrust.

Your new Total thrust is 495.9, that is 4.1 less than what you had even though you added an engine. It's not quite that simple due to ratio of engineers per volume of engine, but you get the general idea behind it.

Now I don't remember if top speed is linked to volume of the engines or the volume and thrust to weight ratio.

(Keep in mind this is somewhat counter intuitive to real life, where currently used forms of thrust - Non-theoretical or sci-fi - in space travel are more functions of surface and not volume.)

Edited for clarification.
« Last Edit: July 12, 2017, 09:19:40 PM by WSY »


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Thanks for the tips, perhaps it is that my engineers dropped below 130% as when I am building I normally have a surplus crew to prevent having to stop half way to hunt for new ones if I build too much. I knew it wasn't from dropping below 100% because you notice that. I probably need to do some testing to see what the issue is.