While updating my steam engine design for a big update to my thread, Optimized Steam Engine Setup, I have found two possible bugs:
1) Boilers can't seem to actually sustain steam output for 2 steam engines at max load. Whether it's in my 60 boiler, 120 engine setup or a basic 1 boiler, 2 engine one, the results are the same - steam very slowly depletes until production starts fluctuating. In my map, I have tested this to take approximately 25 minutes to lose 600 steam in a boiler and 2 engines, which makes for about 1 steam lost every 2.5s. BlakeMW posted more about the technicalities of it in the thread, if the info is needed.
To reproduce this, let the red belt fill up with coal on my map, then flip the power switch. You will see the boilers slowly losing steam, followed by the 2 engines each they're connected to, over roughly a 25 minute period. Additional coal will be needed on the red belt before roughly the 20 minute mark as well (related to second issue in this report). At roughly 25 minutes, production will regularly dip a few MW, for each time engines are out of steam.
(Below confirmed as not a bug)
To reproduce this, let the red belt fill up with coal on my map, then flip the power switch. In roughly 20 minutes, the last couple steam engines will start fluctuating with coal outages. And from comparing their downtime with their uptime, it'd appear that the red belt is able to supply an estimate of 119.5-119.8 steam engines at max load.
As these two issues seem to be related, and are testable and reproducible in the same scenario I have provided below, I have listed both in the same thread, for ease of access. Please let me know if it's more preferable to keep these two in separate threads instead. Thanks for your investigation into this.
Edit: Please refer to BlakeMW's post on Mon Nov 20, 2017 5:59 pm for a save file containing an isolated setup that reproduces the non-1:2 boiler:engine steam ratio bug.