This part is from Sirens!
cost:
8000
mass:
75
category:
Engine
TechRequired:
advScienceTech
engine_data:
Forward
{"isp"=>{"vac"=>100000.0}, "propellant_ratios"=>{"HeavyFuelOil"=>1.0}, "max_thrust"=>100.0}
resources:
Steam
250.0
HeavyFuelOil
250.0