Engines
I've completely changed engine design for v5.70. This shares a lot in common with the Newtonian Aurora engine design, although without the real world physics. Different engine platforms no longer exist, so you will no longer research "FAC" and "fighter" engine types. Engines are classed as "Commercial" for maintenance purposes unless they trigger a "Military" flag - more on that later. The elements of engine design are now as follows:
Engine Technology: This is exactly as before. The engine technology names are the same and the amount of engine power per HS of engine for each type is the same.
Fuel Consumption: This is similar in concept to the old Fuel Efficiency, although it is now modified by other factors in engine design. Fuel Consumption is far more important than in the past. The initial consumption rate starts at one litre per Engine Power Hour (which is one point of engine power for one hour). So an engine with 25 power using the base fuel consumption technology would use 25 litres of fuel per hour. Additional technology levels will lower the fuel consumption rate (0.9 litres per EPH, 0.8 litres per EPH, etc.). On the engine design summary an engine is rated in the total number of litres of fuel per hour it consumes and also the amount per Engine Power Hour. The total amount is derived from Engine Power x Fuel Consumption per EPH. So an Engine with 15 power and a Fuel Consumption per EPH of 0.5 would consume 7.5 litres of fuel per hour.
Engine Size: You can now select the size of engine from 1 HS to 50 HS. Larger engines are more fuel efficient so fuel consumption is reduced by 1% for every HS of engine. For example, a 10 HS engine reduces fuel consumption by 10% and a 25 HS engine reduces it by 25%. There is no longer any restriction on the number of engines so you can have twin engined fighters if you wish.
Thermal Reduction: As before, this reduces the thermal signature of engines, which, without thermal reduction, is equal to their power.
Power / Fuel Consumption Modifiers: There are two new tech lines to research, called Max Engine Power Modifier and Min Engine Power Modifier. These establish the range within which you can change engine power from that provided by the base engine technology. Increasing power increases fuel consumption per EPH and decreasing power can provide significant savings in fuel consumption. Power can be increased by up to 300% of normal and decreased to 10% of normal if you have the prerequisite techs. The dropdown on the design window will have options from the minimum possible to the maximum possible in 5% increments. So 40%, 45%, 50%, 55% ...... 180%, 185%, etc. Each engine power modifier percentage is accompanied by a fuel consumption modifier, based on the formula Fuel Consumption Modifier = (4 ^ Engine Power Modifier) / 4.
For example, assume you choose to increase Engine Power to 50% greater than normal. The Fuel Consumption would be (4 ^ 1.5)/4 = 2, so for a power increase of 50%, the fuel consumption per EPH would increase by 100%. Bear in mind that if the engine power has increased by 50% and the fuel consumption per EPH has increased by 100%, then the total fuel consumption per hour for the engine is 3x higher than before. This is shown on the dropdown as "Engine Power +50%. Fuel Consumption per EPH +100%".
Crew Requirement: The crew requirement for engines has been significantly reduced. It is now equal to Engine HS x 2 x SQRT(Power Modifier). So an engine with 5 HS and a 25% increase in power would require a crew of 5 x 2 x SQRT(1.25) = 11.18 (rounded to 11). The old method was simply Engine HS * 5.
Here is the design summary for an engine of 5 HS, using Magneto-plasma Drive technology and Fuel Consumption technology of 0.6 per EPH with a 25% increase in power and no thermal reduction.
Magneto-plasma Drive
Engine Power: 100 Fuel Use Per Hour: 80.61 Litres
Fuel Consumption per Engine Power Hour: 0.806 Litres
Engine Size: 5 HS Engine HTK: 2
Thermal Signature: 100 Exp Chance: 12
Cost: 100 Crew: 11
Materials Required: 25x Duranium 75x Gallicite
Military Engine
Development Cost for Project: 1000RP
Because of the power modifier the fuel consumption per EPH is increased by 41% and due to the size of the engine the fuel consumption per EPH is decreased by 5%. The Fuel Consumption per EPH is calculated as the base racial technology of 0.6 litres per EPH, x0.95 for engine size, x1.4142 for the 25% engine thrust modifier, which equals 0.8061. Fuel use in litres per hour is therefore 100 power x 0.8061 = 80.61 litres.
Now lets look at an engine designed with fuel consumption as a priority. This is an engine of 25 HS, using Magneto-plasma technology, with an 80% decrease in thrust and no thermal reduction.
Commercial Magneto-plasma Drive
Engine Power: 80 Fuel Use Per Hour: 11.88 Litres
Fuel Consumption per Engine Power Hour: 0.148 Litres
Engine Size: 25 HS Engine HTK: 12
Thermal Signature: 80 Exp Chance: 2
Cost: 80 Crew: 22
Materials Required: 20x Duranium 60x Gallicite
Commercial Engine
Development Cost for Project: 800RP
The Fuel Consumption per EPH is calculated as the base racial technology of 0.6 litres per EPH, x0.75 for engine size, x0.3299 for the -80% engine power modifier, which equals 0.148455. Fuel use in litres per hour is therefore 80 power x 0.148455 = 11.8764 litres per hour. So while this engine produces eighty percent of the power of the previous engine, the total fuel consumption is eighty-five percent less (about 82% less in terms of fuel per EPH). However, it is five times larger so the base speed is much lower and you will use a little extra fuel pushing the mass of the engine itself. The result is that a ship with this engine will take longer to get there but it will use a lot less fuel on the journey. Note this is classed as a commercial engine and the one above was classed as military. Any engine that exceeds 50% base engine power or is smaller than 25 HS is classed as military for maintenance purposes.
Changes relating to Fuel
As fuel consumption is now higher than in the past, I have made a number of changes to systems related to fuel.
Gas giants have a 50% chance of Sorium compared to 20% in the past. The minimum accessibility for gas giant Sorium is 0.3.
Fuel Harvesters have been reduced in size and cost by 50%. Their crew requirement has been reduced by 80%
Three new Fuel Storage Systems have been added. They are shown below with the current 1 HS system for comparison. Fuel Storage systems no longer require any crew.
Fuel Storage (1HS): 50,000 litres, 10 BP
Fuel Storage - Large (5 HS), 250,000 litres, 30 BP
Fuel Storage - Very Large (20 HS): 1,000,000 litres, 70 BP
Fuel Storage - Ultra Large (100 HS): 5,000,000 litres, 200 BP
Steve
