better engine efficiency vs size

[alex_brunius]

but that means warships are slower to move around and alot faster in combat than now. which has a much bigger impact on gameplay than all fuel usage considerations.

No it doesn't at all. Warship speeds in combat doesn't have to change at all since that was not part of the equation.

Warship combat speed can be identical to today and only adjust cruising speed downward.

How much slower? Somewhere 50-67% is probably reasonable ( similar to civilian speeds anyways ).

[letsdance (OP)]

total fuel usage..... same
warship speed when it matters..... same
warship speed when it does not matter..... lower

the only other aspect is, that you need more total fuel if you use combat speed more often. but even if someone plays so inefficient that he has double the times at warspeed compared to your standard, he only needs 20 % more total fuel (0.2*3.0 + 0.8*0.8 = 1.22). likewise, if someone plays efficient to half his warspeed time, he saves 10 % fuel. that's not enough to make a real difference.

i don't see how this adds something interesting to the game. it may satisfy our feel for what's "right", but from a gaming point of view it's not doing much, if anything at all?

[Whitecold]

No it doesn't at all. Warship speeds in combat doesn't have to change at all since that was not part of the equation.

Warship combat speed can be identical to today and only adjust cruising speed downward.

How much slower? Somewhere 50-67% is probably reasonable ( similar to civilian speeds anyways ).

Combat speed will get faster. If fuel use for travel is decreased, I will use higher power modifiers, to get higher combat speed. This means all weapons will get less accurate overall, and fighters will get less useful, as they implement what you suggest in a two-stage setup.

[letsdance (OP)]

Combat speed will get faster.

i also think so, but his suggestion is to balance it in a way that combat speed does not get faster.

[Whitecold]

How do you want to do that? Fuel is almost entirely used during travel, not combat. 10% seems way to high, most battles are over in a few hours, compared to months of fuel aboard most of my constructions, plus refueling. Fuel usage is the only thing that forces you to not go too high with the power modifier, so to keep the modifier the same, fuel efficiency at a lower marching speed would have to be the same than it is currently at top speed, resulting in overall lower traveling speeds.
If fuel usage decreases, speed will increase, and this discussion distracts from the much better suggestion to make engine efficiency nonlinear with size, which has a valid point, that there is little point currently in picking a 2HS engine over 2 1HS engines.

[alex_brunius]

How do you want to do that? Fuel is almost entirely used during travel, not combat. 10% seems way to high, most battles are over in a few hours, compared to months of fuel aboard most of my constructions

Depends on role and numbers were only as an example. You can make the difference even bigger so that ships in maximum speed consume say 10 times more fuel, and assume 5% time in combat and then it would look like this:

0.05*10.0 + 0.95*0.53 = 1.00  ( so roughly half fuel consumption at cruising speed ).

FACs, Fighters and system defense forces would probably use max speed closer to 100% of their time for as fast interceptions as possible, ( and only if they totally wipe out the enemy cruise back slow ) so I think they would balance out the use of bigger long range warfleets.

Most my ships don't spend much time patrolling since that is a waste of fuel, they are sitting stationary at a body or outpost.

But I agree with your concern that it is hard to balance with variables that rests primary on playstyle.

Another perhaps even bigger unknown for balancing is if the player is using "inexperienced crew" or not, since that requires all new ships to spend months if not years in training expending fuel in cruise speed mode resulting in much smaller percentage of time in combat.

the much better suggestion to make engine efficiency nonlinear with size, which has a valid point, that there is little point currently in picking a 2HS engine over 2 1HS engines.

Nothing is stopping you from suggesting your own formula or numbers that is more balanced. But as I wrote I don't see how letsdance formula/suggestion of changing the fuel saving from 1% to 3% would impact the choice of a HS 1 or 2 engine a whole lot.

I have been playing around a bit with a formula and think something like this would work good and feel balanced for engine size:

Formula: sqrt(10/HS)

Code: [Select]

HS Consumption
1,0 316%
1,2 289%
1,4 267%
1,6 250%
1,8 236%
2,0 224%
2,2 213%
2,4 204%
2,6 196%
2,8 189%
3,0 183%
3,5 169%
4,0 158%
4,5 149%
5,0 141%
5,5 135%
6,0 129%
7,0 120%
8,0 112%
9,0 105%
10,0 100%
11,0 95%
12,0 91%
13,0 88%
14,0 85%
15,0 82%
16,0 79%
17,0 77%
18,0 75%
19,0 73%
20,0 71%
22,0 67%
24,0 65%
26,0 62%
28,0 60%
30,0 58%
32,0 56%
34,0 54%
36,0 53%
38,0 51%
40,0 50%
45,0 47%
50,0 45%
55,0 43%
60,0 41%
65,0 39%
70,0 38%
75,0 37%
80,0 35%
85,0 34%
90,0 33%
95,0 32%
100,0 32%
Edit: I also like the idea to remove detail from the bigger engines ( who needs HS47 engines indeed?) and add it to smaller where it matters, or add more even bigger engines to strech the scale further, so both those have gone into my example above

[letsdance (OP)]

I don't see how letsdance formula/suggestion of changing the fuel saving from 1% to 3% would impact the choice of a HS 1 or 2 engine a whole lot.

my suggestion has 0 % at HS 1. and i never claimed that it makes a big difference for HS 1 or 2, my focus was on larger engines. but it's very simple and quick to do, and even for small engines an improvement over the current system. and it used a formula resulting in a negative modifyer (like the current system), which may be easier to implement than a table.

your suggested saves list has a consistent scaling over all sizes (which is good) but it makes larger engines much too efficient. we already have the problem, that it's better (more speed and less fuel used) to use a HS 50 instead of a HS 25 engine, even if this increases the total size of your ship by 50 %. with your list this would be the same (for all sizes). you're using about 30 % fuel saved for double engine size. i think it should be a maximum of 20% (which is about the value in my list), less (15%?) would probably be even better. if you redo your list with 15 % fuel saved for doubling size i would prefer that over my own suggestion.

there is another problem, which is that it's often better (faster, less fuel needed, cheaper to research and build) to use multiple lower power engines instead of one higher power engine. the only solution (besides completely changing the system) i find for this is to restrict all ships to one engine each. currently that's not possible because of the maximum engine size. with my suggestion it would be possible. adding this to the initial post.

come to think of it, this could be mitigated by reducing the impact of lower power on fuel usage (especially from x1 to x0.5 the fuel needed goes down too much). which would be a good change in my oppinion and maybe also make those higher techs useful.

[alex_brunius]

we already have the problem, that it's better (more speed and less fuel used) to use a HS 50 instead of a HS 25 engine, even if this increases the total size of your ship by 50 %.

Why is this a problem?

If you spent twice as much minerals, time and industry to build a twice as large engine it is supposed to be better. That the way it supposed to work both in reality and in the game IMHO.

Especially for most civilian ships where engine cost is a vast majority of the entire ship cost.

there is another problem, which is that it's often better (faster, less fuel needed, cheaper to research and build) to use multiple lower power engines instead of one higher power engine. the only solution (besides completely changing the system) i find for this is to restrict all ships to one engine each. currently that's not possible because of the maximum engine size. with my suggestion it would be possible. adding this to the initial post.

Forcing everyone to design one engine per ship would be very very bad. Amount of engines is one of the many wonderful design choices that players have in Aurora ( redundancy, repairability and less risk of crippling explosions of many engines, versus fuel economy of fewer bigger ones ).


It also seems you are contradicting yourself, first the problem is that one big engine is better, then your claiming that it's often better with multiple lower power engines. Which is it??

[NihilRex]

I think that a much better solution is the addition of capability to have multiple engine types per ship.

Your cruiser runs on its high efficiency 2400km\s engine group most of the time, but when combat begins, you turn on a second, high-thrust engine group that adds another XYZkm\s to its' top speed while drinking fuel.

[letsdance (OP)]

It also seems you are contradicting yourself, first the problem is that one big engine is better, then your claiming that it's often better with multiple lower power engines. Which is it??

lower power does not mean smaller engine. i was referring to the x power multiplier. this only matters for ships that are large enough to use multiple HS 50 engines (5.000+ tons, which includes pretty much all commercial ships). maybe it would be better if i started a new thread for this.

we already have the problem, that it's better (more speed and less fuel used) to use a HS 50 instead of a HS 25 engine, even if this increases the total size of your ship by 50 %.

If you spent twice as much minerals, time and industry to build a twice as large engine it is supposed to be better. That the way it supposed to work both in reality and in the game IMHO.

in reality, more speed = more fuel used. in aurora in this case, its more speed = less fuel used. that's a problem in my oppinion, because it's not a real decision. it's something that you should always do. especially for commercial ships, higher costs do not matter if the ship travels equally faster - which is the case usually, while using less fuel.

a good game forces you to take hard decisions. engine design in aurora has so much potential, but currently - unless you're somehow size restricted (fighters, missiles) - the optimum ship design always consists of 50-66 % engine. it's boring.

[JacenHan]

the optimum ship design always consists of 50-66 % engine. it's boring.

Except that that ship is far more likely to explode due to engine damage, as well as being much more expensive and larger than a ship with 25% engines. This is a rather extreme example, with boosted engines. Almost none of my ships, except fighters, have more than 40% engines at the most.

I don't have an opinion one way or the other on efficiency, but wanted to point this out.

[alex_brunius]

a good game forces you to take hard decisions. engine design in aurora has so much potential, but currently - unless you're somehow size restricted (fighters, missiles) - the optimum ship design always consists of 50-66 % engine. it's boring.

Personally I never use 50-66% Engines on anything except survey ships that needs efficiency to last for years. All my warships use a much higher power and less tonnage engines to have more mission tonnage and not wastefull range, it's a player choice not something that is "optimum"...

To compensate I use alot of forward bases and fuel dumps where civilian efficient designs can deliver fuel.

[letsdance (OP)]

Except that that ship is far more likely to explode due to engine damage, as well as being much more expensive and larger than a ship with 25% engines.

the point is, that more engines are NOT more expensive. they are actually cheaper. i just started a new thread for that issue with some examples. read it, and then try to redesign your ships in a way that they use more engines with lower power and same build cost. your ships will be faster and need less fuel. fuel is also a resource.

All my warships use a much higher power and less tonnage engines to have more mission tonnage and not wastefull range, it's a player choice not something that is "optimum"...

you don't use more engines instead of mission tonnage. you use them additionally - or you reduce mission tonnage per ship, which makes them cheaper, and build more ships instead, until you have spent the same amount of resources. you don't use the cheaper engines primarily for range, but for speed. range is just a bonus.

i'm undecided concerning the topic of engine explosion. but i would prefer to take all of this to the other thread here:
http://aurora2.pentarch.org/index.php/topic,7472.0.html

[Jorgen_CAB]

You need to add the fact that bigger engines require more engineering sections (much more) and more crew in percentage to smaller engines, this is especially true on overcharged engines.

So bigger engines is a higher risk and more expensive in material, supply, yard space, crew, wealth, maintenance etc... so it is not just clear cut better. You need to trade something for something else. Fuel is also important of course... I always try to go with two or three engine designs

[Paul M]

I have a saying: "Sounds good in theory and works like spit in practice."  That defines this topic.

Mission space is not infinite, as serveral people have said.  Getting a shipyard that will build a ship is a limiting factor of your ship designs.  It determines the exact maximum hull space you have for the ship you wish to build.  Within that space you need to fit in everything you need for your mission.

The NCN has warships and auxillaries built on the same hull.  The warships use more powerful engines, while the auxillaries use more lower powered engines.  That allows them to be only slightly slower but to burn significantly less fuel, and that is critical for a tanker as it means more fuel bunkerage for the ships of the group.  But they are slower because you can't squeeze in their mission package with sufficient engines to make them both more fuel efficient and faster.

The BIC vessels have speeds ranging from 333 km/s to 560 km/s and use 50 or 25 HS engines depending on how many of which I can fit where.  But first and formost their mission package has to be accomadated in the hull.  I can't arbitrarily add engines to bring the speed up because there is no room available.  I switched over from 2 25 HS engines to a single 50 HS engine to get more fuel efficiency since the BIC colonization groups were the single largest fuel drain I had...and pushing their range up to 24 billion km was a major milestone as that is 2 round trips Earth-Faewald.  That is an in-game significant factor that can't be factored in without knowing the context.

I use comercial engines on some survey ships which fundamentally end up being a small mission module on a fuel tank/engine spar.  Their speed is good because the ship is small and power from the comercial engine is large.  Clearly I could get more power (speed) by using my auxillary engines and use five of them but I can't get that fuel efficiency and for a grav survey ship fuel efficiency is the most critical element as they have to cruise for a long time while surveying.

In the game you inevitably will have a fuel crisis and more so from a conventional start.  But even in that the NCN never fitted their military ships with less than 100% drives.  Velocity in combat is too critical.  But too much space for engines leaves too little for mission components.  Smaller military ships are NOT more efficient then larger ones.  3 Terriers would get trounced by 2 Wounded Knees or a single Tribal.  I would tend to bet on the 3 Londons versus 2 Lake class though as the Londons are optimized for anti-ship work while the Lake is designed for group point defence.  The BIC Heavy Lift groups are faster that then typical Colossus/Bauxite groups as well.  The Heavy Lift groups carry more, carry it further and carry it faster.  But how many engines and hence the speed of the civillian ship is detemine entirely by the space left over after it has its necessary load facilities installed.

Space on a ship is too critical to fool around with, unless you are talking abstractly.  In concrete terms you always have to make choices and doubling hull volume devoted to engine space isn't something worth even considering.  If you can afford the fuel bill it is worth exploring what you consider a safe spot between enhanced performance, increased cost, increased fuel use, and increased risk of explosion in combat.  Engines do explode in combat and can cause a considerable amount of interior damage when they do.  Leaving aside maintenance...which is also a critical component to both battle repairs and also overall operational budget.

You have to design the ship around its mission and everything factors into that design process.  So no there is no magic formula to determine that all ships will use one type of engine, and so many of them.  Min-maxing does not work in reality.  It only works in games when you are dealing with a vastly simplified combat system, against a known enemy, who is constrained to do the same stupid thing all the time.  In a real fluid combat situation there is no one "best" solution to every situation.  You optimize yourself into a corner otherwise.  For missiles, in particular, counter missiles there exists a basic formula that gives you a starting point but that is again because they have a straight forward task.  Ship design is not straight forward as it depends on too many parameters to do simplistic optimizations, which inevitably are only valid when you fulfill the underlying assumptions (and those assumptions are rarely stated).

Min-maxing, and more critically simplistic min-maxing is a straight, hedge lined path to firey damnation.

And yes I need to update my AAR...in game it is 2298 now...gah...