A Design for Engines

Hello, i’m a programmer and amateur game designer, i study the subject of game design and balance with a professional interest. I’m also currently clocked in at 101 hours on sunless skies, and 403 on sunless sea. Not that such credentials necessarily mean anything, but i’d like to communicate that i care, and i’ve thought pretty hard about the following essay

I notice that sunless skies lacks an engine slot in our trains, and really lacks much way to influence the speed of your train. This is something many community members have raised as an issue, and i’m hoping that FBG has some plans to do something with it eventually. But i’m here to throw my hat in the ring
I’d like to put forth a complex, well thought out idea plan for adding Engines to sunless skies. Specifically six engines, divided into two tiers of sidegrades, creating a meaningful choice for the player, and each offering a substantial alteration to how the game plays.

To start with, add an engine slot. One (and only one) for every train. Add a default engine which goes there as a placeholder, which is neutral in all respects.

Now with thinking of engines for this game, one must first look at the variables we have to work with. I see the following things an engine could influence:

  • Top speed: The maximum speed you can attain.[/li][li]Acceleration: How quickly you build up towards top speed. At normal acceleration, you should reach top speed in about 4-5 seconds[/li][li]Heat Capacity: The size of the heat bar. the total amount of heat that can be stored before bad things happen. This is mostly used for powering weapons[/li][li]Manoeuvring: The power of the frontside thrusters. Affects how well you can turn on the spot. This is very important for aiming your guns at the enemy[/li][li]Strafing: The amount of &quotstrafing steam&quot available to the strafe function. More allows more strafing bursts before you have to recharge it. Very important for dodging gunfire and obstacles[/li][li]Fuel Efficiency: A divisor on fuel usage per second 200% fuel efficiency would halve fuel usage[/li][li]Power: How well the engine can cope with heavy trains.

Yes, i’d also add (really, restore) a mass variable. A measure of how heavy the train is, determined by a combination of its base type, how full the cargo hold is, and the weight of equipment in it. Large guns and armor plating would be the heaviest equipment pieces. The base train chassis would be the largest contributor to weight, being responsible for about 60% of it. But the other factors can be significant too

I’d implement this in such a way that, if the engine power is below the mass of the train, it suffers penalties to speed, acceleration and manouvreinging. If the power is greater or equal to the mass, then nothing happens (no gain from putting an overpowered engine into a small train).
This could be a simple tiered approach. light, medium, heavy, superheavy. Any train crossing a threshold behaves about the same as anything else in its weight class
By default, without any bonuses or penalties, an engine of normal power can capably run a fully equipped Medium weight train. Or a stripped down large train, (with no armor, light weapons, and <50% cargo hold)

With all of that in mind, we next ask, what kinds of trains are there, and what do they look for in an engine? I see three main archetypes:

A train focused on making money. Mostly by hauling large quantities of goods between ports, and maximising the use of the prospect/bargain system. A cargo train may try to ignore enemies and obstacles that would get in the way of making money, they want to get to the next port as fast and efficiently as possible, they will probably be travelling straight, pre-planned paths along known and well travelled routes. Cargo trains tend to be large and heavy.

Important stats: 
  • Top speed[/li][li] Fuel efficiency[/li][li] Power
Weak points: 
  • Manouvring[/li][li] Strafing[/li][li] Acceleration
Example: Pellinore

A train focused on fighting sky beasts and other trains. Will fight as much as possible, and have quite a lot of mass from heavy armour and armaments. In a fight, they need to be manouvreable to bring their guns to bear on the enemy, have lots of heat capacity to outlast them, and have enough acceleration to quickly catch escaping foes. Combat ships are typically subpar in top speed, they rely on their superior acceleration to catch up and cut off fleeing enemies, either gunning them down or ramming them into asteroids before their speed can build.
Combat ships are expected to perform, not be cheap. No expense is spared to be the best, hence they have penalties to fuel efficiency

Important stats:

[ul][li] Power[/li][li] Acceleration[/li][li] Heat capacity[/li][li] Manouvring[/li][li]Strafing
Weak Points:

  • Top speed[/li][li] Fuel efficiency
Example: Bedivere

An exploration train focuses on filling out the map, flitting around doing quests, and seeing the world. They will do lots of tight steering around ports and points of interest, dodging various obstacles. They don’t need to fight or carry much, and so will probably be fairly light.

Important stats:
  • Acceleration[/li][li] Strafing[/li][li] Top speed
Weak Points:
  • Power[/li][li] Heat capacity
Example: Parsival

So with that in mind, the first tier of engines. All of these would be, overall, straight upgrades to the baseline engine, but sidegrades to each other. Choose your specialty. Any engine could be placed in any train, not limited to the archetype. All stats will be given relative to the baseline that we currently have. Names are of course just an example, and up for changing. As are numbers, just a rough outline of functionality

The Sparrow:
A lightweight engine for small scout and courier ships. Extremely nimble, well rounded and good in many ways. But it lacks power, and won’t work very well in a large train. Very good for exploring ports and ruins, flitting around tight spaces.

  • Top speed: +30%[/li][li] Acceleration: +30%[/li][li] Strafing: +50%[/li][li] Manoeuvring: +20%[/li][li] Fuel efficiency: +20%[/li][li] Power: -20% (kinda weak, slightly struggles to run even a medium train)

The Turtle:[/b]
A reliable workhorse of an engine, designed for long haul journeys under heavy load. Extremely slow to accelerate, may take 20-30 seconds to reach top speed, so it punishes stopping or getting distracted. But it can make the best time of all if you stay focused. Every possible corner is cut to make it run on minimal fuel and save pennies. A true engine for misers and merchants.

  • Top speed: +60%[/li][li] Power: +100%[/li][li] Fuel efficiency: +40%[/li][li] Acceleration: -80% (Very slow speed buildup)[/li][li] Heat capacity: -30%[/li][li]Manouvring: -20%

The Lion:
A ferocious animal of an engine, designed for cruisers, destroyers, and similar mid-heavy combat ships. Military grade hardware throughout guarantees supreme performance, no expense is spared to ensure it outperforms the enemy. High acceleration allows it to make rapid forward &quotpouncing&quot movements, making it easy to chase down a fleeing foe before they can build up their speed. Powerful manouvring thrusters allow rapid turns in combat to aim the guns, and a high heat capacity ensures you’ll be the last to overheat.

[ul][li] Top Speed: +10% (only a small improvement over baseline)[/li][li] Acceleration: +100%[/li][li] Power: +60% [/li][li] Manoeuvring: +60%[/li][li] Heat Capacity: +80%[/li][li] Fuel efficiency: -30% (it’s expensive to maintain)[/li][/ul] -30% efficiency translates into using ~40% more fuel (1 / 0.7)

Now, not everyone’s playstyle fits neatly into one archetype. That’s why I’d also add the Second tier of engines. Another set of three, but instead of one specialty each, this time each engine takes TWO archetypes to specialise in, making it a hybrid that’s good at both. (but bad at the third)
This time the names are those of deities and mythological figures, to signify the increase in power.

Note that a lot of the things that would be negatives on these engines are simply left unchanged. Even in the parts they suck at, they’re ususally still at least as good as the baseline

The Atlas: (Cargo + Combat)
The biggest, mightiest engine around. Designed to drive tens of thousands of tons of metal through the cold wilderness. The atlas fits best on massive, heavily armoured ships with colossal cargo holds. A suitable engine to drive dreadnoughts and battleships, but also tankers and large scale haulers. Though it lacks manouvreability, the massive heat capacity allows it to serve as gun platform effectively, and the high speed allows it to cruise to ports and battles as needed. (It has no modifiers to Strafing and Manoeuvrability. At tier 2, simply being normal is a disadvantage, compared to the other engines which have bonuses to these attributes)

  • Power: +300%, nothing is too heavy[/li][li] Fuel efficiency: +50%[/li][li] Top speed: +80%[/li][li] Heat Capacity: +120%[/li][li] Acceleration: -40% (still slow buildup, but better than turtle)

The Hermes: (Cargo + Exploration)
The fastest engine ever designed. Made for interstellar explorers, Racing trains, and VIP ships carrying light but precious cargo. A ship powered by this sort of engine is a ghost, turning, strafing and jetting away effortlessly. It combines the best parts of exploration and cargo engines, and is aimed at small to medium ships

[ul][li] Top Speed: +120% (highest top speed of any ship)[/li][li] Acceleration: -20% (May take a couple seconds to build up, but far faster than atlast or turtle)[/li][li] Manoeuvring: +50%[/li][li] Strafing: +50%[/li][li] Fuel efficiency: +50%[/li][/ul] This engine has no modifiers to power, it won’t be able to handle a ship above medium weight without penalties. That’s its main weakness

The Ares: (Exploration + Combat)
The most expensive engine designed,a highly classified heart for an engine of destruction. Intended for use in destroyers, battleships, fleet flagships, and VIP military transports. Everything about this engine is twisted towards a single goal of outperforming the enemy in combat. It is unmatched both at effecting, and preventing, quick getaways, as well as providing a reservoir for steam powered weaponry of all kinds. A train running on this engine becomes a graceful, but merciless, angel of death.

[ul][li] Top Speed: +50%[/li][li] Acceleration: +120% (Catch up to any ship attempting to flee)[/li][li] Strafing: +70%[/li][li] Manoeuvring: +70%[/li][li] Heat Capacity: +150%[/li][li] Power: +100%[/li][li] Fuel Efficiency: -50%[/li][/ul] -50% fuel efficiency equals double fuel usage. You will need to use a large part of your hold just on fuel

    [u][b]Possible Concerns:[/b][/u]

Isn’t there an issue with enemies outrunning the player? Wouldn’t lower top speed put them at a disadvantage?
Possibly, but i believe the solution to this isn’t in the engine. Instead, the preferable option would be to implement some kind of snaring weapon. A harpoon, a net launcher, a miniature black hole, etc. Some way to temporarily stop an enemy so a combat train can pounce on them and shred them

Aren’t you using engine/train/locomotive wrong? They mean a different thing!
This is a matter of debate, here’s a thread for that debate http://community.failbettergames.com/topic25689-on-the-subject-of-terminology.aspx?MessageID=216417#post216417
post your thoughts there!

Closing thoughts:
Engines are an important part of a travel based game, but choices are an important part of a game, period. I’d like selection of engine to be a choice, something you regularly reconsider, and perhaps switch out to better suit your current needs. I’d really not like to see a repeat of the situation we had in sunless sea - where the Fulgent Impeller was the best engine by far, and the entire early game was just a race to grind it as fast as possible.
This design has no objective best, only a range of high quality choices that would significantly impact how you play.
edited by Nanako on 2/1/2018

edited by Nanako on 2/1/2018
edited by Nanako on 2/1/2018

I love it. It’s as if you read my mind.

Nitpick though to prevent confusion while reading: The trains themselves are engines. The thing that powers them is called a firebox or boiler.
edited by Flypaste on 2/1/2018
edited by Flypaste on 2/1/2018

[quote=Flypaste]I love it. It’s as if you read my mind.

Nitpick though to prevent confusion while reading: The trains themselves are called engines. The thing that powers them is called a firebox.
edited by Flypaste on 2/1/2018[/quote]

A firebox is just a device for burning coal.
An engine is a device that converts energy (of various kinds, but often heat, kinetic or electrical) into mechanical energy. The trains themselves are called trains, or locomotives, they contain an engine.

The front car of a train is often called the engine because it is the car that contains the engine (and typically little else). And the trains in sunless skies are designed to resemble that front car, for the most part. However our vehicles in sunless skies - despite the resemblance to an engine car, are fully self contained vehicles with an engine, crew compartments, a cargo hold etc., and so engine is not a correct word for them

I think much of the terminology in the game is technically incorrect, this is a complex subject that probably deserves its own thread.
For the purpose of this thread, an engine is a device installed in some kind of vessel, which does the work to make it move
edited by Nanako on 2/1/2018

Since you’ve brought up terminology:

  1. Sunless Skies has no trains, and I don’t see any signs it ever will. The entire essence of a train is that it is made up of cars in train with one another. A single car is simply a car, even if it’s in motion.

  2. There is a significant theoretical barrier to having an engine slot: unlike a car, or even a diesel locomotive, a steam locomotive is very little more than an engine on wheels. The bulk of its mass is the steam boiler, with a firebox, piston assembly, and a few extra pipes added in. If you remove the engine from the locomotive, all you’re left with is a few wheels and a small platform to stand on. Now, the fact that the locomotives out here can carry cargo and hold more than two persons means that we’re operating on somewhat different tendencies, but the art is still clearly a mounted boiler with a few extras. Changing engines, therefore, means acquiring an entirely new locomotive. You might save a few parts from the old one to weld on (which is what happens with those slots that currently exist), but the engine assembly is the sine qua non of a steam locomotive; without it, it ceases to exist.

  3. An engine slot is also a potential source of confusion. As you yourself have pointed out, the locomotive is generally referred to as the engine the world over. Using a word for a part that is usually taken to mean the whole is not a route to clarity. Yes, most people will either figure out your meaning or shrug and ignore it, but adding an avoidable bump in understanding is probably not too high on the priority llst. It’s also going to annoy train aficionados (e.g. my sons) whom you would otherwise be hoping to attract.

2. There is a significant theoretical barrier to having an engine slot: unlike a car, or even a diesel locomotive, a steam locomotive is very little more than an engine on wheels. [/quote]

Simple answer then, only allow swapping out the engine at a central port, with a yard intended for such things, assume the process is rather involved, but not impossible. For such a drastic change in functionality, having to stop over at new winchester for a couple of ingame days seems perfectly reasonable

As for terminology debate, let’s take this outside :^)
edited by Nanako on 2/1/2018

At which point you have demoted Spatchcock and Bedivere and all their kin from locomotive models to chassis. You don’t so much buy a locomotive as you do build one out of components.

This means also that you will need more art resources and some new coding. The engine is, after all, 3/4 or more of the visible locomotive. Players would be understandably upset if you replaced the Sparrow on your rusty ol’ Spatchcock with a spiffy new Hermes, and the visible engine were precisely the same. To avoid this you would have to accommodate changes in both chassis and engine, either coding for a composite image that glues, e.g., a Spatchcock cab onto a Sparrow boiler, or manually creating such images for each possible combination (which is a lot of hours for someone).

In short, I think you’ve got an interesting system, but the wrong implementation. What this system needs is not to be put in as an Engine slot, but to be the engine cars themselves: the Spatchcocks and the Pellinores and so forth. Six locomotive modules on your pattern would provide a sensible solution to most captains’ needs. Not the only solution, of course, but a sound one.

At which point you have demoted Spatchcock and Bedivere and all their kin from locomotive models to chassis. You don’t so much buy a locomotive as you do build one out of components.[/quote]
I don’t see any reason to believe they were ever anything else. There is afaik no variation in most of the above stats for any trains.

I disagree, we don’t need that nor would they be upset. The engine is an internal device that slots into the long part of the chassis.
(it probably needs a lot of un/re riveting and welding to swap out, but the external plating covers it either way). Visual engines would be nice, but i don’t agree that it’s a necessary or even important part of this design. Merely a cherry on top. One that would require a dubious amount of art effort

Sunless sea never had visible ship parts and nobody complained. Nothing stops you from slotting the Fulgent Impeller into a Stymphalos Steam launch, even though that engine would be far too large (The stymphalos is described as barely larger than a dining table)

There’s been no complaints about the lack of visuals for mining/canning systems, and no reason to expect there ever will be. I’d only expect armour plating and guns to have visual assets, engines can be nonvisual. All the external parts of the engine - the thrusters, steam vents, etc, can remain on the train when an engine is swapped out, the engine is simply the heart that pumps steam through those orifices.

Think of swapping engines like a heart transplant on a human.

Locking such stats to the engine just denies customiseability to the end users. I’m not in favour of that.
While the weight system would softly restrict what engines can be used where, it offers a little wiggle room
edited by Nanako on 2/2/2018
edited by Nanako on 2/2/2018

… And I loved it. Just came here to say that this is the exact kind of system that I’d enjoy.
edited by A Parliament of Hounds on 2/2/2018

I think we have a misapprehension here. The engine of a steam locomotive is not an internal thing, as it is on a car or a modern train. It sits exposed; indeed, it comprises everything between the cab and the cow catcher. The long cylinder that makes up most of a locomotive is the steam boiler, the heart of the engine. To the front of that sits the smokebox. Steam circulates through exposed pipes running along its sides. The cylinder which houses the pistons sits (usually) at the front, which is then attached through visible connecting rods to the drive wheels. The only part of the engine you can’t see from the platform is the firebox, which is partly contained in the cab. That is why I was saying that if you take away the engine, you no longer have a locomotive; you only have the cab and a set of wheels.

One could always put a casing of some sort around this assembly, as very late steam engines (like their diesel and electric descendants) did in fact have. However, once you did that, it would no longer look like the Victorian-era steam locomotive we’re expecting, and the Victorian industrial atmosphere would essentially be lost. Thus, not showing the engine is probably a non-starter.

i don’t wanna paste the same thing twice, this post is my answer: http://community.failbettergames.com/topic25689-on-the-subject-of-terminology.aspx?MessageID=216442#post216442

But i’ll paste my summary for terseness

edited by Nanako on 2/2/2018

… And I loved it. Just came here to say that this is the exact kind of system that I’d enjoy.
edited by A Parliament of Hounds on 2/2/2018[/quote]

Glad to hear it <3 We do seem to be getting a little sidetracked on hard-science discussion of how steam engines work, but there is a relevant question in there:

How important to you would it be, that these engines have a graphical representation?
Siankan believes it to be utterly essential

I believe it would be a pleasant addition, but unnecessary and not worth the effort to do so.
Would you be upset if there was no visual change?

I see no need for a graphical implimentation as long as specific terminology is used to clarify that the part that makes the locomotive move is only a small part of its interior space. In my mind the “boiler” part of the train is the crew quarters & hold space, with the boiler actually taking up the cab section.