The first choice to make in planning a vessel is to determine if it needs to operate in atmospheric conditions, or even if it might expect to do so. This will determine whether rear-facing engines are required, but STL engines will also require this. We should also decide what sort of ship it is (cargo, war, passenger), as this determines the amount and type of quarters, and dining or entertainment possibilities for crew. Next we should decide how passengers and crew typically board or exit the vessel, where they stay, and what they do onboard. We can also determine the purpose of our ship, such as travel within a solar system or between stars. This will help determine what sort of additional engines it has. Lastly, we should decide the events we’re intending to take place on this vessel so that we can decide what sorts of vulnerabilities it might provide us with and how characters and story might benefit from these; but we can also start with this subject. The best choice is to go with the subject that gives you ideas first, then return to less inspiring areas later.
We may want to decide how long it takes people to move between locations in a ship, but this only matters if our story benefits from it. It’s a moot point in small vessels. In an episodic show like Star Trek, where one ship will be repeatedly used, consistency is crucial. In many episodes, characters from the bridge are ordered to another part of the ship to deal with an emergency and arrive seconds later in TV time. We could conclude that the show just skipped ahead a few minutes, but often, whatever emergency was occurring, like two characters fighting, hasn’t progressed more than a couple seconds. The presumed reason shows do this is so that main characters, i.e. actors, are featured all the time, but it’s not realistic. We accept it, however.
If you’d like to be more realistic, approximate how long it takes to walk or run between all locations on a ship and whether something like an elevator is required. How long does it take to climb or crawl through maintenance corridors like the Jefferies Tubes of Star Trek? Are there stairs or only ladders? We seldom see a stairway except in places like engineering (and even then it’s usually ladders). Why is that? Surely if they can invent warp drive they can still see the value of stairs over ladders if the turbo lifts (i.e. elevators) stop working. Are there no stairs (or underwear) in space?
This section talks about everything we’d want to include inside our spaceship and why.
The internal structure of our ship is often important, unless it’s so small as to have little more than a room or two. Characters need to move between locations such as the bridge, cargo, engine room, and quarters. We don’t write about mundane scenes but active ones where the speed of transit is a factor in how the scene plays out. If it takes five minutes at a full run to reach the spot where aliens have breached the hull, and it will only take two minutes for the aliens to destroy the life support systems located there, we’ve got problems. Taking time to plan out our ship’s structure (to some degree) is helpful for not only understanding such scenarios, but imagining them in the first place. No structure is foolproof, as organizing things to avoid one problem will likely cause another, so thinking about our story needs can help us build a vulnerability into our vessel.
Certain realities exist on many ships, such as living quarters being near dining areas. Crew typically have smaller quarters in poorer locations than passengers, except for captains and officers, who may still not enjoy great privilege. Most vessels will need propulsion located primarily in the rear, an area often reserved for dirty or less desirable conditions such as cargo holds, loading areas for both supplies and sometimes passengers and crew, and machinery to power everything. The bridge or command center is typically forward.
Vessels which travel on water load from lower decks, especially for cargo, so the ship does not become top heavy; cargo acts as ballast and should be lower anyway. Also, loading from above just means having to create buildings and ramps to lift potentially heavy items unnecessarily. In space, this consideration is gone, but a ship designed to enter an atmosphere must still be balanced internally, whether that’s front to back or side to side. In a weightless environment, heavy items could theoretically be anywhere, but artificial gravity is seemingly never lessened in areas with heavy cargo. Regardless, one could presumably float cargo to its location with relative ease.
Consider the purpose of our invented vessel before creating its structure. Passenger, cargo, and war ships will share areas like a bridge, engine room, and crew quarters, but entertainment, storage, and weaponry will all differ in size, quantity, and placement. Ships that are intended to permanently remain in space do not need aerodynamics.
Do We Need to Invent Structure?
In video gaming, a ship’s internal structure is crucial because the gamer will typically guide a character room by room through the ship. It should make sense even if the layout or the purpose of rooms is not explained or apparent to someone who’s busy killing NPCs onscreen. World builders are advised to plan a detailed internal structure so that the graphics team can implement it.
But in books or movies/TV shows, the structure often seems irrelevant. Seldom do we follow a character from a room, down a hallway, and to another room; doing so wastes precious screen time. I’ve seen entire series runs of Star Trek and still had little to no idea where one section of the ship is in relation to another. Even so, if we’d like to be consistent for a ship we’ll use often, decide which deck each major department you’ll mention is on. This avoids indicating that engineering is on deck six in one book and on deck seven in another. We don’t need to be more specific than which deck and whether fore, aft, port, or starboard, if we really don’t want to. Having a sense of difficulty and/or speed of access from various other places on the vessel is more important. If creating internal structure helps us do that, then yes, make decisions.
World builders in visual mediums will need to consider both internal and external ship structure, but authors may largely ignore this. Absent a schematic or picture, readers typically struggle to picture what we intend. This is true of other elements like the layout of a castle, for example. It’s often better to not be overly specific about where each room lies in relation to another but rather focus on how long or difficult it is for characters to traverse locations within a certain time frame that matters to the scene we’re writing. Still, even if we don’t explain the structure, we should have an idea of it if for no other reason than consistency between scenes. We don’t want characters to reach the engine room from the bridge in two minutes in one scene and in ten minutes during another.
There’s a tendency to invent aerodynamic-looking ships used in space where air obviously doesn’t exist. This is wise for two reasons: we expect such a design and are comfortable with it, and more importantly, it leaves open the option for the ship to enter a planet’s atmosphere even if this is rare. Would ship builders make that nearly impossible with a non-aerodynamic exterior? Only if certain the vessel never leaves space. Since we’ve seen everything from aerodynamic ships to the Borg cube from Star Trek, we can get away with anything regarding aerodynamics.
What other considerations are there for the exterior? One is the weaponry location, which determines which directions the vessel can fire in. Warships typically have this forward facing, with some ability to aim to the sides as well. Rear-facing weapons are for defense while fleeing. Some vessels have top or bottom mounted weaponry that can swivel and fire in all directions—except into itself, of course.
We might also consider where a ship can be boarded. Cargo is typically rear-loaded. People can be, too, or enter from the side, bottom, or even top hatches. Entering from the front is unusual. The decision can affect scenes where a ship has landed and a gunfight breaks out while characters are exiting or entering the vessel. The bottom-entrance seems problematic because if the ship crashes on its bottom, or the landing gear gives out, how does anyone get out? An emergency hatch elsewhere would be the answer. There’s always a solution for these problems, so feel free to do as you please.
The other obvious subject for external structure is the engine location, but this is typically rear-facing, especially for any vessel intended for atmospheric conditions. The engine doesn’t have to be in the actual rear, as propeller planes make clear. Even jet engines can be like this. With laser-guided weapons that can easily target an engine, it makes sense to avoid engine locations that are vulnerable in this way.
From the previous section on propulsion, we should remember that there are fictional drives that don’t operate on the principle of rear thrust; such engines could theoretically be located anywhere, preferably deep within a ship. What this means from a practical standpoint in war is that engines for STL travel might be rear-facing and vulnerable to attack, but FTL engines might be better protected and less vulnerable. Destroying those STL engines has a tactical advantage to inhibit maneuvering in the battle but won’t stop the ship from going to warp to escape, for example. But if something volatile powers those FTL engines, then placing them deep in the ship might be unwise.
A ship that uses rotation to create artificial gravity will have this as the dominant feature of its exterior. The outside doesn’t need to be round, however. It just needs to rotate. It’s the inside that will be curved to some degree mostly because people and items will be pushed against those interior walls (that’s the whole point), which act as the floor. Gravity increases the farther you are from the point of rotation. This is why we often see a configuration that looks like a spoke wheel; almost all of the living areas are far from the center.
To add realism to our space adventures, we should consider that all destinations are orbiting something. Moons orbit planets, planets orbit suns, and solar systems orbit their galaxy’s center. If two objects are orbiting the same body, such as planets orbiting the same sun, the closer planet is orbiting faster. This means that the distance between two planets will change. They could be on the same side of the sun, opposite sides, or somewhere between.
This is different than fixed locations on a world’s surface, and as a result, we have considerable leeway when announcing how far apart two places are at a particular moment, and therefore how long the trip will take. Due partly to the considerable time such travel takes, a destination is chosen not because that’s where the target is now, but because that’s where it will be when the ship also gets there.
This sort of thing can cause believable problems for characters. What if they realize a critical event is taking place on another planet in a week, but due to the worlds’ current locations, it will take longer than that to get there? Or maybe they only have enough fuel to reach the destination if the trip is short, but they need to go now and don’t have funds to get more fuel. Now maybe they hatch a plan to earn some money. Such details make stories better than ones where everyone just gets on a ship and goes whatever distance they need without much comment or impact on their situation.
Should we decide how far apart our locations are first and then invent propulsion systems according to our story needs, or invent propulsion systems and then alter how far away locations are based on story needs? The latter seems sensible because locations in space aren’t fixed. If we need two locations closer or farther apart for a story, this needs no explanation. Conversely, it makes little sense to devise propulsion systems to go between certain distances when those will change anyway or you haven’t decided how far the characters need to travel.
The amount of time to travel between different objects in space has so much leeway to it that we don’t need the same sort of consistent precision that terrestrial travel may require. On land, we can fudge our numbers by writing, “Not drawn to scale” on a map. But in space, this isn’t even needed. Nothing is in a fixed place except each planet’s distance to the sun, and even that changes a bit depending on how circular its orbit is. And the technologies are imaginary, unlike the wooden ships from the previous chapter or the actual vehicles or animals from the chapter before that.
If you were hoping for a calculator like those in the previous chapters, there isn’t one because most world builders will get along fine without worrying about this. It also involves a level of mathematics that is admittedly beyond me, and possibly you. And no one can come along and say that it would really take fifty-eight hours, not fifty, to travel between two invented planets in two imaginary solar systems, at a given time of the year (from the starting planet), at warp seven, especially since warp drives don’t exist. This is one area where SF beats fantasy handily.
Engines fall into two basic categories: those designed for space travel and those designed for atmospheric conditions. Both kinds already exist, but it is mostly engines intended for space travel which get mentioned in our work. There appears to be a correlation between how often an engine’s functionality is explained and how fictional it is; the more fictional, the more explanations are given. Writers have as little interest in learning and explaining actual technology as the audience, who typically understands it to some degree. But fictional tech? We’re all ears.
Air Breathing Engines
Engines for atmospheric conditions are the sorts of engines currently in use by planes on Earth. We don’t need to invent anything or get into details of whether it’s a rocket or turbine engine unless we desire to. We should just be aware that characters may need to remark that they’re switching to “so-and-so power” as they enter a planet’s atmosphere because the space engines they were using might not be suitable. This minor touch adds realism. Slower-than-light (STL) engines might also be used here and it’s up to us to decide a given ship can use such engines both in space and in an atmosphere. This is one way to distinguish between ship types: some vessels might have engines that can be used anywhere and be considered more advantageous than ships that must change propulsion.
Space engines can be divided into two categories: those that allow faster-than-light (FTL) speeds and those that do not. For STL engines, propulsion is similar to atmospheric engines in that matter is ejected, usually from the rear, to propel the ship forward through normal space. This is one reason slower-than-light engines could be used in an atmosphere. STL drives propelling a ship at high velocities can cause time dilation, which is when two observers experience a difference in how much time has passed. Some stories discuss a captain not letting the ship go too fast using those engines, generally, to avoid this problem.
Some FTL engines are discussed next and are all public domain ideas anyone can use.
As the name implies, a ship with jump drive essentially teleports between two locations in an instant. This may be safely called a “jump drive” or something else. The main problem with such technology is that it eliminates all conflict involving travel and not having enough time to reach a destination by an important date. Consider using this sparingly or placing severe limits on how often such a drive can be used, such as it uses too much power, relies on a rare fuel source, is expensive to manufacture, or is too large for ordinary ships. Ships equipped with jump drive do not experience time dilation.
A hyper drive moves a ship into hyperspace, a fictional, separate dimension adjacent to normal space. As a result, ships in hyperspace are often depicted as being unable to communicate with those in normal space. Normal physics, such as the barrier to FTL travel, may not exist in hyperspace, allowing the ship to traverse great distances quickly. It takes time to travel in hyperspace but those traveling this way experience time normally and experience no time dilation upon returning to normal space.
Warp drive is a conceptual FTL drive that is public domain despite being heavily associated with Star Trek. The idea includes multiple velocities of warp, such as warp one being far slower than warp ten. Instantaneous travel is not possible with warp drive. The ship suffers no time dilation and remains in normal space. Despite our use of the term “space”, there are plenty of objects with which a ship could collide, which begs the question of how deadly such an impact would be. Without high-speed automated navigation systems and equally impressive shields, warp speed is unwise.
The previous two chapters focused on how to determine travel times using the sort of locomotion available on Earth-like worlds. Space travel falls under two categories: existing technology from Earth and invented technology. As I’m not a rocket scientist, the former is best left for those in the know to explain. World builders tend to be focused on imagined technologies anyway, and there’s no telling what detail you might want to know and utilize about real technologies. More to the point, the limits of real technology eliminate interstellar travel and therefore whatever we’re hoping to achieve.
The Realities of Space
Writing fiction doesn’t free us from the realities of space, such as the intense cold or lack of oxygen. Some will think gravity doesn’t exist either, but gravity is everywhere and causes all rotation (i.e. orbits). The conceit of artificial gravity has long been accepted so that we only need to address it if we want to, such as designing a rotating ship.
The question we must address is whether to pretend certain realities are overcome by technology (or magic) or not. It’s recommended to be consistent in a single product. For example, in the Star Trek universe, food replicators that make lunch appear from thin air is as unrealistic as the teleportation devices that move matter (including people) between places. Being equally unrealistic (or realistic) is wise and helps the audience accept the reality we’re presenting; otherwise, incongruities creep in. Having food replicators and teleporters but no artificial gravity would be an example, as the gravity, or a simulacrum, would be easier to achieve from a technological standpoint.
When inventing technologies for space, creating a hierarchy of believability might be wise, if we’d like to have some things achieved while others are still imaginary, even to our advanced inhabitants. Maybe we want them to have achieved artificial gravity (so actors have a much easier time on screen) but still have the need to grow and cook food. At one time, the communication devices of Star Trek were considered fantastic but have been eclipsed by reality.
Generally, advanced communication is easier to achieve, as this often means little more than smaller devices with greater distance or computing power or capabilities, and sending of signals (not matter) long distances. Those signals can contain data just like here on Earth. This suggests that an advanced program, such as a hologram or A.I., could be sent vast distances, with the possibility of corruption in transit.
Any technology involving non-living matter is easier to create than something involving living creatures. This is especially true of transportation. Creating a new propulsion system using newly discovered elements from far flung solar systems is more believable than a technology that bends time and space and causes matter to just end up somewhere else in an instant. Such abilities are best seen as rare because making them commonplace implies the characters have other godlike abilities, too, and their lives become too easy, which reduces conflict, the heart of every story.
Where to start depends on our goal. If trying to determine the travel time between two places, follow the steps outlined in “Ship Speeds.” You’ll need to decide on the distance first, then whether the trip is along a coast, the open ocean, or both. Then consider what sort of issues you’d like characters to face on the journey. You may need to slow them or accelerate their travel based on story needs. If trying to decide what weaponry or personnel ships have on your world, the sections on this will assist a decision. The section on ship types will help you determine the style of vessel you want, but when it comes to rated ships, it’s largely immaterial which you choose unless you intend two or more ships to go to war with each other.
It’s beyond the scope of this book to describe all the personnel needed on a ship, but in a fantasy world, we have new humanoid species and occupations that can be added to the typical crew from Earth vessels. This can be true in SF, too, but the crafts there are usually spaceships. Ships often had livestock and even plants, mostly for consumption, which means our invented plants and animals can be aboard, too.
Many fighting ships have military on board for the combat that might ensue when ships entangle (on purpose or not). Any sailor can engage in the fighting, but trained military are typically aboard during fleet actions. We can have such people onboard any vessel as standard crew, their numbers depending on overall ship and crew size. Larger numbers of such warriors will need quarters set aside for them (they may not be berthed with the sailors), but we needn’t go into such details unless desired.
Knights are an obvious choice for hand-to-hand combat. They weren’t on ships during the Age of Sail for the reason of gunpowder: bullets, and by extension cannons, had rendered armor useless. If we lack this issue on our world, then knights might figure heavily in the military aboard. A single knight could be present to represent knightly values or a kingdom on formal terms, or a group could be there in expectation of combat at sea. They can be available for missions ashore. However, even in a world without guns, knights still sink rather handily once overboard. They also make fine targets for archers.
Pirates wouldn’t have knights on their ships and might think twice about attacking such a ship, if knights are assumed to be aboard. Why would they assume this? British ships-of-the-line were known to have marines aboard, so a ship belonging to a country of our invention can, too. Raising the country’s flag might warn off pirates.
Ninjas or other forms of martial artists could be highly prized, due to their superior rope climbing skills and balance on those yard arms. Imagine how quickly they can board an enemy ship at close range.
Aboard a ship, unless there’s a duel of some kind, the fighting is in close quarters, so space constraints would render weapons such as a staff less effective. Consider the weapons used by your warrior class which is routinely assigned to a ship, and whether they’re appropriate under these conditions.
If guns don’t exist on our world, archery is the obvious long-range weaponry fired by one person at a time (as opposed to a cannon). This can happen before and after ships entangle. These can be long/short bows or crossbows that fire flaming arrows into rigging or the hull (or people). Consider where such individuals might be stationed as ships battle.