Spaceships, Floor / Deck Plans, Volume and Hexes
 

Greetings, all!

Trying to figure out the amount of space, I see something troubling. According to the author's expansion, an SM+8 ship's systems provide about 16-50 one-yard hexes each. A Habitat module for SM+8 provides 6 Cabins, with each cabin being suitable for accommodating two people.
That's somewhere between 1.33 to 4.16 hexes per person.
A single one-yard hex is the equivalent of 0.54m² (0.64yd²). At best, this means 2.24m² (2.66yd²) of place per person.

How is one supposed to fit a bed, let alone a cabin, into that amount of space?

Thanks in advance!

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

I ran into this when I started trying to create deck plans based on those designer's notes. The first thing is to go with the upper end of the range for habitat modules. In this case, I wouldn't bother with less than 45 hexes per system. Second, think submarines rather than cruise ships, let alone buildings. Most crew will sleep in stacked bunks, so two-ish hexes will sleep two crewmen.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

A bed is only about 1 yard by 2 yards; it should fit within 2 hexes.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

I was looking for cabin sizes, not bunks. For bunks, there's actually 0.66 to 2.08 hexes per person total (apparently both for the room and the bed-slot).

And if a bed is 1 yard by 2 yards, that makes it 2 square yards. A hex is 0.64yd², so it takes 3.125 hexes for the bed alone.

I wonder if calculating volume from SM is actually a better idea.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

First, the area of a hex isn't 0.64 square yards - it's 0.86 square yards. I'm not at all sure where you got 0.64 square yards from.

Second, yes a bed will extend a *little* bit into the corners of the 'edge' hexes, but it's close enough.

Third, beds are still likely to be bunk-beds even in Cabins.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Yup, when I ran a hard-SF space campaign, most astronauts got a coffin which was their room, entertainment, personal storage and bunk, all-in-one. Since everything was in zero-g, habitat sections resembled hives, with bunks on every wall.

Y'know, like this.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Imagine an hexagon, now name the edges A, B, C, D, E and F.

If 1y is from the edge A to edge D, then it is 0.64952y², rounded to 0.65y²
If 1y is from line AB to line DE, then it is 0.866y²
Thats a 4/3 difference.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

The area of a hexagon equals 3×sqrt(3)×edgeLength²×½; for a 1-yard hexagon, the edge equals ½yard. So 3×sqrt(3)×½×½×½ = 3 × sqrt(3) × 0.125 = 0.64 yd².

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Er, the edge length of a GURPS hex isn't half a yard. The edge length is about 0.58 yards.

A GURPS hexagon has a side-to-side length of 1 yard (so to travel through one whole hex you travel one yard). Call this side-to-side length 'd'. The area of a hexagon is sqrt(3)/2 * d^2, or in this case just sqrt(3)/2, or 0.866.

I think what you meant was that the vertices are A, B, C, D, E, and F.

A GURPS hexagon has a distance of 1 yard from line AB to line DE - that's the distance someone would need to travel to cross the hexagon from a hex directly below it to the hex directly above it.

The distance from one vertice of the hex to the opposite one doesn't matter at all; it's not something that's within the GURPS definition of the hex and has no relation whatsoever to hex-based movement.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Sure, but revising your thinking on bunk size allows you more room for other necessary uses of space. A double-occupancy cabin could be, say, five hexes, with three-ish hexes left over for a share of common space like a kitchen, mess hall, and bathroom facilities.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Except for a jail cell or luxury suite I doubt you have much more then a small sink, if that. On most ships you would have a mess hall and shred bathrooms.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

There's also the Establishment habitat unit (bar, brothel, casino, gym, massage parlour, nursery, salon, classroom, or retail store), which provides enough space for 20 patrons and 3 staff in the space of 2 cabins. Which is a total space of 5.32 to 16.64 hexes.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

I'm currently looking real hard at the idea of just calculating volume based on SM and dividing it by the systems involved. But I'm not sure which way to go: calculate the volume of a sphere of the same SM? (Spheres count as 2 SMs higher than their diameter would indicate.)

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Naw. Just multiply the mass by some factor; when I wanted to calculate volume of a ship I just used Mass in Tons * 100 cubic feet/ton (which is an average density of 20 lbs per cubic foot).

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Do it based on the ship's actual shape. If the ship is approximately a sphere, do it as a sphere. For more typical non-streamlined vessels, a rectangular box with width=height=(length/2) would probably work. For streamlined ones, the width and height may well be 1/4 (or less) the length. This should give a decent approximation.

EDIT: I wish I had my book with me, but it occurs to me that a rectangle with length/2=width is 1 SM larger than its height would indicate. A 2-yard-long, 1-yard-wide/high ship would be SM+1 under that ruling, while its face (a 1-yard square, so SM-2 +2 for being a square) would be SM 0. So, height/2=width may well be the rule for streamlined vessels, meaning unstreamlined will be closer to equal. A 1.5x1x1 yard vessel would be SM+0 from the side (SM-1, +1 for being "boxy") and SM+0 from the front (SM-2, +2 for being a square).
So, it may be more accurate for unstreamlined to have (length*2/3)=height=width, while streamlined are (length/2)=height=width.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

A hex is one yard wide, but it's not one yard high.

From Kromm in answer to my question:

> If so, what *is* the volume of a hex (not sure if the height is 1 or
> 2 yards, also).

Canonical hex height for powers and magic is in fact 12' (four yards),
and has been since 1986; see pp. B101, B239 for the current references.
Volume is thus ~93.53 cubic feet, or ~3.46 cubic yards.

Thanks!

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

The Spaceships system says just about nothing about the shape and size of a ship. It does, however, say something about its volume - specifically because it says something about the ship's mass. As I said in my previous post, the best way would probably be to take the mass and multiply it by the density.

Also, the Pyramid Designers Notes apparently assume a density of less than 15 cubic feet per ton or more than 133 pounds per cubic foot; this is a ridiculously high density, making a Habitat more than twice as dense as water; it apparently assumes that a very large fraction of the habitat is solid metal. The density of armor is apparently on the order of 1,333 pounds per cubic foot, which is about three times as dense as steel.

EDIT: This assumed a hex height of 2 yards for deckplan purposes; if it's supposed to be 4 yards, that's a ridiculously high deck and it'll halve the density figures I gave.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

As I said, I don't have my books with me, but I seem to recall the SM table giving an approximate length for each SM, even though mass was the emphasis. Failing that, SS does use SM for purposes of targeting, so determining volume based on that should work.

Not that using density wouldn't work, of course, but I'm somewhat-unconvinced that we can decide on a semi-accurate density very easily. With what I'm proposing, an SM+8 unstreamlined vessel (30x20x20 yards) has a volume of around 12000 yd^3, while a streamlined one (30x15x15 yards) has a volume of around 6750 yd^3. This is going to make things a good deal more cramped on the SL vessel (assuming we have systems each take an ~equal chunk of space), which is as it should be (although these numbers may have a bit too much of a difference).
An SM+8 sphere would have a volume of around 33000 yd^3, making it the roomiest option thus far.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Those figures can vary hugely. Spaceships gives rough estimates for length, but they're not meant to be taken literally.

By RAW, a streamlined vessel of the same SM has about double the length of a non-streamlined vessel. That won't make it more cramped;) (it should also have the same volume as a non-streamlined vessel; no idea why it would have less, as the density of the ship shouldn't change just because it's streamlined)

I'm not sure why you're unconvinced about being able to get a semi-accurate density. It's not exactly all that difficult; we should be able to at least assume that the ship will at most be as dense as water (most likely less so); this is because ships are likely to be roughly as dense as sea ships, which have to be less dense than water in order to float.

Even if we assume a density equal to water, we get a mass-volume multiplier of 32, yielding 32 cubic feet per ton. Thus, an SM+8 ship should have a volume of 32,000 cubic yards or higher.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Something with the same SM from the side and -1 SM from the front/back should have less volume (and thus higher density if it's the same weight) with that SM all-around.
As for the SL vessel being twice the length of the US, I can't figure out any way to make that work. 2x length is going to correspond to +2 SM, meaning there needs to be an effective loss of -2 for targeting purposes. The only way to get this to work would be if a US is a square box/sphere while the SL is long enough that it doesn't get any + to SM from its width... but at the that point the SL vessel would be targeted at -2 from the front/back, rather than at the -1 given by SS.
Looks like this may be one of those cases where the abstract nature of SS makes such an analysis break down...

I don't see why a spaceship would need to have a density comparable to a sea vessel. With that said, however, I seem to remember calculating that an SM+0 spaceship would be around 200 lbs under the SS system, which isn't too far off from the weight of an SM+0 human. Considering my system breaks down when trying to apply it to the SS rules, I'd say going with density equal to or slightly less than water would indeed work just fine.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

Do remember that SM in the Spaceships system isn't about size - it's very specifically only a measure of mass.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

It's also used for targeting the vessel, and decreases when you target a SL ship from the front or from behind, meaning it's also (in a highly-abstract way) measuring the vessel's dimensions. I was hoping to be able to use this to calculate a vessel's volume. Clearly, I was wrong.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

I would start with the mass, and give an estimate of how dense each type of component will be. Cargo holds the least, habitats next, etc.

There are some estimates of this sort on the Traveller forum.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

I had the opportunity to visit a Russian sub in San Diego. And holy moly, but it was a claustrophobic experience. The crew was almost hundred, altogether, hot-bunking in small bunk beds, slotted into the walls with three beds stacked together, the lowest almost on the floor. I think there was only two toilets, too. Cramped corridors, bulkheads with circular openings just barely big enough for me to duck through without needing to try and slide through head first. So yeah, for very limited-space configuration warship, I could easily see three bunks in 2 m2, and those bunks hot-bunked (shared by 2 or even 3 crew-members, so that there is always someone sleeping there). So you could fit 6 - 9 people in 2 m2, and given that the ceiling wasn't too high either, it comes to less than 1 m3 per person. Add the narrow corridor in the middle and you are still well below 1.5 m3 per person.

Re: Spaceships, Floor / Deck Plans, Volume and Hexes
 

But that's exactly the point: those are bunks. A single 'cabin unit' can contain either a bunk (4 people), a cabin for 2 people, a luxury cabin for 1 person, or one half of an establishment (bar, brothel, casino, gym, massage parlour, nursery, salon, classroom, or retail store) which can serve 10 patrons (20 for two cabin units worth). Now, one could argue about whether a normal cabin has a toilet/shower, but a luxury cabin worthy of the name definitely does.