On 30 September 2014 05:28, Tim <tim@little-possums.net> wrote:

On Thu, Sep 25, 2014 at 07:34:30PM +0100, Timothy Collinson wrote:
> Yes, I may yet go bigger with both commercial and community. Say,
> 40,000,000 apiece. again, not short of space.

I haven't seen the book at all, but something seems a bit off with the
figures. Did you say that the 'mid' quality residential space was
about 4 dtons per person?

Yes, that's right.

Low Quality (Soc 1+) allows for one person two tons.

Mid Quality (Soc 4+) allows for one person per four tons.

High Quality (Soc 8+) allows for one person per six tons.

Luxurious housing (Soc 12+) allows for one person 10 tons.

That seems very small by our spacious surface-dweller standards, even
in cities.

Yes, that's why I was mentally doubling the space even if I didn't formally account for it that way as I had lots of room with my billion tons!

I skimmed a few different city apartment listings, finding
an average of about 10-15 dtons per bedroom, so possibly close to
10 dtons per person for personal living space alone. That does not
include any internal access or shared facilities. Checking out a
couple of apartment building plans, I would add another 40-60% for
those. So I'd estimate more like 15 dtons per person for mid-quality
long-term living areas, still not including larger-scale access
equivalents to streets, walkways, subways, or similar.

Now that's really helpful. Many thanks for that - just the kind of info that's helpful when doing this.

4 dtons seems more suitable for something like cabins or compact hotel
rooms designed for at most medium-term occpancy than for lifetime
habitation.

Yes, I was envisioning the starship 4 tons for a stateroom and thinking it was far too small really. (Even with my double height decks).

It's well below the average living space alone (without
any access) for most of the more crowded cities on Earth. As another
comparison, it's a bit less than half the minimum legal size for
construction of residential buildings in London (again, personal
living area alone).

Of course, the newspapers love those stories where a broom cupboard (closet) has been turned into an 'apartment' in London and selling for some ridiculous price.

Even allowing some room for cultural variations, I would certainly at
least double those volumes given for residential volume, and if you
wanted the sort of spaces typically found inside Western apartment
blocks, quadruple it.

Thank you - just the encouragement I need! (And facts to back it up.) I shall print out those details to use as a bookmark in the right place.

I'm not sure if there is separate provision for volume occupied by
various forms of transit and service access within the station. That
needs to be available not just for residents but also for freight
transport and construction equipment, with large enough cross-section
to permit anything that might conceivably need transporting within the
station. That may include replacement structural members and such.

Hmmm, now there's a good thought I hadn't particularly considered - although I had put some much larger than normal thoroughfares just on principle - you're right, there should be some for the behind-the-scenes stuff as well.

> LOL! Lovely thought for this beasty! But no, it's just 'supposed' to be
> maintaining a geosync orbit.... them's the rules. I can't see a way of
> fudging them.

Just out of interest, what sort of power output and thrust do the
rules say is the minimum permitted for a billion-ton station?

There's a table for non-orbital stations, orbital stations, geosync and geostationary. I'm working on a geosync one so the line reads:

M-Drive percentage: 0.75

M-Drive cost (MCr/ton) 0.5

Thrust 0.5G

(page 5)

So I make that 7.5 million tons of M-Drive costing MCr3.75

Power Plant is as per Book 2: High Guard (p.63)

Rating 1 = 1.5% of displacement

Rating 2 = 2%

Rating 3 = 2.5%

Rating 4 = 3%

Rating 5 = 4%

Rating 6 = 5%

Now it's not clear what rating a station needs (for ships it must be "at least equal to either the manoeuvre drive or Jump drive rating whichever is higher"). Clearly the latter isn't relevant, but I don't have a rating for the M-Drive (unless it's that figure of 0.75 which I guess is possible). Even at the smallest rating on the table, 1, it would be 15 million tons of Power Plant.

Of course for my six million inhabitants - plus a couple more transients - I still don't really have quite enough content to warrant a billion tons. Even if I quadruple the residential requirements above and build in a fudge factor for commercial space and what I'm calling 'community space' which isn't even listed in the rules. So I could shrink the thing and thus lessen the drives. But my original spec said 'spacious' so I think I'll keep the large size!

Anyway, hope this helps!