On Fri, May 7, 2010 at 11:49 AM, Thomas Thrien <[email protected]> wrote:
> > > ----------| Am 07.05.2010 11:06 schrieb Troy Guffey: |---------- > > On 5/7/10, Roger Burton West <[email protected]> wrote: > > > >> It's not as simple as that even in the small spacecraft we have now. > >> (For example, there may be a non-atmospheric oxidiser present; even if > >> there isn't, things cool very slowly without atmosphere to provide > >> conduction and convection, so they may just flare up as soon as you let > >> the air back in.) > >> > > OK, make it a 3 stage process: > > 1. Vent to vacuum. > > 2. Repressurisze with pure nitrogen, or an inert gas to cool. > > 3. Restore normal atmosphere. > > > "Vent to vacuum" may be not that easy. A structure housing 100 Million > people is huge, so the distance to the next outer wall may be great. > Evacuating (from people) of large sections of the habitat are a > challenge in its own right, than evacuating it (from air) may cause > additional problems. Just to create some figures: if we assume that each > inhabitant has an average living space of 40 squaremeters (all over all) > with a headroom of 3 meters, we will end up with a sphere of about 7000 > m diameter. Add space for offices, storage, more spacious leisure areas, > agriculture space and you will end up with even a larger ball. As David > talked about a "set of habitats" it will likely have another shape or > consists of multiple elements, but the required volume remains the same, > and the probability that the fire location is far from vacuum remains > fairly high. Therefore I fear, fire fighting has to be done the > traditional way in most cases, vacuuming a place of fire is only a last > resort - when a fire has got that big, it may have already killed hundreds. > > It's a collection of habitats, (the system information players get will say "thousands", with only a handful named or described, which gives room to insert a new one at need...) with the most populous of them being the Zoo. the central part of the zoo habitat is a cylinder about 4000 meters in diameter, and about that long, spun to about 1g, which houses an actual zoo. With elephants. And tigers. There's a 300 meter spine running down the axis, which houses mechanical equipment, the lighting, and a handful of very, very, fancy apartments, the zoo offices, and so on. there are additional, non-rotating, extensions on to that, which house probably 20 million or so. The facility that houses the main starship docking facility and shipyards is the biggest, it's got space to dock 2000 ships (and ships in the setting are *huge*; typical is a cylinder 40 meters diameter, and 1200 m long.), and is about 40 km long, but mostly not very large in diameter. it's got a few million permanent residents, and depending on what's in dock, as many as 10 million transients. Fire fighting in space habitats is hard, but there are some advantages. First, most structures are going to reasonably well compartmentalized. So it should be possible to seal the area of the fire. Depending on what the fuel load is, that may be enough to let it burn out. Second, there aren't many worries about stratospheric ozone, nor greenhouse gases, so lots things we can't use on Earth for routine firefighting are available (haloalkanes, baby, haloalkanes!). Contrary to popular belief, most halon fire extinguishing media aren't (terribly) toxic, and are safe for short term exposure. (There are some unexpected health risks of being around a discharging system: deafness, because they're really loud, and cyro-burns, because they're ejecting a really cold liquid that's boiling. Depending on the agent, there are neurological effects, but mostly those are at higher than fire-suppression concentrations, or require moderate term (10 or 20 minutes) exposure. So it's quite possible to rig fire suppression systems everywhere. (I don't know if it would be economical, but I bet it would be for TL10 societies, who are just insanely rich. And since habitats are supposed to be a closed enviornment, all the air can be collected, and most of the halon recovered.) Fire drills would be totally drilled into these people from birth. Remember, not only have they spent their whole lives in a habitat, so have the last 50 generations of their ancestors. -- David Scheidt [email protected] _______________________________________________ GurpsNet-L mailing list <[email protected]> http://mail.sjgames.com/mailman/listinfo/gurpsnet-l
