Thread: Re: [Traveller_TNE] water in ship designs

hmmm, 2 things can protect you from serious cases of radiation overdose
1. distance - the farther away you are the better
2. mass - dirt works real well, concrete less so, steel even less* and yes, water - which works quite well actually and, in the case of nuclear power systems does double duty in cooling the core...

* steel and other metals work fairly well unless there's an "enhanced radiation event" such as the neutron bomb going off in the immediate vicinity...if this happens the surge of neutrons bouncing through the molecular structure knocks enough electrons, protons, and other neutrons etc loose that the metal itself becomes a radiation source.  The initial + augmented radiation storm then has more than enough power to kill (approx 500 rads) but to do so fairly quickly and to incapacitate the vehicle crews and passengers in the meantime.  Values of 1500 to well over 3000 rads and their effects on humans have been calculated...damned if I know how...not sure I want to... figure by the time frame we're dealing with an anyones TU the sciences have it all down pat.

Back to water, in my, admittedly, limited experience and knowledge of the subject, the water that actually gets in close to the core is considered to be radioactive itself and is kept in a closed loop system.  A system of heat exchangers transfers the heat to an open "clean" system which is used for cooling the rest of it down - part of this includes those huge water tower things that are always shown on TV news spots of working nuclear facilities...they need water and lots of it, part of the reason that they like to build near lakes & rivers.  Water that is released back into the environment is supposed to be from the clean water portion of the system and is quite a bit warmer than the surroundings, tropical fish in the far north? 

Above and beyond shielding from solar activity and possible nuclear power systems water would be used:
1. as is normal amongst us to possibly include swimming pools, and,
2. in the case of stations using rotation for gravity control, could be pumped into various locations to offset ship mass for docking at locations outside the core,
3. as reserve/emergency reaction mass

Once your TL gets to the point that gravity control and ships screens handle the average radiation event, I'd expect that onboard water mass would be drastically reduced.

Near a star, or not quite so near, it could be used as part of a solar heating system and with a series of pumps and radiatiors on the far side of the ship may actually help in offsetting heating (act as part of an airconditioner system) if you're getting a bit too close.

Temp differential engines?  As a secondary power source?  Possible, especially near term or as a "primitive" emergency power system on a crippled ship in more advanced tech levels such as traveller.

Astronaughts with gills?  Why would the have to be human at all?

Additional thoughts, water is incompressible, as a liquid it occupies the smallest volume that it can.  Shockwaves travelling through water can be devastating...ergo USN submarine doctrine when for using nuke tipped rockets/torpedoes.  Launch it to land way over there, turn ship 180 degrees from impact zone and run like hell.  Distances of 20+ miles were considered far to close.

In Germany after WW2, engineer teams going through what was left of cities found numerous bunker systems.  Many 2 or 3 or more storys tall.  In order to remove these (preventing use by a very active insurgency - about 10K US casualties in 1946) they put in a relatively small amount of explosives, sealed the structure, filled it with water and then set off the explosives.  This destroyed even very strong bunkers without having to otherwise use charges that would have been so powerful that they'd pose a danger to nearby troops.  Not sure if they cared about the nearby civies at the time.

Tim

wrote:

Water - a good shield for Radiation?

Could we have double-hulls on spaceships and circulate water around 'tween
the hulls?

If we're near a star, it could act as a solar water heater.

Could we build some sort of temperature diff. engine by taking the warm
water and the cold water?

Could future astronauts be equiped with gills and the ship be flooded?

-Joel

SPONSORED LINKS

---

YAHOO! GROUPS LINKS

---

Interesting points Tom, makes sense for the most part however, regarding the shuttle tiles, they don't transmit heat very well, sorta like the carbon-carbon material demonstration my dad used to do in chemistry classes... for his demo he'd take a sheet of carbonized cloth (IIRC) and would hold it in  one hand and swipe it a time or two with a blowtorch.  Because, of the way they make the stuff it wouldn't burn, least not at those temps.  Same thing with the shuttle tiles, they are physically quite weak, you can poke holes in them with your finger, they're made of glass fiber with lot of air pockets in them.  They serve only to protect the shuttle from the heat of re-entry.  cite: documentary on Discovery channel about the shuttle, the last one crashed and what was done to fix the problem.

The electronics and body heat likely go along way to keeping the shuttle warm enough.  Although this does bring up an interesting subject... space is a vaccumm, the "perfect" insulator...the movie on the Apollo 13 mission indicate that after they'd turned off most of their electronic equipment that it got fairly cold in there.  My question would be how cold?  Did they require heaters prior to the accident or was the heat from all the electronic equipment enough?  How does that relate to Mir, Space Lab, and the ISS?

Regards,
Tim

Tom <> wrote:

--- In , <joel@m...> wrote:
>
> Water - a good shield for Radiation?
>
Water is not really a good "portable" rad shield material.  The
shielding really has to have enough atoms to block the radiation
particles/waves in order to work.  A swimming pool reactor (which is
not use for electrical generation) uses a pool of water 20-30 feet
in diameter 8-12 feet deep.  The reactor pile is at the bottom. 
That is a really thick amount of material to put in a spaceship.
RAD shielding can be made thinner by using high-density materials
such as lead or gold.  A solid shield needs similar mass as the
water but takes up far less volume.  When we get to TL 10+ and start
using crystaliron or superdense materials, the shielding gets even
thinner. 
>
> Could we have double-hulls on spaceships and circulate water
> around 'tween the hulls? If we're near a star, it could act
> as a solar water heater.
>
Yes - although it would be tanks and plumbing rather than just open
space between the inner and outer shell. In direct solar radiation
(AKA Sunlight) the whole ship will heat up.  It is more likely that
the water would be used to cool the sun exposed side of the ship and
to distribute the heat evenly throughout the ship. The sun side will
+ 300ºC and the shade side will be -267ºC.  A heat distribution
system should be included as a standard part of the life support
systems.  (The US space shuttle uses orientation for some amount of
heat control - face the black tiles into the sun and the shuttle
heats up - face the white tiles into the sun and the shuttle cools
down.  (Those NASA guys are clever that way.)
>
> Could we build some sort of temperature diff. engine by taking
> the warm water and the cold water?
>
These kind of thermal exchange systems are really not efficient
enough to run a ship.  But in an emergency it might run your life-
support systems.
>
> Could future astronauts be equipped with gills and the ship be
flooded?
>
T20 added Dolphins as an uplifted race.  They also added an aquatic
race.  Neither of these races use liquid filled ships.  Water and
Electrical circuts just do not mix very well.
>
> -Joel
>

SPONSORED LINKS

---

YAHOO! GROUPS LINKS

---