Water and Power

[esampson]

So I was thinking about water on starships in the Traveller universe (initially with whether life support recycles it or what) and I came across some interesting facts.

The first is that discounting watering the lawn the average person uses approximately 50-100 gallons of water per day. This includes things such as water used for showers, toilets and washing dishes. That corresponds to about 180-350 liters per day. Around half of that will be used for showering. For toilets you can probably assume less around 30 liters. Less than 4 liters of the daily water usage is actually spent in drinking.

Assuming none of it is recycled that adds up to about 2500 liters per week or less than .2 DTons, which is very little (though not inconsequential, especially when multiplied by an entire crew) space.

This leads to some interesting concepts. In the case of military and 'working class' ships we can probably assume very heavy recycling of water. It isn't that the water will take up enormous amounts of space but as an example just a meager Scout/Courier would probably have to set aside nearly 1.6 DTons for water (this would allow for up to 8 crew members for a week).

So for ships of that nature carrying enough freshwater for a trip (with adequate safety margins) isn't practical, but what it is practical for are things such as yachts, especially if you use water from the bath/shower/dishes (with filtering) for things such as flushing the toilet.

If a ship were to have freshwater for drinking, throw away water used by the toilet, and recycle all other water after filtering the water usage per person would be approximately 10 gallons or 35 liters per day. The ship would need a standing supply of, say, 90 liters per person + 250 liters per week. For the example of the Scout ship that works out to 4720 liters or only .35 tons.

So this gives us a figure of about .04 DTons of water per passenger with passengers drinking freshwater and 'throwing away' black water. While that is far from the minimum a ship might need (the minimum being less than .01 DTons per passenger with full recycling) it seems to me like a good number for passengers on a mid passage. In the case of passengers who have booked high passage there wouldn't be any point to more than .2 DTons per passenger (and you could quite likely get by with a lot less with recycling).

Of course space on a ship is precious, so it might be hard to scrape up 20 DTons to set aside on a Nobles yacht, right? Actually, it should be easier than you think.

Every molecule of water is approximately 11% hydrogen by weight. Since 1 DTon of water is 13.5 cubic meters of water that means it weight 13.5 tons. 11% of 13.5 tons means that there is actually a bit more than 1.5 tons of hydrogen per DTon of water.

That's right, water contains more hydrogen than liquid hydrogen by volume.

The biggest problems are that water weighs a whole lot more and the hydrogen isn't immediately accessible. It's pretty easy to break it apart using electricity from a ship's power plant but it still takes time. Because of this you probably want to carry enough liquid hydrogen for the jump drives since they can gobble it up in a hurry, but for your power plant it should be quite possible (and in fact more space efficient) to run on water.

And the best thing about running your power plant on water? Breaking down the water will produce more oxygen than you could possibly need. A human being consumes approximately 5.5 kg of oxygen per week. 1 ton of oxygen is enough for 200 people for 1 week, approximately, and the process of breaking down water for hydrogen releases 8x as much oxygen by weight. That means that every ton of hydrogen a power plant consumes per week produces enough oxygen for about 1500 people.

 

[HG_B]

At the TL's we are dealing with, ~100% water recycling would be trivial and part of standard life support. Especially given the VERY tedious econ model Trav ships operate under given restrictions on available tonnage on a ship..

 

[leo knight]

The conventional showers and flush toilets of today waste a great deal of water. Buckminster fuller had some ideas about this. His showers he called a 'fog gun'. While serving in the navy, he noticed that the upperworks that caught the wind and spray had relatively little grime on them. He designed a washing system using water and compressed air that would spray the dirt away. He claimed an hour's use would only use a pint of water. This was in the far future year of 1938. A link:

http://www.weirduniverse.net/blog/permalink/fullers_fog_gun/

He also designed a 'packaging tiolet' that shrink wrapped waste for later diposal. a link about the whole setup:

http://www.bfi.org/about-bucky/buckys-big-ideas/dymaxion-world/dymaxion-bathroom

Also, a gadget called the Incinolet, or incinerating toilet, saw use in a Mars habitat simulator in Canada. It reduces waste to a fine, sterile ash. Robert Zubrin, the project director, wrote good things about it in his book "Mars on Earth". They tried composting toilets first, which worked sporadically. Crew morale suffered. With plenty of fusion power, maybe an Incinolet would make more sense. Also, no cold seat in the morning! :file_23:

 

[esampson]

The conventional showers and flush toilets of today waste a great deal of water. Buckminster fuller had some ideas about this. His showers he called a 'fog gun'. While serving in the navy, he noticed that the upperworks that caught the wind and spray had relatively little grime on them. He designed a washing system using water and compressed air that would spray the dirt away. He claimed an hour's use would only use a pint of water. This was in the far future year of 1938. A link:

http://www.weirduniverse.net/blog/permalink/fullers_fog_gun/

He also designed a 'packaging tiolet' that shrink wrapped waste for later diposal. a link about the whole setup:

http://www.bfi.org/about-bucky/buckys-big-ideas/dymaxion-world/dymaxion-bathroom

Also, a gadget called the Incinolet, or incinerating toilet, saw use in a Mars habitat simulator in Canada. It reduces waste to a fine, sterile ash. Robert Zubrin, the project director, wrote good things about it in his book "Mars on Earth". They tried composting toilets first, which worked sporadically. Crew morale suffered. With plenty of fusion power, maybe an Incinolet would make more sense. Also, no cold seat in the morning! :file_23:

The fact that Buckminster Fuller's shower was designed in 1938 and still doesn't see real use is part of what made me think about this. Not literally this fact but instead what it represents, the psychological/sociological pressures that would affect certain forms of development. HG_B is absolutely correct when he says that in the technology level of Traveller they should have recycling systems that are so close to perfect that you wouldn't need to worry. In fact I can even seem a simple, if energy inefficient way to make a system to distill water. Simply use electrolysis to break apart the hydrogen and oxygen, capture the gasses, and recombine. There's no chance of a pathogen being carried through the process. It is not particularly efficient but starships produce a lot of energy.

However we also have technology today that lets us filter waste water with practically zero chance of contamination. We don't use it because trying to sell the population of most cities on the idea of drinking water that was at one point in their sewers is a very hard sell, no matter how good the process is. Similarly I would imagine that for a lot of people in the Traveller universe there might be some difficulty with selling the idea.

People who spend large amounts of time inside a ship would probably be much more accepting of such a thing, much in the same way that people serving aboard modern military vessels are very accepting of the fact that they can only take very short showers. Passengers, on the other hand, might be less accepting of such a fact, much like the way that passengers on a modern cruise ship would probably not accept being limited to military style showers.

This was mostly a sort of thought exercise. Since most ships are only out for a week at a time, I was wondering, could they get by with just carrying enough fresh water. Turns out the answer is yes, especially if there are accommodations made to deal with the things that use the largest volumes of water; showers, toilets, and washing clothes and dishes.

Another kind of novel (I thought) solution was to sort of make water on demand. The ship carries a supply of liquid oxygen. Whenever water is used it comes from a cistern which is then refilled with water created from the liquid oxygen and the liquid hydrogen the ship is already carrying. The used water is broken down into hydrogen, oxygen, and contaminants and then rather than recirculating the water the hydrogen is sent on to the power plant (the rate that power plants go through hydrogen appears to be faster than people go through water, so there wouldn't be any real need to store up the liberated hydrogen) while the oxygen is re-compressed for use in more water or the ship's atmosphere.

 

[Carlobrand]

...The first is that discounting watering the lawn the average person uses approximately 50-100 gallons of water per day. ...

Assuming none of it is recycled that adds up to about 2500 liters per week or less than .2 DTons, which is very little (though not inconsequential, especially when multiplied by an entire crew) space.

This leads to some interesting concepts. In the case of military and 'working class' ships we can probably assume very heavy recycling of water. It isn't that the water will take up enormous amounts of space but as an example just a meager Scout/Courier would probably have to set aside nearly 1.6 DTons for water (this would allow for up to 8 crew members for a week).

That would be one of several reasons 4dT staterooms cost so much while 2 dT cabins are so cheap. You only actually need something like a gallon or so a day, and you get some of that from food. In fact, if you manage somehow to consume more than about 4 gallons a day, you've got a problem: you're likely exceeding your kidneys' ability to filter out the excess, and you're going to run into serious and possibly fatal electrolyte problems. Ergo, while you can fly from A to B in real comfort with a hundred gallons a day and a full-scale plumbing set-up, you could actually manage the entire trip with a single ten-gallon tank mounted above a sink, and a chemical toilet or some such alternative for waste. You'll just be kinda stinky and royally sick of chemical toilets at the end of it, which is not something the average Cr10,000 passenger pays a ticket for - unless of course you are improvident in your use of water, in which case you've got more serious problems in store. :devil:

 

[leo knight]

The fact that Buckminster Fuller's shower was designed in 1938 and still doesn't see real use is part of what made me think about this.

Indeed. I read about it in the book "Buckyworks" by J. Baldwin, a student and fan of Fuller. He had tried a few versions of the fog gun. I gather it's a bit like the power washers at the car wash. Baldwin said they all stung like the dickens. Of course bucky claimed that his fog gun didn't sting.

Yeah, given cheap energy, why skimp? A few miles from me rests the submarine Torsk. They desalinated I forget how many gallons of fresh water. Most went to the batteries, not the crew, and this was powered by diesels.

 

[HG_B]

However we also have technology today that lets us filter waste water with practically zero chance of contamination. We don't use it because trying to sell the population of most cities on the idea of drinking water that was at one point in their sewers is a very hard sell, no matter how good the process is. Similarly I would imagine that for a lot of people in the Traveller universe there might be some difficulty with selling the idea.

Yes that can be tricky. I think it is tied to education. You or I (and probably 99% of others on this board) know that taking waste water and purifying it via high temp or the like makes for perfectly acceptable drinking water. But we are a self selected "group".

 

[Carlobrand]

Yes that can be tricky. I think it is tied to education. You or I (and probably 99% of others on this board) know that taking waste water and purifying it via high temp or the like makes for perfectly acceptable drinking water. But we are a self selected "group".

So are the (hypothetical) folk who take starships to other stars.

Seems to me that it would not be terribly difficult to run a separate "grey-water" system, deliver fresh water to the taps and showers, recycled water to the toilets and laundry. That would cut consumption by about 15-20% while addressing any finickiness about drinking recycled water. You can also about halve consumption by introducing water-saving devices like sinks with sensors that only turn on when there's something under the tap or sinks with automatic shut-offs that turn the tap off after a few seconds of flow, low flow showerheads, and suchlike devices.

 

[HG_B]

So are the (hypothetical) folk who take starships to other stars.

Seems to me that it would not be terribly difficult to run a separate "grey-water" system, deliver fresh water to the taps and showers, recycled water to the toilets and laundry. That would cut consumption by about 15-20% while addressing any finickiness about drinking recycled water. You can also about halve consumption by introducing water-saving devices like sinks with sensors that only turn on when there's something under the tap or sinks with automatic shut-offs that turn the tap off after a few seconds of flow, low flow showerheads, and suchlike devices.

That's true. Good idea on the different systems also.

 

[Fritz_Brown]

He also designed a 'packaging tiolet' that shrink wrapped waste for later diposal.

So, sort of like using baggies when you walk your dog? Maybe a design for a Vargr ship? :smirk:

Also, a gadget called the Incinolet, or incinerating toilet, saw use in a Mars habitat simulator in Canada. It reduces waste to a fine, sterile ash. Robert Zubrin, the project director, wrote good things about it in his book "Mars on Earth". They tried composting toilets first, which worked sporadically. Crew morale suffered. With plenty of fusion power, maybe an Incinolet would make more sense. Also, no cold seat in the morning! :file_23:

This would require some major safety features. Bad enough when a water-based toilet backs up......

However we also have technology today that lets us filter waste water with practically zero chance of contamination. We don't use it because trying to sell the population of most cities on the idea of drinking water that was at one point in their sewers is a very hard sell, no matter how good the process is.

When you speak of contamination, you're just thinking of particulate matter and pathogens, it seems. But, a major problem nowadays in filtration mechanics is removing all of the chemicals in waste water - especially pharmaceuticals (including hormones and such). A lot of modern systems aren't nearly as good at cleaning those out as previously thought. (Yes, this is dismissing the idea of fusion-powered distillation.)

People who spend large amounts of time inside a ship would probably be much more accepting of such a thing, much in the same way that people serving aboard modern military vessels are very accepting of the fact that they can only take very short showers.

"Navy showers" have two components: scarcity of water and number of users. On nuclear aircraft carriers the first component goes away almost entirely. There are occasions when the water processor or the nuke plant is down, but those aren't terribly frequent.* If you plan your day around showering when no one else is doing so, you can take "Hollywood" showers. (Oh, almost forgot that water can be at a premium also during catapult operations, as that takes a LOT of steam.)

* Mind you, this is based on personal experience. And all the experience aboard carriers was during training exercises, and not after having been at sea with 5 months of deferred maintenance. My experience with that was aboard an old-fashioned cruiser.

 

[McPerth]

However we also have technology today that lets us filter waste water with practically zero chance of contamination. We don't use it because trying to sell the population of most cities on the idea of drinking water that was at one point in their sewers is a very hard sell, no matter how good the process is. Similarly I would imagine that for a lot of people in the Traveller universe there might be some difficulty with selling the idea.

After all, most water has been at one time or other in sewers or at least contaminated. If you live downriver of a large city whose sewers probably go there, the river's water (from were probably comes the water at your house) will probably carry some contamination from the sewers of the city upriver, and yet can be made potable for people.

See also that the rests of sewage water (mostly from faeces) can be valuable as fertilizer in some planets with marginal biosphere...

 

[HG_B]

After all, most water has been at one time or other in sewers or at least contaminated. If you live downriver of a large city whose sewers probably go there, the river's water (from were probably comes the water at your house) will probably carry some contamination from the sewers of the city upriver, and yet can be made potable for people.

Dumping raw sewage into rivers is illegal in most areas. Don't know about your country... Although, I do remember Ría de Bilbao looking pretty bad when I'd walk to work that way. It was very slow moving most of the time. So, it could have just been from that.

 

[McPerth]

Dumping raw sewage into rivers is illegal in most areas. Don't know about your country... Although, I do remember Ría de Bilbao looking pretty bad when I'd walk to work that way. It was very slow moving most of the time. So, it could have just been from that.

Fortunately laws have changed and you're right, most such water would be (at least) partially purified, but even so they have been in sewage, as whould any purified water in a starship as told.

And even so, as someone has pinted, there is a problem with pharmaceuticals in river waters...

 

[HG_B]

And even so, as someone has pinted, there is a problem with pharmaceuticals in river waters...

Yes, that would require distillation to remove 100%. But, fortunately that's easily done aboard a starship.

 

[McPerth]

Yes, that would require distillation to remove 100%. But, fortunately that's easily done aboard a starship.

But distilled water cannot be drunk, unless you want to have severe intestinal problems (due to osmotic celular lysis). Once distilled it must be salinized again.

 

[HG_B]

But distilled water cannot be drunk, unless you want to have severe intestinal problems (due to osmotic celular lysis).

That's medically incorrect. As long as your food intake has sufficient salts & minerals it is no problem. A common misconception though.

 

[Xerxeskingofking]

I am told that if you look at the amount of water taken form the River Thames in southern England, you get a figure three times as large as the amount of water actually in the river. the only possible conclusion is that someone living in London is drinking water that most likely has been though at least one other person before they drink it.


just a little food for thought.

 

[Zutroi]

IMTU:

Fresh water goes to the taps for drinking and washing =>
Gray water from here goes to use as flushing water =>
Black water from flushing goes into the fuel processor and turned into =>

Hydrogen for energy
Oxygen for breathing
Sterile organics that are ejected during de-orbit, or sold if there is a demand dirtside.

 

[Carlobrand]

IMTU:

Fresh water goes to the taps for drinking and washing =>
Gray water from here goes to use as flushing water =>
Black water from flushing goes into the fuel processor and turned into =>

Hydrogen for energy
Oxygen for breathing
Sterile organics that are ejected during de-orbit, or sold if there is a demand dirtside.

Works great for a merchantman. Some long-range military ships are going to want a tight recycling system instead.

 

[Timerover51]

However we also have technology today that lets us filter waste water with practically zero chance of contamination. We don't use it because trying to sell the population of most cities on the idea of drinking water that was at one point in their sewers is a very hard sell, no matter how good the process is. Similarly I would imagine that for a lot of people in the Traveller universe there might be some difficulty with selling the idea.

I am not sure where you live in the US, but for Chicago and Milwaukee, once the water goes through the sanitary districts plants, it goes back into Lake Michigan, and goes back into the faucet. Milwaukee has had problems with heavy rains overloading the sewer system resulting in raw sewage flowing into Lake Michigan, and every once in a while, Chicago has the same problem. Main result is beach closing in the summer. No one stops using the drinking water from the Lake.

As for usage, the US Army uses the following for estimating water requirements for troops. Material comes from FM 101-10, STAFF OFFICERS'
FIELD MANUAL ORGANIZATION, TECHNICAL AND LOGISTICAL DATA, 1959. Same data is in the current version.

Temporary camp: 5 gallons per man per day, Desirable for all purposes (does not include bathing).

Temporary camp with bathing: 15 gallons per man per day, Includes allowance for waterborne sewage facilities. system.

Semipermanent camp: 30-60 gallons per man per day

Permanent camp: 60-100 gallons per man per day (that would include watering the lawns.)

One cubic meter of water equals 264.172 US Gallons, or sufficient for 17.6 men per day including bathing and toilet facilities. Assuming ZERO recycling and simple storage of used water, a 16-man ship would require 7-8 cubic meters of water and another 7-8 cubic meters of storage tankage for a standard Jump. That is slightly over 1 Traveller displacement ton of volume. For safety, that probably should be doubled. Realistically, you would have a very high level of water recycling onboard ship, with any wastage being made up by water from food consumption.

Note: This would hold true for men, and probably Vargr. Aslan would require more due to their greater bulk and meat diet. K'Kree are going to require a lot more, based on equine water requirements.