XPost: sci.space.policy, sci.physics   
   From: invalid@invalid.com   
      
   On 10/17/2016 7:14 PM, Fred J. McCall wrote:   
   > jimp@specsol.spam.sux.com wrote:   
   >   
   >>   
   >> It is 10-19 MW-hrs from ore to one ton of steel, not counting fabrication   
   >> into usefull stock.   
   >>   
   >   
   > There seems to be some disagreement on these numbers.   
      
   >>   
   >> A ton of steel is a tivial amount. I have over a half ton of steel just   
   >> in the various things I have built around the house and I'm not building   
   >> any buildings.   
      
   >   
   > Well, let's look and see how many feet of steel beam is 'a trivial   
   > amount'.  Keeping in mind that we can use smaller beams on Mars (less   
   > gravity)...   
   >   
   > A foot of 24" steel beam weighs about 100 lbs.  So a ton is around 20   
   > feet, which sounds trivial indeed until we realize that two foot beams   
   > are preposterously oversized for what a Mars colony will need to   
   > build.   
      
   > A foot of 7" steel beam weighs around 20 lbs.  That gives 100 feet of   
   > beam per ton of steel, which starts to look much better.  And that's   
   > probably still over specified for what they'll be used for on Mars.   
   >   
   > A foot of 3" steel beam weighs 6 lbs.  So if that's all I need I can   
   > get 333 feet of beam out of a ton of steel.  Starts to sound less and   
   > less 'trivial', doesn't it?   
      
   > So it all comes down to how 'fast' you can make steel.  Given low   
   > power reactors I can only make around a quarter ton of steel a day.   
   > But throw together 10 'suitcase reactors' and I'm producing   
   > comfortably over 2 tons per day.  Even if I use Jimp's numbers, I can   
   > make a ton a day.   
   >   
   > That's a lot of steel beam...   
   >   
   >   
      
   what are you smokin ?   
      
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