JWR,
I have read with great interest articles posted on your blog. Scott’s article was a good read but left me scratching my head. I am no math whiz but dropping an extra two tons onto a residential second floor seems a little unsafe. I know Scott did not mention the overall room dimensions or joist sizing, or extra precautions he took, but overall I thought a residential floor is generally rated to a safe load of 40 pounds per square foot. For a 10’x12′ room that would be 4,800 pounds. A box of pennies is 3.25 inches tall, 4 inches wide, and 8.5 inches long. To get a 10 foot span, 4 feet tall would require 210 boxes (14 boxes long and 15 boxes high). At 20 pounds a box, that is 4,200 pounds. I will assume some other things go into the room like a bed, dresser, clothes, not to mention Scott. The remaining 600 pounds of safe live load can be eaten up fairly quickly and I would suspect it to be much greater than 600. All this and the pennies are only on the short wall. When he rounds the bend for the 12 footer he will be adding an additional 5,100 pounds. At that point, not only will the safe load be exceeded, but the theoretical load might be as well. Scott’s second floor could end up on the first floor.
Another consideration is “shear” because all of the weight is being put along the wall edges. All in all, I would suggest [consulting a structural engineer and] a little beef-up to the structure before adding all that weight to a room. Scott seems to be quite advanced at keeping safe so I am sure he will dot his “i”s and cross his “t”s before loading up. I hope his doesn’t have to lug all those pennies back downstairs. – G.L. in D.C.
Jim,
In reference to the recent piece about multiple uses of pennies versus nickels, I just wanted to add one more reason to invest in pre-1981 [1 cent piece] pennies versus [5 cent piece] nickels which you could use as academic research for your books: shaped charge backings. Ideally, the nickel is a better investment, but a diversification between the two would provide materials that may be needed and in short supply. – Skip R.
JWR Replies: The density of copper and nickel are very close to each other. (Copper is .323 pounds per cubic inch, while nickel is .309) So they would have essentially comparable utility in making shaped charge backings. Copper only has a slight advantage.
It is more important note that the melting point of copper is 1,981° (Fahrenheit) and nickel is 2,646°. So I can see the utility of keeping plenty of older pennies around, for lost-wax casting. But my advice on that use is of course hypothetical, since it is currently illegal to melt pennies and nickels for profit in the U.S., and illegal to export them in bulk. I expect that this law will be repealed, once nickels of a new composition (probably stainless steel) reach wide circulation.
Gresham’s Law dictates that the new (debased) coins will drive the old (genuine) coins out of circulation. I predict that once the base metal value of a current composition nickel hits twice it face value (“2X face”), they will disappear from circulation within a year. Presently, I estimate less than 1/10th of 1% of the U.S. population is actively saving nickels. But just wait until 20% of the population does so. Poof! They will be gone, seemingly overnight.