Cananea Ore Bins
I found these drawings of one of the Canaea Ore bin on page 277 of “The Design of Mine Structures” by Milo Smith Ketchum published 1912. These ore bins were located at the mines at Cananea, Mexico. This can also be found on page 170 of “Mining Library … : Engineering and mining journal.” also published in 1912. Here it mentions that “The bin has a bottom sloping at 45°, and the inside is lined with sheet iron 3/16″ thick, in which the holes for the nails are countersunk. This slope at the bottom has been found sufficient for the Canaea ores, but it is well when building bins with a sloping bottom to bear in mind that heavy sulphide ores of copper when coming damp from the mines are apt to pack in a bin having a slope of 45°…” .. the author goes on about such packing was observed elsewhere and how the practice was to double the front posts since almost all the weight is thrown against them. This is GOOD INFO .. what we want when attempting to model something like an ore bin. GREAT STUFF!!
REFINED – A BIT
Made a few minor changes – mostly to fit the chutes I 3d designed. The 9″ height was pretty much ‘set in stone’ since the On18 lead from the mine was already in place. I had to adjust the height of the bents a bit .. but this is “good nuff” as I can do any final height adjustment with stone/concrete footings under the sills.
THE ‘WHY’ OF SKETCHUP
Ok .. not the ‘only’ why .. but a major one. When creating the bin I made each framing member a separate object. That means I can pull the bin apart (well .. a copy) and arrange and dimension the parts. What I am doing is creating my own plan that I can use to create a scale model. Here I have arranged the frame that supports the bottom of the bin. I had previously determined to use 1/4″ square poplar dowel from Lowes as it is easy to get my hands on. Poplar is harder than Basswood but not impossibly so. That 1/4″ wood makes up the cap and frame of the support.
In Sketchup you can set up the scale to print. Example .. you can set 1 inch in in the printout and 1 inch in Sketchup where you will get a print exactly the same as you created in Sketchup. IF I had drawn the bin full size then I would simply set 12 inches in Sketchup and .25 inches in the printout for 1:48 .. if I wanted plans in HO then I would set it to .138 inches in the printout. Converting from full-scale – say 12 inches to a foot in your scale simply divided 12 by the scale. Example: 12/160 = .075 inches.
In my case I changed the camera from ‘Perspective’ to ‘Parallel Projection’ and ‘Standard View’ to ‘Front’. I could then set the print so 1/4″ in the printout equaled 1/4″ in Sketchup (I had drawn this to 1:48 scale) and I had plans I could work directly off of.