As most of you know, I am obsessed with trying to acquire all of the Environmental Rail Road keys. These keys typically have round bows with a hole in the upper middle, a serial number on one side, a three digit number on the other, they have 3 sections that are offset and make up the keys "bitting" and are usually cast out of steel or brass.
Rail roads prefer the 3 disc versions of this padlock because they operate while frozen, clogged with mud, wet, impacted by dirt or debris, etc. If they used a padlock with more discs, turning of a corrupted cylinder would be harder, and may cause the key to break due, to the added friction of the additional discs.
I have never been given a conclusive answer to how many RR keys there are. But I have a 112, so we can assume for now that there are atleast 12.
Im going to include pictures of keys. I ask that these pictures not be copied or shared with other sites. These photos are from my personal collection.
I hope you enjoy!!