Traincounting

So, I was watching TV or something a week or so ago and someone was talking about a "4-4-0" train engine. I've seen that notation before, probably playing Railroad Tycoon or something, but never knew what the numbers meant.

Turns out, they refer to where the wheels are on an engine. The first number are the little wheels up in front, like under the grill. They're just there for stability, I guess. The second number are the big, powered, chugging wheels in the middle. The third number are small, non-powered wheels in the back, I assume for balance and stability again.

When the engines got bigger, the driving wheels got broken up into two sets, each individually powered, which let trains navigate turns better. They just have another middle number like "2-6-6-2." Still pretty easy to understand.

So naturally someone had to go screw it up. Now they use letters instead of numbers for axles. So, A is 1 axle (2 wheels), B is 2 axles (4 wheels), etc. This is for the big driving wheels only. Little wheels seem to be always in the back of their set (yeah, they mix sets now. Don't ask me why, I'm not a train expert.) Little wheels are designated with an "o". Except (of course there's an 'except,' I told you they screwed it up) when it's a small unpowered wheel set between two powered ones, which is designated "A1A".

So now there's a train called "Bo-Bo-Bo-Bo" as well as "Bo-A1A." I can only imagine Bo Peep is next.