What do these numbers mean on train vehicles? Example --> 2-8-2 BLI Mikado?

railohio

Active Member
Dec 29, 2000
999
0
36
2 leading wheels (one axle)
8 driving wheels (four axles)
2 trailing wheels (one axles)
 

kitsune

Member
Sep 10, 2006
114
0
16
45
It's the Whyte system of engine classification. Used primarily for steam engines, but also for some electrics.

The first number represents the number of wheels on the lead truck, if any. If there is no lead truck, the number is 0.

The last number is the number of wheels on the trailing truck, if any. If there are none, zero is used.

The middle numbers represent the number of driving wheels. If the engine is articulated, there will be more than one number here.

For example, your 2-8-2 is a Mikado.

A 4-6-4 is a Hudson, while an articualted Challenger would be called a 4-6-6-4.

A switcher, with no leading or trailing truck, would be something like an 0-6-0 ot an 0-8-0.
 

MasonJar

It's not rocket surgery
Oct 31, 2002
5,362
0
36
Ottawa, Canada
Visit site
But some names are duplicated, according to Wiki... especially "decapod" which in fact has 12 wheels in the most common appelation (2-10-0 - "Russian" decapod). But apparently the 0-10-0 was also a decapod (rarely), and Southern Pacific called their 2-10-2 a decapod as well.

It is interesting to note that the "0-X-0" switcher type engines in that table are listed as "X-coupled" when "coupled" could be applied to any loco with that number of driving wheels. E.g. 4-6-0, 0-6-0, and 4-6-2 are all "six-coupled" locomotives.

Andrew
 

kitsune

Member
Sep 10, 2006
114
0
16
45
MasonJar said:
It is interesting to note that the "0-X-0" switcher type engines in that table are listed as "X-coupled" when "coupled" could be applied to any loco with that number of driving wheels. E.g. 4-6-0, 0-6-0, and 4-6-2 are all "six-coupled" locomotives.

Thats intentional. Generally, for example, all "six coupled" engines will be within a similar weight range and fuel consumption range. They will generally have similar maintenance loads as well. While this is only a general rule, in the days of Steam, when you were lucky to get two engines of the same class to even behave the same, this was as close as you could get to saying "Geep" or "SD".