Numbers in Trains

Clark A.

Member
Kind of a beginner's question. I see/hear locomotives referred to as 2-8-0, 4-4-0, or even one with 4 number spots. What does it all mean?
 
N

nachoman

those are the whyte (sp?) system identifiers for steam locomotives. 1st number - # of pilot truck wheels; 2nd number - # of driving wheels; 3rd number - # of trailing truck wheels. If there are 4 numbers, the middle two refer to driving wheels driven by seperate sets of cylinders, as in an articulated locomotive.

kevin
 

RailRon

Active Member
Clark, have a look at this site .

There you find all the wheel arrangements in the Whyte system plus the type designations in form of a name. So e.g. a 4-6-2 is also called a Pacific, a 4-8-4 is a Northern (but on some RR lines also a Niagara, Confederation, Dixie, Pocono etc..)

The sets with four numbers are for the articulated locomotives (e.g. Mallets). The middle two numbers give the wheel numbers of the driving wheel sets. For an example, the famous Big Boy is a 4-8-8-4.

Hope this helps,

Ron
 

60103

Pooh Bah
Clark:
the numbers convey a lot of information when you're dealing with fairly standard types of locomotives. When it was devised there were only 3 types of wheels that would be found on steam locmotives.
Then they developed articulateds with 2 or even 3 sets of drivers. Then the Pennsylvania made locomotives with 2 sets of drivers on one rigid frame. And Beyer-Garratts with a boilers slung between two engine sets.
So a simple sustem with one punctuation mark no longer could handle all types of locomotives.
 
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