Whyte's Locomotive Classification System

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Category: Fundamentals

Published on Tuesday, 03 January 2012 20:43

Written by Super User

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A system developed by Frederick Whyte in the 19th Century to typify steam locomotives using the arrangement of their wheels. The system counts the number of Pilot Wheels, Driving Wheels, and Trailing Wheels. Thus a 4-4-2 would have four pilot wheels to guide the locomotive, four driving wheels for power, and two more unpowered wheels at the rear.

Many wheel arrangements were customarily also given a name. A 4-4-2 is traditionally known as an Atlantic type. See the examples below:

Freight:

• 2-6-0 Mogul
• 2-6-2 Prairie
• 2-8-0 Consolidation
• 2-8-2 Mikado
• 2-8-4 Berkshire
• 2-10-0 Decapod
• 2-10-4 Texas

Passenger / Dual Service:

• 4-4-0 American
• 4-4-2 Atlantic
• 4-6-0 Ten Wheeler
• 4-6-2 Pacific
• 4-6-4 Hudson
• 4-8-0 Mastodon
• 4-8-2 Mountain
• 4-8-4 Northern

Articulated (Multiple Sets of Drive Wheels):

• 4-6-6-4 Challenger
• 4-8-8-4 Big Boy
• 2-6-6-6 Allegheny