With the Spanish classification system for locomotive wheel arrangements, the system for steam machines.

Steam

With steam locomotives, there are three digits normally and more with articulated locomotives. The digits are written one after another since there are never so many axles to cause confusion.

The first digit corresponds to the number of leading unpowered axles.

The second digit corresponds to the number of powered axles.

The third digit corresponds to the number of trailing unpowered axles.

Examples

Thus:

0-6-0

0-6-0

Under the Whyte notation for the classification of steam locomotives, 0-6-0 represents the wheel arrangement of no leading wheels, six powered and coupled driving wheels on three axles, and no trailing wheels...

 becomes 030

2-6-0

2-6-0

Under the Whyte notation for the classification of steam locomotives, 2-6-0 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This arrangement is commonly called a Mogul...

 becomes 130

0-8-0

0-8-0

Under the Whyte notation for the classification of steam locomotives, 0-8-0 represents the wheel arrangement of no leading wheels, eight powered and coupled driving wheels on four axles, and no trailing wheels...

 becomes 040 'Verraco'

4-6-2

4-6-2

4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...

 becomes 231 'Pacific'

2-8-0

2-8-0

Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and no trailing wheels...

 becomes 140 'Consolidación'

2-8-2

2-8-2

Under the Whyte notation for the classification of steam locomotives, 2-8-2 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

 becomes 141 'Mikado'

4-8-0

4-8-0

Under the Whyte notation for the classification of steam locomotives, 4-8-0 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and no trailing wheels. The type was nicknamed the Mastodon or Twelve-wheeler in North America....

 becomes 240 'Mastodonte'

4-8-2

4-8-2

Under the Whyte notation for the classification of steam locomotives, 4-8-2 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

 becomes 241 'Montaña'

4-8-4

4-8-4

Under the Whyte notation classification of steam locomotives, 4-8-4 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification: 2D2...

 becomes 242 'Confederación'

2-10-2

2-10-2

Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck...

 becomes 151 'Santa Fé'

2-6-6-2

2-6-6-2

In Whyte notation, 2-6-6-2 refers to a railroad steam locomotive that has two leading wheels followed by six coupled driving wheels, a second set of six coupled driving wheels, and two trailing wheels...

becomes 130+031