| Term |
Description |
| 0-4-0 |
No leading or trailing wheels and four coupled, driving wheels. |
| 0-4-2 |
No leading wheels, four driving wheels and two trailing wheels. |
| 0-6-0 |
No leading or trailing wheels and six driving wheels. |
| 0-6-2 |
No leading wheels, six driving wheels and two trailing wheels. |
| 2-2-2 |
Two leading, two driving and two trailing wheels. |
| 2-4-0 |
Two leading, four driving and no trailing wheels. |
| 2-6-0 |
Two leading, six driving and no trailing wheels. |
| 2-6-2 |
Two leading, six driving and six trailing wheels |
| 2-8-0 |
Two leading, eight driving and no trailing wheels. |
| 2-8-2 |
Two leading, eight driving and two trailing wheels. |
| 4-2-2 |
Four leading, two driving and two trailing wheels. |
| 4-4-0 |
Four leading, four driving and no trailing wheels. |
| 4-4-2 |
Four leading, four driving and two trailing wheels. |
| 4-4-4 |
Four leading, four driving and four trailing wheels. |
| 4-6-0 |
Four leading, six driving and no trailing wheels. |
| 4-6-2 |
Four leading, six driving and two trailing wheels. |
| Term |
Description |
| 1Co-Co1 |
1 leading axle, three independently powered axles per bogie. |
| A1A-A1A |
1 powered axle, one carrying axle and one powered axle per bogie. |
| B-B |
Two joined powered axles per bogie. |
Bo-Bo |
Two independently powered axles per bogie. |
| Bo-Bo-Bo |
Two independently powered axles per bogie, three bogies (Eurotunnel shuttle locomotives). |
| Bo+Bo |
Two independently powered axles per bogie, bogies coupled. |
| C-C |
Three independently powered axles per bogie. |
Co-Bo |
Three independently powered axles on one bogie, three on the other. |
| Co-Co |
Three independently powered axles per bogie. |
