List of British Rail power classifications
Wikimedia list article
The British Transport Commission, later British Railways, used engine power output to categorise its new main line diesel locomotive fleet following the 1955 modernisation plan. These categories were from Type 1 to Type 5 and are listed below.
Type 1 change
Up to 1,000 bhp
Type 2 change
From 1,001 bhp to 1,499 bhp
Type 3 change
From 1,500 bhp to 1,999 bhp
Type 4 change
From 2,000 bhp to 2,999 bhp
Type 5 change
From 3,000 bhp