The tests were undertaken to establish the following:
 | The price in terms of coal and water of hauling different train loads and different speeds over given routes |
| An indication of the level of efficiency of the locomotive |
| Means of comparing one locomotive with another on a common basis |
Testing was undertaken on the static test plant at Swindon and on the line between Challow and Stoke Gifford (Bristol Parkway), a distance of approx 50 miles.
Here is a summary of the tests and a few pictures.
Pictures are BR official
