[4] In 2005, Euro Cargo Rail (ECR) was formed as a freight operator in France by English, Welsh and Scottish Railway (EWS).

[5] Although these locomotives were intended for use in France, maintenance was planned to be carried out at EWS's depot at Dollands Moor, close to the Eurotunnel terminal at Cheriton.

Because the locomotives would be operating on railways in Great Britain, they were allocated numbers in the TOPS system as Class 21.

[7] In 2009, Eurotunnel's five locomotives were used extensively for rescue operations following severe snow.

[8] As a consequence, the company identified a need to have greater availability of these units, and so procured a pair of Class 6400 locomotives from DB Schenker Nederland in November 2010.