66544 accelerates up to line speed leading the 4M81 Felixstowe to Crewe Freightliner at Marholm just north of Peterborough. This 4M81 Freightliner has been known to travel via the WCML at times depending, it seems, on the availability of electric traction. Notice 91106 bearing down on the freight leading the 10.33 King's Cross to Leeds LNER service of which there is a better photograph coming next in this sequence, see......
https://www.ontheupfast.com/p/21936chg/30023305716/x9-91106-gr-10-33-london-king-s-cross