Some news regarding electric to diesel changeover from.Network Rail:
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New square shaped, blue bordered signs are being erected at the appropriate Stop Car Marker Boards for class 755 bimodes.
A white Class 755 on a blue band tops the sign. Half of the remainder is Power Changeover (separate lines) in black lettering divided by a blue band from the bottom segment. All the latter have the yellow exclamation triangle on the LHS. The Diesel to Electric sign exhibits Electric and 25kV on separate lines to the right. The opposite changeover is topped by DIESEL in red lettering with Lowestoft beneath and Felixstowe below that in the example shown.
Locations:
Ipswich Down Pfms 2-4
Stowmarket both platforms for the different changeovers
Norwich 1-6 Up
Presumably reminder signs to pan-up/down will be provided at Ipswich/Nowrich in the opposite directions.