An increase in capacity creates space for the new Class 31 (rebuilt from a mazrot chassis but a story for another time), and other locomotives allocated to the recently introduced Gosport to Sheffield parcels service.
It also allows the addition of another electric locomotive on the Woodhead Line to Manchester.
A picture of the new track arrangement is below. The new Class 31 is in the centre road of the diesel shed and the Heljan EM2 is in the short electrified siding.