February 2013 sees the 40th anniversary of the commissioning of Sheffield Power Signal Box. The opening of this signalbox saw the end of the mechanical signalling in the Sheffield area but it did not just stop there. Over a period of time over sixty mechanical and small power signalboxes would gel into just one large PSB. To tell the story of the development of power signalling in the Sheffield control area means stepping back in time further than 1973 and looking at the smaller resignalling schemes that would eventually become part of Sheffield PSB. So, this is a look at those boxes closed just before the Sheffield resignalling scheme and those closed when Sheffield gradually took over their operation, along with views of track rationalisations and new chords and junctions.