Platform 3, T111, must be a T3 line block, that track section is under possession.
The *CUT is a puzzle, could it be "Currently Under Test" for example the S&T are testing the track, using a Dropshunt box, in such case the Signaller wouldse see his track circuit indicator for platform 1 ( incidentally a Bay platform line ) going from occupied to clear as the s&T test proceeds