Thanks to those who pointed out the location of yesterdays photo. Thanks to the magic of the Alexander Turnball library and Whites aviation I have found this (or don't, this one is dead)
If you enlarge the picture zeroing in on the railway line at the top center of the picture, you can see the double signal between the 2 road bridges. However on the back shunt there is no sign of a line down to the Lion crap works or the tallow works across the railway line. However this picture was taken in 1949 so there may have been something there earlier.
Over to the peanut galley for more thoughts.
UPDATE; They really don't make it easy for you do they. Try this link instead. (and don't cos its dead too).
If that fails go to Timeframes and search on 'Newmarket railway 1949', and look for the