Construction of the Tyne bridge started in 1925 and opened in 1928 so tugs are probably then owned by Lawson Batey Tugs Ltd, from the rigging the bow tug 'looks like' Nestor' and the aft paddle tug by her markings possibly Cruiser
I'm with you George. Nine spokes on the paddle box, two towing bars down aft and heavy casing behind the paddles. Good match for COMET. Maybe NESTOR for the fwd tug, but not much to go on.