First trial of the bow thrust was a bit of a let-down. The thruster worked for all of 30 seconds then the paddle slipped off the shaft.
Back home for a dab or two of epoxy!
Second trial went much better, though I discovered that I must replace the current ESC. It came with the tug and is probably one from a car - 100% power one way and about 50% the other.
Using thruster alone, the tug will turn more or less in her own length. OK, that's not new as using twin screws and Becker rudders, she turns on the spot anyway. However, it was interesting to see what could be done with the thruster in combination with screws and rudder. I couldn't get her to crab sideways but diagonal movement is possible. I think a bit of practice is required here!
Going astern with many models seems to be hit and miss, but I found that it was possible to go astern and correct any swings with a quick blast of the thruster.
When towing something heavy, or when acting as stern tug (towing over the stern), using the thruster is a useful way of swinging the tug's bow without changing the amount of pulling/braking force. OK, this could be done with rudder, but just a quick burst on the thrust produce the result quickly.
And of course, it's nice to apply a quick burst of thrust to move the bow away from the quay when leaving 'harbour', or as a gentle nudge alongside.
All in all, I'm well pleased. For relatively little outlay (approx £30 for the thruster, £5 for filler (tons left) and a few quid for sundries like wire and glue, it's added a new dimension to the tug. Well worth the money and time spent, iMHO.
Thanks to those who have supplied info and help in getting it installed.
Andy