I think we're all over those tiresome tethers between the loco & tender - a necessary evil.
I found a Bachmann loco that addresses the problem in a simple, but effective fashion.
It is a Bachmann British Outline Robinson Class 04.
The link below shows the "Clip" holding the Tether.
http://www.modelrailforum.com/reviews/Bachmann-Robinson-Class-04/IMG_2654-1.JPG
Merry Christmas to all.
Cheers.
Mark