Is the drawbar a replacement for the tether cord between loco and tender?? They are areal pain - the tethers that is!
Yes and no??!!
By that, I mean yes, they wanted to get away from the tether so at some point a major design change happened and engines after that production date are designed with wireless PCB drawbar systems. Again, this design is integral to the chassis and is signifcantly different so you are not going to just buy some kit and retrofit an engine with a tether.
Both systems have drawbacks.
Chief issue with the drawbar system is the connectors at both ends and just general pulling stress on the drawbar system.