Thank you Volts, Jopie and Spock. (The internet can be a great place )
Ok..
So I just googled "Lipo lego" and having tried to read this http://www.eurobricks.com I suddenly realise just how much out of my depth I am.
Glueing rails to "ties" (whatever they are ) .
Steep learning curve I guess...
But I really appreciate your time.
..and you Travis!