That's encouraging, jremington, I guess the next step is to select the Arduinos and Communications Modules.
At the moment it's the communications modules that have me in a dilemma. I initially thought of a MEGA master (onboard the carriage, where most of the detail exists) and a UNO slave on the ground. For communications I was thinking of the ESP8266 Mini because that leaves the I/O ports free for the Arduino to run the mechanics. In shopping around (here in Perth, Western Australia) the Mini seems to have been replaced (certainly in availability) by the ESP13 Shield which appears to take up all the ports on a UNO. I get the impression that the UNO would be able to communicate with the internet through the shield but not be able to control anything nearby. I think that the MEGA would have the same problem with the shield.
Can you clarify this for me, or would you please point me in the direction of some tutorial material which will.
Please remember that this is all first impressions stuff and that I am just groping around in the dark.
Thanks