I have a small layout for running both the conventional 12v system and the Hornby live steam. There are four sections on which I can run either type of loco. I switch each section over between the live steam 'bus-bars' (virtually the same as those needed by DCC) and the conventional system using double-pole relays. Sections are completely isolated from each other by insulated joiners. This ensures the two systems cannot be accidently connected together. You could connect every section like this and link all the relays together to one switch to select which you need.
More information is in the 'O,G and larger scales, Live Steam' forum on the second page in the thread 'Mixing Hornby live steam with 'trad' 12volt'.
Regards,
John Webb
More information is in the 'O,G and larger scales, Live Steam' forum on the second page in the thread 'Mixing Hornby live steam with 'trad' 12volt'.
Regards,
John Webb