Are two year old Thomas series engines doc equipped?

I am new to trains.  My grandson has been a train freak since he was two and still is at seven.  I want to make a nice setup for him.  I have a 4 x  8 table with three runs four switches.  I've just assembled it and it won't run.  The switches work, but the train won't run.  We've run it on  a single circle, but now, with the extra loops I can't get it to go.  I've learned quite a bit in the last few months trying to get this ready for him, but I am way short of knowing enough and would really appreciate some help.  Thanks.  Lkrotzer

ps: We have Thomas and Douglas and ez track and switches.