We will be going from rome to naples. we want to go on the fast trains, es, or artesia. We are not sure however when we will get to termini. How far in advance do these trains need to be booked. We are going mid week, not on a holiday,so I'm sure there will be space on the train.Is it possible to book it on the ticket machines 2-3 hours before the train leaves.

Yes, that should be possible. (Don't know how to make the "should' bold!) Or, if you are staying in an area in Rome where you spot a travel agent with the Trenitalia logo in the window, book your tickets there, with no extra cost.

Thanks. We will be taking a train from Orvieto to rome. I don't know if we will be able to drop off our car early enough to catch the train we would like to be on. If we can't we will arrive in termini an hour after the train we would like to take to naples.

For Rome/Naples it's ES or AV (not Artesia which goes to Paris) for the fast trains which leave Rome hourly so you shouldn't have to hang out 2-3 hours in the train station. Yes, you can use the ticket machines and book right before departure. There are rows of them in Termini out by the ticket windows (not track side). There are a few machines track side that were cash only (or at least the ones I saw) so you will probably want to use the others that accept credit cards. If you are dropping a car in Orvieto, they probably don't open until 9 or 10.

If you are spending the night in Orvieto, you might want to drop your car the day before you depart for Rome. Then you would be able to depart Orvieto as early as you want. Last year someone in my hotel was taking the earliest train (4:30am) to catch a flight out of FCO.

Then, as you have no doubt already worked out, if you can do as kybourbon suggests, you can buy the ticket from Orvieto to Naples, for the time that suits you.

Thanks

I'm confused: why don't you take a direct train from Orvieto to Naples, thereby avoiding a change in Roma Termini?

The direct Intercity trains from Orvieto to Naples will cost much less than taking the AV or ES-Fast train to Naples out of Roma Termini, and you won't save much more time by doing a connection in Rome.

Seats on the IC direct trains are automatically reserved upon ticket purchase, so you won't have any issue in that regard.

If I have misunderstood your posting, and you are breaking your journey in Rome, you can still save money by avoiding the AV and ES-Fast trains between Rome and Naples, and opting instead for the cheaper (but nearly as fast) IC or "regular" ES trains.

Look up the Trenitalia schedule and you'll see what I mean:

www.ferroviedellostato.it

GAC - Most trains from Orvieto to Naples require a change in Rome. He is wanting to leave early and the only IC train without a change in Rome is not until afternoon.

He could take the 9:05 regionale train to Roma Termini, then connect to the 11:28 IC "Archimede" to Naples.

Otherwise, he might as well take the direct 12:09 IC "Brera" from Orvieto to Naples (without a need to connect at Roma Termini).

By departing at 9:05, he gets into Naples 2 hr. and 20 mins. sooner than if he waits for the direct train at 12:09.

I'm really not so sure it's worth the trouble of an earlier departure and a connection in Rome.

There are still earlier trains from Orvieto to Rome (with connections to Naples), if that is his preference.