train from madrid to Barcelona

I don't think there is a night train on that run. Not long enough.

I just did a quick check of the route from Madrid to Barcelona. It was almost all AVE all the way. The trains left at about 1 hour intervals and took about 3 hours. Except, there was one train that left at 21:45 and arrived at 07:05, taking 9 hours and 20 minutes. It doesn't sound like a very pleasant trip because it stops about 10 times along the way. I can't imagine that you would get any sleep on it. Check it out yourself at DB Bahn. We went the other direction on the AVE a few years ago. I took a picture when the speed monitor hit 300 kph. We loved it. I don't know how much cheaper it would be to sleep on the train. I did a very quick check of the Renfe website and saw more time options but there was no indication of any sleeping options other than sitting up in your chair. This Renfe page shows the Trenhotel for a better overnight experience, but it doesn't seem to go to Barcelona. If it was me, I'd take the 3 hour AVE and get a decent night's sleep in Madrid or Barcelona. I would not want to be sleeping in my seat under any circumstances, but especially not as a woman alone. Hopefully others will chime in here. We had a similar question a few days ago.

When? There is no doubt there is a night train. There is also a slow daytime train taking 9 odd hours for about the same cheapness. I see fares still available for some AVE day time journeys, two weeks hence, which cost €10 more than the night. 'Sleep on train' - have you had other experiences? You will be a very tired 'little old lady' curtailing her site seeing, if not. 'Safety' ?!
:-) are you worth kidnapping?

I agree with Lo: If it was me, I'd take the 3 hour AVE and get a decent night's sleep in Madrid or Barcelona. I would not want to be sleeping in my seat under any circumstances, but especially not as a woman alone. Hopefully others will chime in here. We had a similar question a few days ago.

Nancy, I just travelled that route a few weeks ago, and definitely agree with Lo and the others. Take the high speed AVE train (which travels at 300 kmH) and get a good nights sleep in Barcelona. One other thing to keep in mind is that you'll have to pay a Couchette fee for sleeping on the train, so you likely won't save any money with that route. You could find yourself in a crowded compartment with five strangers (one or more who could be snoring like a gorilla) so it won't be the most pleasant or restful journey. Happy travels!

Thank you all for your speedy and thoughtful input. I'm lucky in that I can sleep anywhere, even sitting up on a train,...but perhaps not if I'm keeping an eye on my belongings. So I'll take your suggestions, take the AVE, and sleep well in Barcelona. Moltes gracies!