During my previous visits to India they made train reservation by phone. Now it is all computerized so if you arrive here you can book all your rail journeys from one big station. It will give you the advantage not to worry about free seatts or berths.
I took 15-hours rail journey from Goa to Cochin… It was a/c 2nd class carriage. It was more safe there then in non-a/c class (and you have more privacy there) but I got cold and I am sneezing now… in the temperature of 40 deg. Celsius.
We arrived to Cochin -Ernakulam station at 2 pm. Then I took a sweaty 20 min walk to the jetty. Ferry took me to the old part of the town – Fort Cochin located on the peninsula. I found accommodation in Old Adam’s Inn in one of this enchanting narrow streets. They charge 350 rp per single room with bath. Nice place, but bring your mosquito net with you! You will find only little, dirty beach here but Fort Cochin has still lovely, colonial atmosphere…