Hello and welcome to rail.cc
First I apologize the late reply. Just came back from a trip to Asia these days.
There are two stations which are relevant for Phan Thiet rail.cc/en/phan-thiet/c
1) The station directly in Phan Thiet rail.cc/en/phan-thiet/phan-thiet-railway-station/l6607
. From here you only have connections to Ho Chi Minh City.
2) The one outside of the city on the main line from the South to the North. It is called "Mương Mán" or as well "Bình Thuận": rail.cc/en/muong-man/binh-thuan-railway-station/l6606
. As short name in booking engines have a look on "MMA Binh Thuan" as departure station, then you find the direct trains on the route Ho Chi Minh City to Hanoi.
Next step is to book your ticket. Everyone will offer to do it for you in the place you stay in Vietnam. Usually it is no problem, but I personally always went to the station and bought it there directly. Or used 12go.asia rail.shop/12goasia
- select here "Phan Thiet" to "Hanoi" - in the schedules shown it says then "MMA Binh Thuan" (see explanation above). OR: use this direct link... it seems to be a bit complicate to find the right departure station - railcc.12go.asia/en/travel/phan-thiet/hanoi
The journey is about 30 hours. I recommend to take your own water and food with you. You can buy inside of the train, but it is okay - not bad - not good...
If this journey feels too long for you, I recommend stops in:
- Da Nang rail.cc/en/da-nang/c
- there you get by taxi to Hoi An rail.cc/en/hoi-an/c
which is a nice city, good to stay for two nights.
- Hue rail.cc/en/hue/c
- also nice for one night and to visit the palace.
That's also the most scenic part of the route between Da Nang and Hue (at least my personal view). Travel it by day light and remember it gets dark quiet early in Vietnam.
In Hanoi you can also continue by train to Sapa. Here is the blog post with details: blog.rail.cc/hanoi-sapa-train/
In Vietnam I definitely recommend to travel this route by train. Much more comfortable than by bus. The compartments are for 4 persons, the toilets clean, the staff friendly - even not all speak English, it is easy to "communicate". Also on the sleeper trains you have at least one person at the door who will help you get your luggage in the train.
All in all the situations on the platforms are relaxed and friendly. I see no problem for senior travellers at all. Have a look here rail.cc/en/hanoi/hanoi-railway-station/l6629
- there I have one photo how it looks like to enter the sleeper train (the photo where the friendly young man stands in front of the train door).
I will publish a blog soon about the Hanoi to Ho Chi Minh City route...
If you have further questions, please let me know. I'm happy to help you!