If you're unsure which of the three women might be more receptive, you can use the 60 year old man as a pivot.
This way, you don't approach the 'un or less receptive girl' and then have to do "clean up on isle three" in order to make the other girls feel special.
Engage the man in conversation and then subtlety look at the body language of the women. Next topic, make it a question. Then, invite the other women in on the conversation.
After you have a better gauge on the more interested woman, direct your conversation to her.
Good advice.
(Probably the last) update:
The most attractive one was the one that left, another one is typing furiously on a laptop like a business woman, while the last seems quite entitled for a really young one(18-20).
In retrospect, the more attractive one lived 5 hours away from me so it's not really an option.
Now I wasn't planning on everything and these were probably not the right women for me, but still, when you have a chance, take it!
I still feel like I should have done something. Better to get a rejection than uncertainty.
Any other ideas to isolate one for the future? I don't really travel by train.