Parece haver armários de bagagem na estação de trem de Hanói. A web tem alguns traços sobre o assunto, incluindo este tópico do Tripadvisor, que cita instruções e custos (atualizado em 2013) :
Hi, there are luggage lockers available at Hanoi train station. I used them today -12 hours for about $2.
They are located at the far end of the booking office and fit my large pack easily. They lock with a key but there is space to put a padlock as well (which I did).
With some time to kill before our departure we FOUND and USED luggage LOCKERS that were found on the extreme left hand side of the facility. To get to them you must pass by the ticket purchasing area and keep on going to the end of the building. It’s not a large facility at all so you should have no issues finding these lockers.