There are usually 4 hard-seat cars in each Tibet train, each car has around 98 seats, totally acccommodate 392 passengers. The shortest ride of Tibet train is from Xian/ Xining/Lanzhou to Tibet or reverse, but even these shortest rides will be over 24 hours, let alone those longer ride ones from Bejing, Shanghai, Chengdu, Guangzhou and Chongqing. So we do not recommend visitors to take the hard seats if possible, you may choose the soft sleepers or at least hard sleepers for better comfortness.
The hard seats on Tibet trains are usually softer and nicer than other ordinary hard seats in mainland China. Individual oxygen outlets is equiped under the seats for passengers. When running from Golmud to Lhasa, difusion oxygen will be produced and spreading into the cars, and most passengers won’t get strong altitude sickness during the journey on the train, only 1/20 of the passengers will need to use the pipe oxgen outlet as our experience.
The train luggage limit is actually not strict as flight, above the seats, are the space for storing luggage. It will be enough space for you. (Common luggage size required).