Take a 28-inch suitcase by train, which can be put on the luggage rack, but the side will leak a little. It can't be placed under the hard seat, but it can be placed under the hard sleeper and next to the seat.

Generally speaking, the length, width and height of a 28-inch suitcase are 70cm*46cm*3 1cm, and the sum of the length, width and height is 147cm, which is less than 160cm stipulated by the railway, so the 28-inch suitcase can get on the train.

Extended data:

Provisions for passengers to carry articles free of charge:

The weight and volume of articles carried by each passenger free of charge are: children (including free children) 10 kg, 35 kg for diplomats and 20 kg for other passengers. The sum of the overall dimensions of each article is not more than 160cm, and the rod-shaped article is not more than 200cm, but it is not more than130 cm when riding the EMU train; The weight does not exceed 20 kilograms. Folding wheelchairs for the disabled are not within the above scope.

References:

12306 official website-How many items can passengers carry for free?