Minecart with Chest

A minecart with chest is a minecart with a chest inside it.

Natural generation
Minecarts with chests naturally generate in abandoned mineshafts.

Crafting
Minecarts with chests cannot be retrieved by attacking them, as they just drop a minecart and a chest plus its contents. Still, they are renewable; the player can simply recraft them.

Usage
Minecarts with chests can be placed by on a rail.

Chest minecarts' contents can be accessed by pressing button on them. The interaction makes no sounds and the chest does not show the opening or closing animation, unlike regular chests.

The boost that minecarts with chests gain from powered rails is dependent on their load. For example, from a 1 powered rail starter track, an empty minecart with chest travels 64 blocks, but a full minecart with chest travels only 16 blocks (opposed to 80 blocks for an occupied normal minecart and 8 blocks for an empty normal minecart).

Another physical property of chest minecarts is their ability to be stacked. Whereas only 3 chests can fit in an area 3 blocks tall, up to 4 chest minecarts can fit in the same area.

Minecarts with chests are also able to interact with hoppers. Hoppers can take items out from the minecart chest if they are below the track as the cart rolls over it or put them in if the cart rolls under a downward facing hopper.

Data values
Minecarts with chests have entity data associated with them that contain various properties of the entity.