Cargo wagon

The cargo wagon is a train car item used for bulk item transport and as a large static storage block when placed on rails. A single cargo wagon holds 40 inventory slots. For many raw ores each inventory slot stacks to allow a total of 2000 items (for example copper ore or iron ore). For common processed plates each slot stacks higher, allowing a total of 4000 items (for example copper plates or iron plates). Because some raw materials compress into fewer processed items, preprocessing near resource sites can increase effective train throughput; for example, five iron plates craft into one steel plate, so transporting steel plates instead of iron plates increases transported throughput by a factor of five for that conversion.

A cargo wagon can be used in two primary ways: as part of a moving train for long-distance logistics, and as a stationary, large-capacity container by placing it on rails and keeping it unmoved. When used as a static container, inserters can load and unload the wagon along its whole length. That allows many inserters to operate on the wagon simultaneously and bypasses the practical limits imposed by inserter stack-size behavior on chests. Items placed into or removed from a cargo wagon are moved instantly across the wagon’s length, which can be faster than a transport belt over equivalent distances if set up correctly. The wagon inventory supports item filtering and limited inventory sizes via direct inserter control.

Limitations of the cargo wagon when used as a static chest include inability to connect directly to the circuit network, inability to be accessed by logistic robots, and smaller total slot capacity than a steel chest. The cargo wagon’s contents can be read by the circuit network only when the wagon is part of a train that is stopped at a station; even then, different wagons in the same train cannot be distinguished by the station readout. A steel chest offers 48 slots compared with the cargo wagon’s 40 slots, independent of quality or upgrades.

Practical notes and common considerations:

• Use preprocessing (smelting, plate production) near mines when stack-size differences or crafting compressions increase effective transported throughput.
• Use an unmoving cargo wagon with multiple inserters for high-throughput staging where belts would be slow or where many feeders are needed.
• Do not expect circuit connection or robot access when the wagon is used purely as a static container; plan station-based readouts if circuit monitoring is required.
• Compare total storage and slot counts against steel chests when choosing storage: cargo wagon offers mobility and line-wide inserter access but fewer slots than a steel chest.
• When designing train logistics, remember wagon stack capacities vary by item type, so calculate train load and unloading speeds according to the actual items carried.