Would be really cool if you could load a shipping container to the wagon.

The concept I have in mind is a vehicle entity with no features other then similar storage capacity to a Cargo wagon.
This way it can be interacted with like a normal vehicle except it has to be transported by dropping it on belts and it acts a moveable storage container.

If the contents of the shipping container could be read from the train like a cargo wagon then in theory you could bulk load/unload trains and would very nicely compliment a mod like LTN and drastically improve the efficeny of any train network.

Shipping containers:
https://mods.factorio.com/mod/wide-steel-chests
https://mods.factorio.com/mod/wide-containers-assets/dependencies?direction=in&sort=idx&filter=all

LTN Refrence:
https://mods.factorio.com/mod/LogisticTrainNetwork?from=search

This is the exact reason I made loading ramps and the Shipping Containers mod! https://mods.factorio.com/mod/shipping-containers I'd love to see your creations.

Loving the shipping containers so far, not implementing them outside of a test sandbox until I feel it's more stable.

The only thing that's missing to make this work super well is being able to read the contents of the shipping containers from the trains stops and the loading bay/ramp.
(This is because most train networks work by reading the contents of the train and the contents of the storage at the train stop to generate a provider and requester network, work this detail out and you'll make your shipping container system really popular with railway enthusiasts like myself.)

Would also be nice if the shipping containers were rectangular instead of square like standard shipping containers are IRL.
(Understandably that introduces the extra hassle of having to rotate the shipping containers sometimes to make them fit though things which could be a fun challenge with the right tools.)

Went on a tangent that resulted in some fantastic ideas here:
I was playing with it and cargo ships at one point and wondered if the Railway code could be canabalised to create a Shipping container rail system that can only be built ontop of a belt? (that determines the speed of the shipping container.)

Alternatively you could introduce a Vehicle styled rail system that can only be placed on paved ground and load the shipping containers from trains onto semi-trucks with trailers, you could also make the signals look like traffic lights because they would function the same way. (get this to work with LTN the same way Cargo ships does and you have a pretty popular mod!)

Edit:
Proposed the idea to Cargo ships as they have the resources to make that mod a reality.
https://mods.factorio.com/mod/cargo-ships/discussion/68504b7eefd077485e49b4d8