Amatsubame (meaning "swift") is a train. But not just any train, it is a carrier of civilization. It is designed to be sent from cities into the wilderness, opening opportunities for trade, culture, or invasion if necessary.

The train consists of three carriages (with additional designs having received State funding): a clearer/layer carriage, and engine carriage, and a defense carriage.
The front carriage is the clearer/layer carriage. It contains the pilot's cabin, large saws for cutting down trees, a processing plant for defoliating and burning wood, storage for tracks, and a system to lay tracks.
The middle carriage is the engine. A revolutionary steam-powered engine designed to work from the charcoal fed from the front carriage.
The rear carriage is a mobile defense tower which holds a high-powered crossbow (doesn't require gunpowder, much more renewable), troop storage, and a battering ram.

The entire train is designed to be largely self-sufficient, the only additional support it requires is track refiling, but a mining and forging carriage is under development but the National Science and Technology League.

Don't forget to diamond!