A railway is not a fleet of trains; it is a fleet tied to places. Every train you own begins and ends its day at a depot, every line has to touch one, and every depot needs people on the ground to run the departures you schedule from it.
That is what stops a railway growing in a straight line. Trains can be bought in an afternoon. The ability to operate them has to be built.
A depot is a station where you have a presence: trains can be stationed there and lines can start there. Your first depot is chosen when you found the railway, and it is also your headquarters.
Depots have levels. A higher level carries more of everything — more trains, more departures, more staff — and each level costs more than the last. Levelling a depot is one of the few purchases in the game that never expires and never wears out.
One depot is your HQ, and it carries more than the others do at the same level. That is not a bonus for its own sake: it means the shape of your network matters. A railway built around one strong home is a different company to one spread thinly across four cities, and the game should let you feel the difference rather than reading it in a table.
You can move the headquarters. It takes time — the move is not instant, and while it is in progress you are running a railway whose centre of gravity is somewhere between two stations. That delay is what makes moving a decision rather than a free optimisation. If your network has genuinely outgrown its origin, move; if you are chasing a small advantage, the transition will cost more than the advantage is worth.
Every departure needs people behind it: platform staff, dispatchers, planners, the ones who rebook a passenger when a train fails. The game models this as a load on the depot the departure leaves from.
The load is not per train. It is per departure, plus an amount that grows with the length of the journey, plus a surcharge when the line crosses a border. Two consequences follow, and both are intentional:
Each depot has a capacity that grows with its level, and the HQ carries more than a regular depot of the same level.
Going over capacity does not stop anything. Your trains keep running and your passengers never find out. What happens instead is that you pay overtime, every week, for every point of load above what the depot can carry.
This is on purpose. A hard ceiling would turn depot levels into a gate you unlock; a running cost turns them into a judgement. Overtime for a few weeks while you save for the next level is a perfectly reasonable way to run a railway. Overtime forever is a slow leak that a growing railway stops noticing, which is exactly how real companies end up paying for it.
The upgrade pays for itself against the overtime it prevents, eventually. Whether "eventually" is soon enough depends on how hard you are running the depot — which is the decision the mechanic exists to create.
See also Fleet, Facilities and Lines and operations.
Start your railway