A shipping line is not a fleet of ships; it is a fleet tied to places. Every ship you own begins and ends its rotation at one of your ports, every trade lane has to touch one, and every port office needs people ashore to run the sailings you schedule from it.
That is what stops a line growing in a straight line. Ships can be bought in an afternoon. The ability to operate them has to be built.
A port office is a harbour where you have a presence: ships can be stationed there and trade lanes can start there. Your first office is chosen when you found the company, and it is also your head office.
Offices have levels. A higher level carries more of everything — more ships, more sailings, more staff — and each level costs more than the last. Levelling an office is one of the few purchases in the game that never expires and never wears out.
One port 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 line built around one strong home port is a different company to one spread thinly across four coasts, and the game should let you feel the difference rather than reading it in a table.
You can move the head office. It takes time — the move is not instant, and while it is in progress you are running a company whose centre of gravity is somewhere between two harbours. 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 sailing needs people behind it: agents, planners, stevedore coordination, the ones who rebook a consignment when a ship goes technical. The game models this as a load on the port the sailing leaves from.
The load is not per ship. It is per sailing, plus an amount that grows with the length of the voyage, plus a surcharge when the voyage crosses a border. Two consequences follow, and both are intentional:
Each office has a capacity that grows with its level, and the head office carries more than a regular office of the same level.
Going over capacity does not stop anything. Your ships keep sailing and your customers never find out. What happens instead is that you pay overtime, every week, for every point of load above what the office can carry.
This is on purpose. A hard ceiling would turn office 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 shipping line. Overtime forever is a slow leak that a growing company 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 port — which is the decision the mechanic exists to create.
See also Fleet, Facilities and Trade lanes and operations.
Start your shipping line