Node:Feeder Service, Next:Go To Depot, Previous:Load Entry in the Disk Menu, Up:The Patches
This switch allows you to operate a feeder service, that is a service which transports cargo from one station to another, where it is not delivered but rather left for another carrier. An example would be a bus that transports passengers from the city to an airport, where they are then picked up and transported to a different city by a plane.
To make use of this switch, you have to select the "unload" option in the first carrier's orders, which will force it to not deliver its cargo but rather add it to the station's cargo list. This works with as many carriers in a chain as you would like.
In addition, this patch improves how carrier profit is calculated. Normally, all carriers in such a chain contribute to the revenue, but only the final carrier gets credited with positive profit, all others get negative profit through their running costs. With this patch, all carriers get appropriate profit depending on how fast and how far they transport cargo.
This also works with a chain of more than two carriers, although in that case the final carriers get less and less of their fair share of the profit, because the cargo is on its way for a longer time, leading to smaller profit.
Note that only the very last carrier in a chain will actually generate income. Only a successful delivery will give you money, the profits in-between are only for accounting purposes, they do not actually contribute to your bottom line. The main reason for this profit calculation is the company performance ratings, which take into account the carrier with the least profit. If you have feeder services without this patch, that will of course mean the least profit of all but the last carriers in the chain is negative, even though every carrier actually does help generate revenue.
If you temporarily take over another company using the subsidiary management or Cht: PlayerID, the feeder service option is only active in your original company, and not in the computer company you're managing temporarily. The reason for this is that computer players turn on the "Unload" option in almost all of their services, which means they would all be considered feeder services and not earn any money.