How can I get my ship to go back to the dock once it's full, even if it has other oil rigs to go to?

Question

I have some ships going to multiple oil rigs because each rig doesn't generate a lot of oil. However, sometimes it gets full after the 2nd, 3rd or however many rigs, and wastes time fulfilling the rest of the orders (it's full and can't unload) until it gets to the dock. Is there any way to give this boat an order to go back to the dock once it's full? (For example, below, if ship 2 fills up at Slunthill South, it would just go straight to Gondinghall Docks skipping the 2 stops in between.)

I guess I could have it transfer but I'm not sure how efficient that is.

Answer 1

The way I usually do this is, after every "Go to place" order add a "Conditional order jump" with something like "If 80% full Go to Order 1".

When the ship is done with loading somewhere it will check that order, and if nearly full it will go back to the first order (change the numbers if this is undesirable). The downside to this is that the last stations will be visited less often than the first ones.

Its also possible to to the reverse, after every "Go to place" order add a conditional order with "If less than 80% full Go to Order N+3" (where N is the order number of the "Go to place", N+1 is the conditional order, etc). Then add another order to go to the depot where it has to deliver (which will be N+2) and then the order to go to the next location (making it N+3).

This will cause the ship to go to 1, 2, think "Oh I'm full, lets go drop off something" and go to the drop-off depot, continue to 3, 4 and loop back at the end of the order list.

More detail: http://wiki.openttd.org/Orders#Go_To

Answer 2

This is what I did:

1. Go to Oil Rig 1
2. Jump to 4 if Load is 'less than or equal to' 95%
3. Go to port (or transfer)
4. Go to Oil Rig 2
5. Jump to 7 if Load is 'less than or equal to' 95%
6. Go to port
7. Go to Oil Rig 3
8. Jump to 10 if Load is 'less than or equal to' 95%

9. Go to port

10. Go to Oil Rig 4 (Last oil rig, or rig closest to port)

11. Go to port

What this does is goes to an oil rig, after it loads the petroleum, it checks to see how much it has loaded. If it is less than 95% (adjust for size of oil barge) it goes to the next oil rig, but if it is 95% or more then it goes to port to unload or transfer. For the last oil rig, I do not check for load, I just instruct the oil barge to go straight to port to unload and then start the round all over again.

The one disadvantage is if, lets say that the ship leaves rig 1 at 85%, and goes to rig 2. When load reaches 100% the ship will leave whatever oil is left then go to port and continue onto oil rig 3. It will not return directly to oil rig 2 it will just continue to oil rig 3 and so on... This is partly due to the limited logic choices of the game.