I wrote this as a new post before I found this thread - posting here to preserve my point of view.
After reading some of these comments I also like the idea of allowing locomotives facing any direction to provide full power, but otherwise work as things do now (i.e. one locomotive must be facing the direction of travel). Compatable with all existing setups, and no lugging dead weight around.
Currently, locomotives in trains have a driving direction. In manual mode they can be reversed, but when running automatically, they can only go forwards.
This leads to making a choice between eiter using single-direction trains, or pulling dead-weight locomotives around on bi-directional trains.
In reality, real locomotives can run just as well in either direction. However, trains wouldn't run (other than slow shunting manovures) without a locomitive at the forward end.
How about changing Factorio locomotives to work like this?
- Locomotives provide power running in either direction
- Trains need a locomotive at the front to run in automatiuc mode. Locomotive direction is uninportant
Some examples, to help exploain this:
In automatic mode
The top track: both trains can run with the same power - the left one is bi-directional, the right one is single direction only
The middle track: Plain locomotives, just one or a pair, can run in either direction.
The bottom track: The locomotive can't see where it's going, so cannot run in automatic mode in either direction.
: rather than locomotives in reverse running but in reduced speed, trains without a locomotive at the front (in the direction of travel) run at reduced speed.
Additionally, rather than completely banning trains from running without a locomotive at it's front, there could be an option in the train timetable to specity a timetable entry as a shunt manovure. Trains cold then run in reverse, without a locomotive at the front, but at a vastly reduced speed. This would be handy for a mainly one-direction train network where the occasional station needs a train to reverse out of a station, shunting into a separate reversing siding.