Factorio Forums

Is there a good way to allow multiple trains running at once on the same stretch of (one-way) track without collisions? My best guess is that you'd want to divide it into blocks exactly long enough for a train to brake from top speed to stationary. I'm not sure it would work with chain signals, though. I haven't used them much yet. Has anyone done the math on this, or tried it?

The best way to signal a one-way track with no intersections is to put a normal signal on every tile. Trains will automatically reserve all the signals they need for braking.

Of course, signals on every tile is rather extreme. You can space them much more than that, and the spacing errors only reduce track usage efficiency by a tiny bit.

I would add that you may need to parallelize acceleration for larger trains (especially those with lower ratio of locomotive to wagon).

On my final 0.14 base, I played around a lot with "compression" of a rail line. I was able to achieve ~20 trains per minute with 1-2 (LCC) trains (~80k ore per second) on a single track (which is fairly close to the theroetical max of just over 21 trains per minute) using a normal RORO unloading setup (parallel unloading stations), rail signals spaced every 15 tiles on long stretches) and no left turns.

When I tested longer trains with lower ratios of locos to wagons, I found that I couldn't get higher than ~25% compression without having multiple acceleration tracks and even that wasn't a perfect system because if two trains reached the main-line merge at around the same time, then one would come to a complete stop (and acceleration is slow for trains with low ratios of locos to wagons). The highest throughput I've gotten in-game on a single piece of rail over a period of a few hours is ~2 wagons per second using trains of size 4-20 (a coincidence ), which is only only 50% compression. I had to abandon the save because my UPS was down to ~3.

P.S. You mentioned collisions - if you have atleast one signal (of any kind) on a rail network. Then it ensures that trains in automatic mode will not collide (barring a bug which happens in bases with very large # of trains) assuming you don't set two trains to automatic mode whilst in the same block.

Thanks, guys! I guess the signal system is more robust than I realized. I usually run large power poles with adjacent lights down the center of my rail lines, so I might just add a signal on either side at the same interval.