.17.23 Random trains suddenly slow

[RexBuck]

Started noticing this yesterday in .17.22 and the phenomina continues on with the upgrade.

Every once in awhile a train will suddenly slow and appears to never speed up again. All of my trains are configured the same so, when I started to notice the odd train slowly plodding along with a bunch of the same size trains stacked up behind it, I knew there was a problem. The first two were 6-3 trains. The only way I could get them back up to speed was to deconstruct the 3 engines on each train and rebuild them with all their components. Now I notice my supply train 4-2 is running slow as is one of the haul trains 8-4. There may be more and I just have not noticed them yet.

Game and Mods here: https://www.dropbox.com/sh/dy2rb6hqvu89 ... 2ZHca?dl=0

[Rseding91]

Thanks for the report. I took a look at your save and the reason your trains are running slow is they're modded to be heavy and have poor braking power which means they have to slow down to prevent hitting the train in front of them as the one in front slows for the one in front ... repeat until you get to the first train in the set of trains.

You can watch this happen as the front most train gets a clear path it accelerates rapidly along the rails to its destination.

[RexBuck]

Thanks for your reply. What I have observed is the train in the front of the pack is the one that has the slow condition and is holding back the rest that want to go faster. They are all built and modded the same.

As an adendum, what I am now finding is that a "slow train" will periodically speed up, only to slow again.

As an example, if you look at the game I posted, there is a group of4 8-4 trains to the left of the map (west). One of them has this slow condition and usually runs substantially slower than the other trains Watch them after they load. The slow train plods down the track after loading and by the time it reaches the halfway point to the unloading station, the other 3 have loaded and caught up with it. They are all configured the same and all fully loaded.

[RexBuck]

Just to add another dimension to this problem, in addition to some trains randomly running slow, if I put my player into a train . . . it runs slow.

[RexBuck]

Anybody? This phenomina is making the game tedious - would really appreciate figuring this out.

[DaveMcW]

Get rid of your train mod or ask the author to fix it.

[astroshak]

Braking Power affects their braking distance. The higher the speed, the longer the distance required to brake. The higher the Braking Power, the shorter the distance required to brake.

If they do not have sufficient braking power for their top speed and the traffic and their route ... their speed will be limited by the braking power. Vanilla Factorio does not seem to have this problem, though I suppose it might appear if you were using Nuclear Fuel for your trains and had not researched any braking power tech.

[RexBuck]

All of the braking power has been researched. The problem is not a general slowing of trains but a random slowing of trains. Have a group of identical trains (same size, same mods) and all of a sudden, one starts going the speed of a MK1 train. All the other identical trains then back up behind that slow train.

[Koub]

If the issue is a bad balance between the modded trains' weight and the braking power, then the issue comes from the mod. make it that the modded trains are less heavy, on make it that there are more breaking force researches (or that the researches scale better with the additional weight within the mod.

[RexBuck]

Looks like it was caused by a mod called Train Tunnels. It was activated but I wasn't using it. Game crashed (Blamed on the mod), I deactivated the mod and trains back to normal. Thanks to all respondents for their time and input.