I’ve noticed this in the Napa yard last month:

First time I noticed was on 2019-10-12 and that was definitely new.

It reminds me of the Earthquake Trail at Point Reyes, yet I am sure we are not modeling the San Andreas Fault here. And viewed from the other side, it isn’t any better:

Today I noticed it also happened in the Richmond yard to a lesser extent:

Why? Not a clue. There are forums filled with posts of folks to which such “track warping” has happened, and typically it is attributed to either heat expansion or drastic dry/humidity changes. That’s a bit odd since we did not have any such drastic weather changes recently, at least not more than other years, and that track/workbench has been around for several decades.

There is no sign of water damage, which is the typical question I get next. We had ground-level water flooding last year during the rainy season and it did not affect the yard at all.

One difference is that the track at this location is not held in place by ballast like the rest of the layout.

In Napa, the end of the each yard track is solidly anchored using a large nail holding a piece of foam. The roadbed is made of homasote or similar. The other side is the yard turnout ladder, and by the way, one of the rails has warped enough in one of the turnouts that the gauge is obviously wrong and the inside of the rail is missing the little plastic tabs that hold it in place:

The track does not appear glued there. Instead the flex track is merely nailed every foot or so. I guess we’ll have to remove the nails and rework it straight starting at the turnout for each yard track in the ladder. I should also bring my HO track gauge and check the track. I’d suggest fixing the track using liquid nails or a similar product when we reinstall it.

Luckily this has not happened anywhere else on the layout that I could notice, but maybe I should try to do a full survey of the layout using a cab ride camera.

Update: "2019-11-07 - Follow up on Warped Track Maintenance".