I took these pictures of a German-designed ten-wheeler on a preservation line in Bavaria in 2012, and since have wondered what’s the purpose of the red-painted component projecting down from the frame in which the Walschaert valve gear link is pivoted.

As the second view shows, it comprises a pair of curved bars, one inside and one outside the main rod, fastened at their bottom ends to a cylindrical spacer.



I’ve noticed this feature on German locomotives of various wheel arrangements, usually with the bars straight instead of curved.

After reading the report of the Tangmere incident, I thought maybe it’s a “rod catcher” intended to keep the front end of the main rod from digging into the ballast or ties in case the crosshead pin comes out. But it looks WAY too flimsy to withstand the wallop of a falling main rod.

It doesn’t appear to be oriented properly to help a fireman or engineer step up to reach an oiling point.

Anyone know the purpose?

Judging by the looks of it, I would have to agree with your first guess, a safety catch for the main rod. It doesn't look to be exceptionally stout but it only has to contain the rod long enough to get the train stopped. I wonder if there is any record of one being tested.

From what I have seen in Germany and Poland the devices purpose is to ease in the removal and installation of the main rod. It acts as both a pivot and a roller. Way too flimsy to catch one in motion.

It is indeed a rod catcher after breaking or bolt loss. It prevents the rod from sticking into the track bed while driving.
Kind regards
Jos Koopmans

Something to remember, its not how big or wide a piece is, its how it was forged. The proper process can yield a very strong part even if it doesn't necessarily look so, and I suspect that this is the case with this part.

Thank you for the replies.