ECML Down Fast slow running between Brookmans Park and Welham Green

[Potterlad]

I've noticed that for the last couple of days all of the trains on the ECML down fast line between Brookmans Park and Welham Green seem to be running at a much reduce speed compared to normal. Does anyone know what the problem is please? I can't see any TSR boards about, but they may be around the corner where I can't see them. The up fast seems to be unaffected by whatever the issue is.

I think that there was issue a few days ago and some (most?) down fast trains were being switched to the down slow at Potters Bar, through to Welwyn Garden City but is the slow running over the past couple of days related to that or something different?

Thanks.

 

[OxtedL]

There's a 50 TSR board just north of Brookmans Park

The Down Slow has had a TSR on it for a couple of weeks already.