How often are these long couples in service?

Quote (Zxs91, 23.05.2025):
> How often are these long couples in service?

Nowadays only very rarely, for most events on the fairgrounds triple units in a 5 minute interval are deemed enough. The highest chance to see some of these 4-unit trains would most likely be on Sundays with big events - like with this picture, taken on the day of a big concert by the band AC/DC.

Thank you!