sorry for the “paint job” but I thought something like this would’ve worked?
blue arrow is the slow train, the red/yellow arrow is the fast train and the yellow squares are signals.
Assuming there is enough time, the fast train should be able to go onto the top section of track?
You might need to adjust the placement of the signals, am not 100% sure, but I would expect it to work.
*Edit – I broke the photo/thumbnail somehow… There should be a second “arrow” (indicating the fast train) off the right side of the pic.