Steel Mill Train (SA22) runs north out of the yard late afternoon / early evening five days a week. I've heard it runs Sun mornings too.
Sometimes you can see it around 5 - 6 pm ready to leave the yard or see it getting assembled in the yard.
Lately, I haven't seen this when passing by at 5 - 6 pm. so I'm thinking SA22 could be running earlier or later.
If you have an afternoon free OI16 comes in from east M - F at 5 - 5:30 ish.
SA33 departs west M - F at 5:30 - 6ish pm.
Sometimes you can see SA33 waiting to leave west end of yard.
You can try catching OI16 first, then SA33 second, all the while keeping an ear open to hear SA22 crossing Bordentown Rd.
my experience is that SA22's run time is most variable, while OI16 is least variable.