Large Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 7
Distraction; Human-Machine Interface; Situational Awareness; Workload
ATC Issue All Types; Conflict Ground Conflict; Less Severe
Air Traffic Control Provided Assistance; Air Traffic Control Issued New Clearance
Human Factors; Staffing
I was working all RADAR positions combined in the Tower cab due to the COVID schedule.  We had a priority handling aircraft land at ZZZ1 which caused multiple aircraft to be placed in holding/kept in the RADAR pattern. While this was going on I had a heavy increase in traffic volume.  I based Aircraft X to a 240 heading after an extended downwind; about 15 miles out at 020 MSL. Shortly after basing the aircraft I received multiple calls from aircraft and became saturated with traffic and transmissions. I realized Aircraft X had gone through final and was headed towards a man-made obstruction with the obstruction height of 2;XXX feet. I issued a right turn to heading 050 to get them away from the obstruction. I started issuing a climb to Aircraft X when I realized I had a VFR aircraft receiving radar serve at 030 directly about him. This caused me to cancel the climb and stick with just the turn. I then tried to turn the VFR aircraft so I could climb Aircraft X but between my voice quality and the other aircraft on frequency he didn't understand my transmission. I believe Aircraft X came within 3 miles of the obstruction.I believe working on the TDW (Tower Display Workstation) display which is smaller than our normal stars displayed caused a higher complexity of traffic. I'm not really sure what could have prevented this event other than going back to normal staffing levels and working back in the RAPCON.
Tower Controller reported an aircraft missed a turn and came within less than the required separation from a tall obstruction.