Date: 201509
Local time of day: 1801-2400
Location: ZZZ.Tower, US
Light: Night
Aircraft: Commercial Fixed Wing
Operator: Air Carrier
Flight plan: None
Mission: Other tow
Flight phase: Taxi
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Second aircraft: Widebody; Low Wing; 4 Turbojet Eng
Reporter organization: Government
Reporter function: Ground
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Distraction; Confusion; Communication Breakdown; Situational Awareness
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway; Ground Incursion Taxiway
Detector: Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Provided Assistance
Contributing factors: Human Factors; Procedure; Airport
Primary problem: Airport

Narrative: Needed information.  Taxiway Zulu is closed to Super tugs and aircraft under tow for 3 weeks between taxiways S2; and S.  So we must cross super tugs and aircraft under tow at taxiway sierra across runway 28L. Treating the super tugs like opposite direction aircraft. The reason the super tugs can't proceed through the construction area is that the vehicle lane that the airport created is either too sharp or too narrow for them to navigate due to the size of their vehicles.Aircraft X called for re-position to [maintenance] from gate 64.  Was told to push back on Alpha.  A few minutes passed by and with 1 minute of each other; Aircraft Y called to proceed to a gate on the [company removed] side of the ramp and Aircraft X called to proceed to [maintenance].  I looked at the radar and determined that since there were no aircraft that would conflict with the runway crossings in the immediate future; I decided to take the Aircraft Y via uniform and to take the Aircraft X via delta so that they wouldn't have to wait for each other.  The Aircraft Y was instructed to proceed via Zulu; uniform hold short of runway 28R.   Aircraft X was instructed to proceed via delta and hold short of runway 28L.  Both read back correctly.  Traffic then cleared the runways and I coordinated the crossings with the local controller.Aircraft Y was instructed to cross both runways and proceed as requested once across and complied with that instruction.  Aircraft X was told to cross both runways; turn left on charlie; then uniform; Zulu to [maintenance].  He read the crossings back correctly then stammered through the remainder of the taxi instructions.  Since there were no other aircraft moving at the time.  He wasn't immediately corrected but I was able to focus on his crossing during my other work so that I could make sure he was following my instructions.  He crossed runway 28L and then said as he entered 28R; 'Clear of 28R'.  At this point I focused on him and then saw him make the turn down runway 28R and immediately told him that he had missed his turn and turned on to the runway.  I then instructed him to proceed right on taxiway kilo and then to turn left on to Charlie and continue to [maintenance].Changes recommended are either a change to the vehicle service road so that [Aircraft Y Types] can use it or a creation of another service road so that they can go around the departure ends without having to cross runways so that we can concentrate solely on aircraft under tow for crossings.




Synopsis: A Controller reports of a runway incursion he feels was due to a taxiway closure which limited special type aircraft not being able to use. The tug operator did most things correct but missed a turn and went onto an active runway as opposed to the taxiway. No other traffic was a factor.