Landing aircraft was possibly not going to completely clear the runway onto the taxiway; so the cont...

Narrative:

Aircraft X landed and rolled long. I made him aware that traffic on final behind him. He rolled to the end. It then became a squeaker. I had several tugs and people calling me on ground control and another controller trying to open to take the local control position. I was keeping an eye on the runway for the aircraft X to clear. It was going to be tight. [Another controller observing] had said they didn't think it was going [to] work; but it looked like it still may. Like I said I had tugs calling for re-position and was getting other calls on the combined frequencies. I let it ride as long as I could because I know these crews landing at that time of the morning are exhausted and just want to get on the ground and go home. I saw that aircraft X was across the line; but I couldn't make out if he was completely clear (tail) of the runway and nothing was impeding him. So I sent aircraft Y around. I probably could have done it a mile before; but like I said; I really hate sending these early morning arrivals around. I watched the asde-X replay and couldn't tell there either if the aircraft X was clear or not. I guess quality assurance will determine that. It was close. In the end I did the safe thing (subjective; thought the pilots were probably fully awake now) and sent him around. The asde-X never sounded.I would recommend that [airline company] wait 10-15 minutes later to start doing aircraft re-positions. Controller position relief is happening so we are conducting multiple relief briefings and we have a few arrivals opposite direction from the west coast and overseas at that time of day. 10-15 minutes later all is calm for the next half hour to 45 minutes. If you are busy on another frequency the tugs and especially the mechanics taxiing aircraft will continue to call. Not their fault; they aren't pilots or controllers. The company just needs to make it a policy not to move re-position aircraft until [15 minutes later]. Simply my opinion.like I said; I could have sent the second aircraft around sooner but I hate to do that especially to these guys who have been up all night.

Original NASA ASRS Text

Title: Landing aircraft was possibly not going to completely clear the runway onto the taxiway; so the Controller issued the subsequent arrival a go-around clearance. Reporter was not sure if required runway separation existed or not.

Narrative: Aircraft X landed and rolled long. I made him aware that traffic on final behind him. He rolled to the end. It then became a squeaker. I had several tugs and people calling me on ground control and another controller trying to open to take the local control position. I was keeping an eye on the runway for the Aircraft X to clear. It was going to be tight. [Another controller observing] had said they didn't think it was going [to] work; but it looked like it still may. Like I said I had tugs calling for re-position and was getting other calls on the combined frequencies. I let it ride as long as I could because I know these crews landing at that time of the morning are exhausted and just want to get on the ground and go home. I saw that Aircraft X was across the line; but I couldn't make out if he was completely clear (tail) of the runway and nothing was impeding him. So I sent Aircraft Y around. I probably could have done it a mile before; but like I said; I really hate sending these early morning arrivals around. I watched the ASDE-X replay and couldn't tell there either if the Aircraft X was clear or not. I guess Quality Assurance will determine that. It was close. In the end I did the safe thing (subjective; thought the pilots were probably fully awake now) and sent him around. The ASDE-X never sounded.I would recommend that [airline company] wait 10-15 minutes later to start doing aircraft re-positions. Controller position relief is happening so we are conducting multiple relief briefings and we have a few arrivals opposite direction from the west coast and overseas at that time of day. 10-15 minutes later all is calm for the next half hour to 45 minutes. If you are busy on another frequency the tugs and especially the mechanics taxiing aircraft will continue to call. Not their fault; they aren't pilots or controllers. The company just needs to make it a policy not to move re-position aircraft until [15 minutes later]. Simply my opinion.Like I said; I could have sent the second aircraft around sooner but I hate to do that especially to these guys who have been up all night.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1301146
Time
Date	201510
Local Time Of Day	0001-0600
Place
Locale Reference	IAH.Tower
State Reference	TX
Environment
Light	Dawn
Aircraft 1
Make Model Name	Widebody Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Route In Use	Visual Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Widebody Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Landing
Flight Plan	IFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 6.5
Events
Anomaly	ATC Issue All Types Conflict Ground Conflict Less Severe Deviation - Procedural Clearance Ground Incursion Runway

Landing aircraft was possibly not going to completely clear the runway onto the taxiway; so the controller issued the subsequent arrival a go-around clearance. Reporter was not sure if required runway separation existed or not.