Narrative:

I am a reserve captain at ZZZ. I was assigned the trip the day prior. I have flown the same pairing within the prior 45 days. I had not met or flown with my first officer prior to this. We accomplished a good crew brief prior to pushback. We pushed back on time from gate. Once clear of the terminal we accomplished the 'pre takeoff checklist.' company ahead was to the far left and we filled in the far right lane. Company was cleared for takeoff and departed. We then proceeded to shift left to hold short and I crossed the 'hold short line' for runway 31C. My first officer quickly informed me and he made a radio call to fess up and ask if we needed to make a 180 degree and get out of there. The tower controller acknowledged us and instantly gave one of our aircraft on a 1 1/2 mi final instructions to go around. Tower then gave 2 other aircraft instructions. Were asked tower again if we needed to move (we didn't want to move without his approval and did not know if anyone was behind us). Tower responded that he had given us 'position and hold' and 'now I had to send another aircraft around.' he sent an aircraft around and then gave us clearance for takeoff. We are certain tower never gave us the 'position and hold.' the remainder of the flight was uneventful. Possible factors were the multiple runway hold short lines and taxi lines. I believe I was looking at the wrong line, though it looks nothing like a hold short line. We were still 3 ship lengths away from the edge of the runway. I was not hurried, but my decision to move to the left so as to be in a better position for an expeditious takeoff was the key factor.

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Original NASA ASRS Text

Title: RWY 31C INCURSION AS PIC OF A B737-500 CROSSES A SET OF CONFUSING RWY HOLD LINES AT MDW, IL.

Narrative: I AM A RESERVE CAPT AT ZZZ. I WAS ASSIGNED THE TRIP THE DAY PRIOR. I HAVE FLOWN THE SAME PAIRING WITHIN THE PRIOR 45 DAYS. I HAD NOT MET OR FLOWN WITH MY FO PRIOR TO THIS. WE ACCOMPLISHED A GOOD CREW BRIEF PRIOR TO PUSHBACK. WE PUSHED BACK ON TIME FROM GATE. ONCE CLR OF THE TERMINAL WE ACCOMPLISHED THE 'PRE TKOF CHKLIST.' COMPANY AHEAD WAS TO THE FAR L AND WE FILLED IN THE FAR R LANE. COMPANY WAS CLRED FOR TKOF AND DEPARTED. WE THEN PROCEEDED TO SHIFT L TO HOLD SHORT AND I CROSSED THE 'HOLD SHORT LINE' FOR RWY 31C. MY FO QUICKLY INFORMED ME AND HE MADE A RADIO CALL TO FESS UP AND ASK IF WE NEEDED TO MAKE A 180 DEG AND GET OUT OF THERE. THE TWR CTLR ACKNOWLEDGED US AND INSTANTLY GAVE ONE OF OUR ACFT ON A 1 1/2 MI FINAL INSTRUCTIONS TO GO AROUND. TWR THEN GAVE 2 OTHER ACFT INSTRUCTIONS. WERE ASKED TWR AGAIN IF WE NEEDED TO MOVE (WE DIDN'T WANT TO MOVE WITHOUT HIS APPROVAL AND DID NOT KNOW IF ANYONE WAS BEHIND US). TWR RESPONDED THAT HE HAD GIVEN US 'POS AND HOLD' AND 'NOW I HAD TO SEND ANOTHER ACFT AROUND.' HE SENT AN ACFT AROUND AND THEN GAVE US CLRNC FOR TKOF. WE ARE CERTAIN TWR NEVER GAVE US THE 'POS AND HOLD.' THE REMAINDER OF THE FLT WAS UNEVENTFUL. POSSIBLE FACTORS WERE THE MULTIPLE RWY HOLD SHORT LINES AND TAXI LINES. I BELIEVE I WAS LOOKING AT THE WRONG LINE, THOUGH IT LOOKS NOTHING LIKE A HOLD SHORT LINE. WE WERE STILL 3 SHIP LENGTHS AWAY FROM THE EDGE OF THE RWY. I WAS NOT HURRIED, BUT MY DECISION TO MOVE TO THE L SO AS TO BE IN A BETTER POS FOR AN EXPEDITIOUS TKOF WAS THE KEY FACTOR.

Data retrieved from NASA's ASRS site as of July 2007 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.