ACR X HAD LTSS FROM ACR Y ON TKOF ROLL. SYS ERROR.

Narrative

ACFT CLRED FOR VISUAL APCH RWY 18R MCO; CLRED TO LAND. AT APPROX 1300 FT MSL (1200 FT AGL) TFC IN POS CLRED FOR TKOF. AT 1200 FT MSL; ACR Y MD-80 WAS CLRED TO POS AND HOLD. I ASKED TWR; 'IS THIS GOING TO WORK?' AND RECEIVED NO REPLY. AT 1000 FT MSL ACR Y IS CLRED FOR TKOF. PRECEDING ACFT IS NOT YET AIRBORNE. ACR Y STARTS TKOF ROLL AS PRECEDING ACFT LIFTS OFF. FO (PF) AND I DISCUSS POSSIBILITY OF A GAR. GAR IS NOT PREFERABLE DUE TO TSTMS E; S; AND W OF ARPT. ACR Y IS EVIDENTLY HVY; IT IS HOT (92 DEGS F). ACR Y USES A LOT OF RWY AND IS NOT AIRBORNE AS WE CROSS RWY THRESHOLD. I CALL GAR AND FO PERFORMS GAR. WHEN I RPT GAR TO TWR THEY SEEM SOMEWHAT SURPRISED; ISSUES US A TURN TO 140 DEG AND WE ARE VECTORED BACK FOR ANOTHER VISUAL APCH AND LAND UNEVENTFULLY ON RWY 18R. WE HAD ALL ACFT INVOLVED IN VISUAL CONTACT AT ALL TIMES. RWY 18L IS CLOSED AT MCO FOR CONSTRUCTION AND CTLRS SEEM TO HAVE A PROB THERE WITH ONLY 2 RWYS. CTLRS MAY NEED TRAINING OR REMINDING OF HOW LONG IT TAKES ACFT TO GET AIRBORNE UNDER HOT/HVY CONDITIONS. CTLRS SEEM TO TAKE THIS IN STRIDE BUT PAX AND PLTS DON'T. THIS IS A LESS THAN SAFE SIT.