ANC LCL CTLR EXPERIENCED OPERROR WITH 2 SUCCESSIVE DEP ACFT.

Narrative

I WAS WORKING THE LCL CTL POS IN A LIMITED RADAR APCH CTL TWR WHEN A FASTER DEP OVERTOOK A SLOWER PRECEDING DEP RESULTING IN A LOSS OF IFR SEPARATION. ARRS AND DEPS WERE UTILIZING RWY 24R AND RWY 14; A NONSTANDARD CONFIGN; DUE TO WIND. RWY 24L WAS CLOSED FOR MAINT. I HAD 'AUTO RELEASES' FOR BOTH RWYS. THIS MEANT I COULD USE BOTH RWYS FOR DEPS WITHOUT REQUESTING INDIVIDUAL RELEASES. BOTH ACFT WERE IN A SID THAT REQUIRED THE ACFT TO FLY RWY HDG AND TO EXPECT RADAR VECTORS ON COURSE. BOTH ACFT WERE INITIALLY ISSUED AN ALT OF 4000 FT. THE FIRST DEP; A DHC6; HAD DEPARTED AND HAD BEEN SWITCHED TO DEP CTL. BECAUSE OF ITS RTE OF FLT; A WSW HDG; THE ACFT WAS UNDER THE CTL OF THE S RADAR SECTOR. THE SECOND ACFT; A B737; WAS TAXIED INTO POS. THE ACFT WAS FILED ON A NORTHERLY RTE AND WOULD BE UNDER THE CTL OF THE N RADAR SECTOR. I COORDINATED WITH THE N RADAR HDOF POS AND REQUESTED A TURN TO A HDG OF 270 DEGS FOR THE B737. THE N RADAR HDOF CTLR DENIED THE TURN WITHOUT PROVIDING A REASON. I HAD ACFT WAITING TO DEPART ON BOTH RWYS. THE ACFT DEPARTING RWY 14 WAS A HVY ACFT. BECAUSE THE DEP FLT PATHS OF THE 2 RWYS INTERSECT AT THE ENDS; AND BECAUSE OF WAKE TURB ISSUES; IT WAS IMPERATIVE THAT THE RWY 24R DEP DEPARTED FIRST. WITHOUT A WESTERLY HDG FOR THE B737 I KNEW I WOULD HAVE TO PROVIDE OTHER SEPARATION. I HELD THE ACFT IN POS AS LONG AS PRACTICAL FOR IN-TRAIL SPACING PRIOR TO ISSUING TKOF CLRNC. I DROPPED THE DEP HALF OF THE FLT STRIP DOWN THE TUBE FOR N RADAR WHEN I CLRED THE B737 FOR TKOF. PER OUR FACILITY HANDBOOK; THIS INDICATES THAT THE ACFT IS ROLLING AND CONTAINS ACFT IDENT; ALT AND RTE INFO. WHEN THE ACFT BECAME AIRBORNE; THERE WAS APPROX 4 MI IN-TRAIL AND 2000 FT OF VERT SEPARATION. I IMMEDIATELY ISSUED TFC AND ANTICIPATED ESTABLISHING VISUAL SEPARATION WHEN THE ACFT RPTED THE TFC IN SIGHT. IN THE SAME XMISSION; I INADVERTENTLY CHANGED THE ACFT TO DEP. THE PLT REPLIED; 'LOOKING.' AFTER OTHER COORD AND XMISSIONS TO OTHER ACFT; I AGAIN ISSUED TFC TO THE B737. THIS TIME I INTENTIONALLY CHANGED THE ACFT TO DEP AS I HAD OBSERVED THE DHC6 TURNING SW AND OBSERVED THAT THE B737 WOULD PASS WELL N OF THE DHC6 AND THAT THERE WAS NO TFC TO THE W OR NW THAT WOULD PREVENT A TIMELY TURN IN THAT DIRECTION. THERE WAS; OF COURSE; NO REPLY AS THE PLT HAD ALREADY CHANGED FREQS. AS I CONTINUED TO WORK OTHER TFC; I OBSERVED THAT THE B737 HAD NOT BEEN TURNED BUT ITS COURSE WOULD TAKE IT N OF AND BEHIND THE DHC6 BY 1 MI OR MORE. I DID NOT OBSERVE A SAFETY ISSUE SO I DID NOT CALL THE RADAR POS TO DETERMINE WHY THE ACFT WAS STILL ON RWY HDG. WHEN; A FEW MINS LATER; I WAS RELIEVED FROM THE LCL CTL POS FOR NORMAL POS ROTATION; I PROMPTLY EXPLAINED TO THE SUPVR WHAT HAD TAKEN PLACE AND HEADED TO THE TRACON TO FIGURE OUT WHAT HAD HAPPENED. REVIEW OF THE TAPES INDICATED THAT THE B737 RPTED THE DHC6 IN SIGHT ON INITIAL CONTACT WHILE STILL 3 MI IN TRAIL. CONGESTION ON THE FREQ PREVENTED THE CTLR; WHO WAS TRAINING ON THE POS; FROM HEARING THE INITIAL XMISSION FROM THE B737 AND THUS MAINTAINING IFR SEPARATION. AFTER OTHER XMISSIONS ON THE FREQ; THE B737 AGAIN ATTEMPTED TO CONTACT DEP WITH THE TFC IN SIGHT. THE CTLR INITIALLY SOUNDED CONFUSED AS TO WHO WAS CALLING. HE LATER RADAR IDENTED THE ACFT AND TURNED THE ACFT TO THE N. WHEN THE PLT INQUIRED AS TO WHETHER THE CTLR HAD RECEIVED AN ALERT BTWN HE AND THE DHC6; THE CTLR ADVISED HIM TO MAINTAIN VISUAL SEPARATION. AT THIS POINT THE B737 HAD ALREADY PASSED BEHIND AND R OF THE DHC6 BY 1.09 MI AND THE LOSS OF SEPARATION HAD ALREADY OCCURRED. I BELIEVE THAT SEVERAL FACTORS CONTRIBUTED TO THIS LOSS OF SEPARATION. THE FIRST FACTOR WAS THE DENIAL OF THE REQUESTED HDG BY N RADAR HDOF. THE REQUEST WAS VALID AND TFC WAS NOT A FACTOR FOR DENYING THE TURN. THE TRAINER AND TRAINEE BOTH LATER TOLD ME THAT THERE WAS NO REASON TO NOT TURN THE ACFT. THE NEXT FACTOR WAS THE LACK OF COORD ABOUT THIS ACFT TO ANYONE BY THE N RADAR HDOF CTLR. UPON RECEIVING THE REQUESTED TURN AND LATER RECEIVING THE FLT STRIP FOR THE FASTER ACFT; THE CTLR KNEW THE ACFT WAS ROLLING AND COULD HAVE DONE ANY NUMBER OF THINGS TO ENSURE SEPARATION WAS MAINTAINED. AN APPROPRIATE TURN OR ALT RESTR COORDINATED WITH ME AT ANY POINT PRIOR TO THE FREQ CHANGE WOULD HAVE ENSURED A SMOOTH OP. ADDITIONALLY; A HEADS UP TO THE TRAINEE OR TRAINER THAT A FASTER ACFT WAS FOLLOWING A SLOWER ACFT WOULD HAVE ALERTED THE CTLR TO THE DECREASING SEPARATION. THE N RADAR HDOF CTLR COULD HAVE ALSO ALERTED ME TO THE FACT THAT TRAINING WAS IN PROGRESS AND THAT SECTOR SATURATION MIGHT PREVENT TIMELY XFER AND CTL INSTRUCTIONS. ANOTHER FACTOR WAS THE TRAINING ENVIRONMENT ON N RADAR DURING AN UNUSUAL RWY CONFIGN. THE TRAINEE WAS RECEIVING INSTRUCTION ON N RADAR SECTOR COMBINED WITH THE N LOW SECTOR AND THE FINAL N SECTOR. THE N LOW SECTOR IS NORMALLY DECOMBINED DURING HIGH TFC PERIODS AND FINAL N IS DECOMBINED WHEN TFC WARRANTS. THE AMOUNT OF TFC AND FREQ CONGESTION LIKELY CONTRIBUTED TO THE LACK OF AWARENESS OF N RADAR OF THE DECREASING SEPARATION TAKING PLACE IN A 'COLD SPOT;' AN AREA OF RELATIVE INACTIVITY. THE CTLR DID NOT EVEN SEEM TO BE AWARE THAT THE B737 WAS THERE UNTIL THE ACFT WAS FINALLY ABLE TO CHK IN. THEREFORE; HE WAS UNABLE TO INITIATE COMS AND CTL INSTRUCTIONS TO THE ACFT. THE S RADAR CTLR ASKED THE N RADAR CTLR IF HE WAS GOING TO TURN THE ACFT. THE N RADAR CTLR BELIEVED HE WAS TALKING ABOUT ANOTHER ACFT AND REPLIED THAT HE HAD ALREADY CHANGED THE ACFT TO TWR. A FINAL FACTOR FOR THE LOSS OF SEPARATION WAS MY LACK OF ESTABLISHING VISUAL SEPARATION BY INADVERTENTLY CHANGING THE FASTER ACFT TO DEP BEFORE TFC WAS RPTED IN SIGHT. HAD THE ACFT RPTED THE TFC IN SIGHT ON MY FREQ; I WOULD HAVE BEEN ABLE TO ESTABLISH VISUAL SEPARATION IN A TIMELY MANNER. PREVENTIVE MEASURES TO AVOID THIS TYPE OF INCIDENT IN THE FUTURE MAY INCLUDE REINFORCING THE 'TEAM CONCEPT' WHERE EACH CTLR STRIVES TO WORK TOGETHER TO MAINTAIN A SAFE OP AND TO ALERT OTHERS TO POTENTIAL CONFLICTS. ADDITIONALLY; PERHAPS TWRS AND TRACONS SHOULD HAVE A METHOD OF INFORMING EACH OTHER WHEN TRAINING IS TAKING PLACE AND OPS MAY NOT MOVE AT A NORMAL PACE.